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<title>Signal modulation</title>

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<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Signal modulation</span></span>

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</style><div role="note" class="hatnote navigation-not-searchable">This article is about the electronic method to imprint data on a transmitted carrier wave. For other uses of 'Modulation', see <a href="Modulation_(disambiguation)" class="mw-disambig" title="Modulation (disambiguation)">Modulation (disambiguation)</a>.</div>

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<a class="mw-selflink-fragment" href="#Analog_modulation_methods">Analog modulation</a></th></tr><tr><td class="sidebar-content hlist" style="color: black;">

<li><a href="Angle_modulation" title="Angle modulation">Angle modulation</a>

</tr><tr><th class="sidebar-heading" style="background-color: #cfc;">

<a class="mw-selflink-fragment" href="#Digital_modulation_methods">Digital modulation</a></th></tr><tr><td class="sidebar-content hlist" style="color: black;">

</tr><tr><th class="sidebar-heading" style="background-color: #cfc;">

<a href="Hierarchical_modulation" title="Hierarchical modulation">Hierarchical modulation</a></th></tr><tr><td class="sidebar-content hlist" style="color: black;">

</tr><tr><th class="sidebar-heading" style="background-color: #cfc;">

<a href="Spread_spectrum" title="Spread spectrum">Spread spectrum</a></th></tr><tr><td class="sidebar-content hlist" style="color: black;">

</tr><tr><th class="sidebar-heading" style="background-color: #cfc;">

See also</th></tr><tr><td class="sidebar-content hlist" style="color: black;">

<ul><li>Capacity-approaching codes</li>

<li><a href="Demodulation" title="Demodulation">Demodulation</a></li>

<li><a href="Line_code" title="Line code">Line coding</a></li>

<li><a href="Modem" title="Modem">Modem</a></li>

<li><a href="Multiplexing" title="Multiplexing">Multiplexing</a></li></ul></td>

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<p><b>Signal modulation</b> is the process of varying one or more properties of a periodic <a href="Waveform" title="Waveform">waveform</a> in <a href="Electronics" title="Electronics">electronics</a> and <a href="Telecommunication" class="mw-redirect" title="Telecommunication">telecommunication</a> for the purpose of transmitting information.

</p><p>The process encodes information in form of the modulation or message signal onto a <a href="Carrier_signal" class="mw-redirect" title="Carrier signal">carrier signal</a> to be transmitted.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> For example, the message signal might be an <a href="Audio_signal" title="Audio signal">audio signal</a> representing <a href="Sound" title="Sound">sound</a> from a <a href="Microphone" title="Microphone">microphone</a>, a <a href="Video_signal" class="mw-redirect" title="Video signal">video signal</a> representing moving images from a <a href="Video_camera" title="Video camera">video camera</a>, or a <a href="Digital_signal" title="Digital signal">digital signal</a> representing a sequence of binary digits, a <a href="Bitstream" title="Bitstream">bitstream</a> from a computer.

</p><p>This carrier wave usually has a much higher <a href="Frequency" title="Frequency">frequency</a> than the message signal does. This is because it is impractical to transmit signals with low frequencies. Generally, receiving a <a href="Radio_wave" title="Radio wave">radio wave</a> requires a <a href="Radio_antenna" class="mw-redirect" title="Radio antenna">radio antenna</a> with a length that is one-fourth of the wavelength of the transmitted wave.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> For low frequency radio waves, wavelength is on the scale of kilometers and building such a large antenna is not practical.

</p><p>Another purpose of modulation is to transmit multiple <a href="Communication_channel" title="Communication channel">channels</a> of information through a single <a href="Transmission_medium" title="Transmission medium">communication medium</a>, using <a href="Frequency-division_multiplexing" title="Frequency-division multiplexing">frequency-division multiplexing</a> (FDM). For example, in <a href="Cable_television" title="Cable television">cable television</a> (which uses FDM), many carrier signals, each modulated with a different <a href="Television_channel" title="Television channel">television channel</a>, are transported through a single cable to customers. Since each carrier occupies a different frequency, the channels do not interfere with each other. At the destination end, the carrier signal is <a href="Demodulation" title="Demodulation">demodulated</a> to extract the information bearing modulation signal.

</p><p>A <b>modulator</b> is a device or <a href="Electric_circuit" class="mw-redirect" title="Electric circuit">circuit</a> that performs modulation. A <b>demodulator</b> (sometimes <i><a href="Detector_(radio)" title="Detector (radio)">detector</a></i>) is a circuit that performs <a href="Demodulation" title="Demodulation">demodulation</a>, the inverse of modulation. A <a href="Modem" title="Modem">modem</a> (from <b>mod</b>ulator–<b>dem</b>odulator), used in bidirectional communication, can perform both operations. The lower frequency band occupied by the modulation signal is called the <i><a href="Baseband" title="Baseband">baseband</a></i>, while the higher frequency band occupied by the modulated carrier is called the <i><a href="Passband" title="Passband">passband</a></i>.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup>

</p><p>Signal modulation techniques are fundamental methods used in wireless communication to encode information onto a carrier wave by varying its amplitude, frequency, or phase. Key techniques and their typical applications

</p><p><b>Types of Signal Modulation</b><sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup>

</p>

</caption>

<th>Category

</th>

<th>Modulation Type

</th>

<th>Key Features

</th>

<th>Example Uses

</th></tr>

<tr>

<td><b>Analog Modulation</b>

</td>

<td>AM

</td>

<td>Varies Amplitude of Carrier

</td>

<td>AM Radio

</td></tr>

<tr>

<td>

</td>

<td>FM

</td>

<td>Varies Frequency of Carrier

</td>

<td>FM and Two-way Radio

</td></tr>

<tr>

<td>

</td>

<td>PM

</td>

<td>Varies Phase of Carrier

</td>

<td>Analog TV and Satellite

</td></tr>

<tr>

<td><b>Digital Modulation</b>

</td>

<td>ASK

</td>

<td>Amplitude represents binary data

</td>

<td>RFID, Optical Comm

</td></tr>

<tr>

<td>

</td>

<td>FSK

</td>

<td>Frequency shift encodes data

</td>

<td>Modems, Bluetooth

</td></tr>

<tr>

<td>

</td>

<td>PSK

</td>

<td>Phase of carrier encodes bits

</td>

<td>Wi-Fi, Satellite

</td></tr>

<tr>

<td>

</td>

<td>QPSK

</td>

<td>4 phase states: two bits per symbol

</td>

<td>DVB, LTE

</td></tr>

<tr>

<td>

</td>

<td>QAM

</td>

<td>Both amplitude and phase vary; can transmit multiple bits

</td>

<td>Cable TV, Wi-Fi

</td></tr>

<tr>

<td>

</td>

<td>OFDM

</td>

<td>Multiple carriers, each modulated separately

</td>

<td>4G/5G, Wi-Fi

</td></tr>

<tr>

<td><b>Pulse Modulation</b>

</td>

<td>PWM

</td>

<td>Pulse width represents amplitude

</td>

<td>Motor Control, Audio

</td></tr>

<tr>

<td>

</td>

<td>PPM

</td>

<td>Pulse position within a time slot represents data

</td>

<td>Optical Comm., Radar

</td></tr>

<tr>

<td><b>Spread Spectrum</b>

</td>

<td>DSSS

</td>

<td>Signal bandwidth spread using code sequence

</td>

<td>CDMA, GPS

</td></tr>

<tr>

<td>

</td>

<td>FHSS

</td>

<td>Carrier hops between different frequencies

</td>

<td>Bluetooth, Military

</td></tr></tbody></table>

<p>•Amplitude Shift Keying (ASK): Varies the amplitude of the carrier signal to represent data. Simple and energy efficient, but vulnerable to noise. Used in RFID and sensor networks.<sup id="cite_ref-:0_8-0" class="reference"><a href="#cite_note-:0-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup>

</p><p>•Frequency Shift Keying (FSK): Changes the frequency of the carrier signal to encode information. Resistant to noise, simple in implementation, often used in telemetry and paging systems.<sup id="cite_ref-:0_8-1" class="reference"><a href="#cite_note-:0-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup>

</p><p>•Phase Shift Keying (PSK): Modifies the phase of the carrier signal based on data. Common forms include Binary PSK (BPSK) and Quadrature PSK (QPSK), used in Wi-Fi, Bluetooth, and cellular networks. Offers good spectral efficiency and robustness against interference.<sup id="cite_ref-:0_8-2" class="reference"><a href="#cite_note-:0-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup>

</p><p>•Quadrature Amplitude Modulation (QAM): Simultaneously varies both amplitude and phase to transmit multiple bits per symbol, increasing data rates. Used extensively in Wi-Fi, cable television, and LTE systems.<sup id="cite_ref-:0_8-3" class="reference"><a href="#cite_note-:0-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup>

</p><p>•Orthogonal Frequency Division Multiplexing (OFDM): Splits the data across multiple, closely spaced sub-carriers, each modulated separately (often with QAM or PSK). Provides high spectral efficiency and robustness in multipath environments and is widely used in WLAN, LTE, and WiMAX.<sup id="cite_ref-:0_8-4" class="reference"><a href="#cite_note-:0-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup>

</p><p>•Other advanced techniques:

</p><p>•Amplitude Phase Shift Keying (APSK): Combines features of PSK and QAM, mainly used in satellite communications for improved power efficiency.

</p><p>•Spread Spectrum (e.g., DSSS): Spreads the signal energy across a wide band for robust, low probability of intercept transmission.

</p><p>In <b>analog modulation</b>, an <a href="Analog_signal" title="Analog signal">analog</a> modulation signal is "impressed" on the carrier. Examples are <a href="Amplitude_modulation" title="Amplitude modulation">amplitude modulation</a> (AM) in which the <a href="Amplitude" title="Amplitude">amplitude</a> (strength) of the carrier wave is varied by the modulation signal, and <a href="Frequency_modulation" title="Frequency modulation">frequency modulation</a> (FM) in which the <a href="Frequency" title="Frequency">frequency</a> of the carrier wave is varied by the modulation signal. These were the earliest types of modulation, and are used to transmit an <a href="Audio_signal" title="Audio signal">audio signal</a> representing sound in AM and FM <a href="Radio_broadcasting" title="Radio broadcasting">radio broadcasting</a>. More recent systems use <b>digital modulation</b>, which impresses a <a href="Digital_signal" title="Digital signal">digital signal</a> consisting of a sequence of <a href="Binary_digit" class="mw-redirect" title="Binary digit">binary digits</a> (bits), a <a href="Bitstream" title="Bitstream">bitstream</a>, on the carrier, by means of mapping bits to elements from a discrete alphabet to be transmitted. This alphabet can consist of a set of real or <a href="Complex_number" title="Complex number">complex numbers</a>, or sequences, like oscillations of different frequencies, so-called <a href="Frequency-shift_keying" title="Frequency-shift keying">frequency-shift keying</a> (FSK) modulation. A more complicated digital modulation method that employs multiple carriers, <a href="Orthogonal_frequency-division_multiplexing" title="Orthogonal frequency-division multiplexing">orthogonal frequency-division multiplexing</a> (OFDM), is used in <a href="WiFi" class="mw-redirect" title="WiFi">WiFi</a> networks, <a href="Digital_radio" title="Digital radio">digital radio</a> stations and digital cable television transmission.

</p>

<div class="mw-heading mw-heading2"><h2 id="Analog_modulation_methods">Analog modulation methods</h2></div>

<p>In <a href="Analog_signal" title="Analog signal">analog</a> modulation, the modulation is applied continuously in response to the analog information signal. Common analog modulation techniques include:

</p>

<ul><li><a href="Amplitude_modulation" title="Amplitude modulation">Amplitude modulation</a> (AM) (here the amplitude of the carrier signal is varied in accordance with the instantaneous amplitude of the modulating signal)

<ul><li>Double-sideband modulation (DSB)

<ul><li>Double-sideband modulation with carrier (DSB-WC) (used on the AM radio broadcasting band)</li>

<li><a href="Double-sideband_suppressed-carrier_transmission" title="Double-sideband suppressed-carrier transmission">Double-sideband suppressed-carrier transmission</a> (DSB-SC)</li>

<li><a href="Double-sideband_reduced_carrier_transmission" class="mw-redirect" title="Double-sideband reduced carrier transmission">Double-sideband reduced carrier transmission</a> (DSB-RC)</li></ul></li>

<li><a href="Single-sideband_modulation" title="Single-sideband modulation">Single-sideband modulation</a> (SSB, or SSB-AM)

<ul><li>Single-sideband modulation with carrier (SSB-WC)</li>

<li>Single-sideband modulation suppressed carrier modulation (SSB-SC)</li></ul></li>

<li><a href="Vestigial_sideband_modulation" class="mw-redirect" title="Vestigial sideband modulation">Vestigial sideband modulation</a> (VSB, or VSB-AM)</li>

<li><a href="Quadrature_amplitude_modulation" title="Quadrature amplitude modulation">Quadrature amplitude modulation</a> (QAM)</li></ul></li>

<li><a href="Angle_modulation" title="Angle modulation">Angle modulation</a>, which is approximately <a href="Constant_envelope" title="Constant envelope">constant envelope</a>

<ul><li><a href="Frequency_modulation" title="Frequency modulation">Frequency modulation</a> (FM) (here the frequency of the carrier signal is varied in accordance with the instantaneous amplitude of the modulating signal)</li>

<li><a href="Phase_modulation" title="Phase modulation">Phase modulation</a> (PM) (here the phase shift of the carrier signal is varied in accordance with the instantaneous amplitude of the modulating signal)</li>

<li>Transpositional Modulation (TM), in which the waveform inflection is modified resulting in a signal where each quarter cycle is transposed in the modulation process. TM is a pseudo-analog modulation (AM). Where an AM carrier also carries a phase variable phase f(ǿ). TM is f(AM,ǿ)</li></ul></li></ul>

<div class="mw-heading mw-heading2"><h2 id="Digital_modulation_methods">Digital modulation methods</h2></div>

<p>In <a href="Digital_data" title="Digital data">digital</a> modulation, an analog carrier signal is modulated by a discrete signal. Digital modulation methods can be considered as digital-to-analog conversion and the corresponding <a href="Demodulation" title="Demodulation">demodulation</a> or detection as analog-to-digital conversion. The changes in the carrier signal are chosen from a finite number of M alternative symbols (the <i>modulation alphabet</i>).

</p>

<blockquote><p><b>A simple example:</b> A telephone line is designed for transferring audible sounds, for example, tones, and not digital bits (zeros and ones). Computers may, however, communicate over a telephone line by means of modems, which are representing the digital bits by tones, called symbols. If there are four alternative symbols (corresponding to a musical instrument that can generate four different tones, one at a time), the first symbol may represent the bit sequence 00, the second 01, the third 10 and the fourth 11. If the modem plays a melody consisting of 1000 tones per second, the <a href="Symbol_rate" title="Symbol rate">symbol rate</a> is 1000 symbols/second, or 1000 <a href="Baud" title="Baud">baud</a>. Since each tone (i.e., symbol) represents a message consisting of two digital bits in this example, the <a href="Bit_rate" title="Bit rate">bit rate</a> is twice the symbol rate, i.e. 2000 bits per second.</p></blockquote>

<p>According to one definition of <a href="Digital_signal" title="Digital signal">digital signal</a>,<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> the modulated signal is a digital signal. According to another definition, the modulation is a form of <a href="Digital-to-analog_conversion" class="mw-redirect" title="Digital-to-analog conversion">digital-to-analog conversion</a>. Most textbooks would consider digital modulation schemes as a form of <a href="Digital_transmission" class="mw-redirect" title="Digital transmission">digital transmission</a>, synonymous to data transmission; very few would consider it as <a href="Analog_transmission" title="Analog transmission">analog transmission</a>.

</p>

<div class="mw-heading mw-heading3"><h3 id="Fundamental_digital_modulation_methods">Fundamental digital modulation methods</h3></div>

<p>The most fundamental digital modulation techniques are based on <a href="Keying_(telecommunications)" title="Keying (telecommunications)">keying</a>:

</p>

<ul><li><a href="Phase-shift_keying" title="Phase-shift keying">PSK (phase-shift keying)</a>: a finite number of phases are used.</li>

<li><a href="Frequency-shift_keying" title="Frequency-shift keying">FSK (frequency-shift keying)</a>: a finite number of frequencies are used.</li>

<li><a href="Amplitude-shift_keying" title="Amplitude-shift keying">ASK (amplitude-shift keying)</a>: a finite number of amplitudes are used.</li>

<li><a href="Quadrature_amplitude_modulation" title="Quadrature amplitude modulation">QAM (quadrature amplitude modulation)</a>: a finite number of at least two phases and at least two amplitudes are used.</li></ul>

<p>In QAM, an in-phase signal (or I, with one example being a cosine waveform) and a quadrature phase signal (or Q, with an example being a sine wave) are amplitude modulated with a finite number of amplitudes and then summed. It can be seen as a two-channel system, each channel using ASK. The resulting signal is equivalent to a combination of PSK and ASK.

</p><p>In all of the above methods, each of these phases, frequencies or amplitudes are assigned a unique pattern of <a href="Binary_numeral_system" class="mw-redirect" title="Binary numeral system">binary</a> <a href="Bit" title="Bit">bits</a>. Usually, each phase, frequency or amplitude encodes an equal number of bits. This number of bits comprises the <i>symbol</i> that is represented by the particular phase, frequency or amplitude.

</p><p>If the alphabet consists of <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle M=2^{N}}">

<msup>

</mrow>

</msup>

</mstyle>

</mrow>

<annotation encoding="application/x-tex">{\displaystyle M=2^{N}}</annotation>

</semantics>

</math></span><img src="./2aaa5bdbbea857a913997a146a038f6b5242cfca.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:8.395ex; height:2.676ex;" alt="{\displaystyle M=2^{N}}" loading="lazy"></span> alternative symbols, each symbol represents a message consisting of <i>N</i> bits. If the <a href="Symbol_rate" title="Symbol rate">symbol rate</a> (also known as the <a href="Baud_rate" class="mw-redirect" title="Baud rate">baud rate</a>) is <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle f_{S}}">

<msub>

</mrow>

</msub>

</mstyle>

</mrow>

<annotation encoding="application/x-tex">{\displaystyle f_{S}}</annotation>

</semantics>

</math></span><img src="./2b44c97f83aebb50c3fd26b567ff9b005dc7b82b.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.432ex; height:2.509ex;" alt="{\displaystyle f_{S}}" loading="lazy"></span> symbols/second (or <a href="Baud" title="Baud">baud</a>), the data rate is <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle Nf_{S}}">

<msub>

</mrow>

</msub>

</mstyle>

</mrow>

<annotation encoding="application/x-tex">{\displaystyle Nf_{S}}</annotation>

</semantics>

</math></span><img src="./012032b67484aae0657343d728c099ff544e22a6.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:4.495ex; height:2.509ex;" alt="{\displaystyle Nf_{S}}" loading="lazy"></span> bit/second.

</p><p>For example, with an alphabet consisting of 16 alternative symbols, each symbol represents 4 bits. Thus, the data rate is four times the baud rate.

</p><p>In the case of PSK, ASK or QAM, where the carrier frequency of the modulated signal is constant, the modulation alphabet is often conveniently represented on a <a href="Constellation_diagram" title="Constellation diagram">constellation diagram</a>, showing the amplitude of the I signal at the x-axis, and the amplitude of the Q signal at the y-axis, for each symbol.

</p>

<div class="mw-heading mw-heading3"><h3 id="Modulator_and_detector_principles_of_operation">Modulator and detector principles of operation</h3></div>

<p>PSK and ASK, and sometimes also FSK, are often generated and detected using the principle of QAM. The I and Q signals can be combined into a <a href="Complex-valued" class="mw-redirect" title="Complex-valued">complex-valued</a> signal <i>I</i>+<i>jQ</i> (where <i>j</i> is the <a href="Imaginary_unit" title="Imaginary unit">imaginary unit</a>). The resulting so called <a href="Equivalent_lowpass_signal" class="mw-redirect" title="Equivalent lowpass signal">equivalent lowpass signal</a> or <a href="Equivalent_baseband_signal" class="mw-redirect" title="Equivalent baseband signal">equivalent baseband signal</a> is a complex-valued representation of the <a href="Real-valued" class="mw-redirect" title="Real-valued">real-valued</a> modulated physical signal (the so-called <a href="Passband_signal" class="mw-redirect" title="Passband signal">passband signal</a> or <a href="RF_signal" class="mw-redirect" title="RF signal">RF signal</a>).

</p><p>These are the general steps used by the <a href="Modulator" class="mw-redirect" title="Modulator">modulator</a> to transmit data:

</p>

<ol><li>Group the incoming data bits into codewords, one for each symbol that will be transmitted.</li>

<li>Map the codewords to attributes, for example, amplitudes of the I and Q signals (the equivalent low pass signal), or frequency or phase values.</li>

<li>Adapt <a href="Pulse_shaping" title="Pulse shaping">pulse shaping</a> or some other filtering to limit the bandwidth and form the spectrum of the equivalent low pass signal, typically using digital signal processing.</li>

<li>Perform digital to analog conversion (DAC) of the I and Q signals (since today all of the above is normally achieved using <a href="Digital_signal_processing" title="Digital signal processing">digital signal processing</a>, DSP).</li>

<li>Generate a high-frequency sine carrier waveform, and perhaps also a cosine quadrature component. Carry out the modulation, for example by multiplying the sine and cosine waveform with the I and Q signals, resulting in the equivalent low pass signal being frequency shifted to the modulated <a href="Passband_signal" class="mw-redirect" title="Passband signal">passband signal</a> or RF signal. Sometimes this is achieved using DSP technology, for example <a href="Direct_digital_synthesis" title="Direct digital synthesis">direct digital synthesis</a> using a waveform table, instead of analog signal processing. In that case, the above DAC step should be done after this step.</li>

<li>Amplification and analog bandpass filtering to avoid harmonic distortion and periodic spectrum.</li></ol>

<p>At the receiver side, the <a href="Demodulator" class="mw-redirect" title="Demodulator">demodulator</a> typically performs:

</p>

<ol><li>Bandpass filtering.</li>

<li><a href="Automatic_gain_control" title="Automatic gain control">Automatic gain control</a>, AGC (to compensate for <a href="Attenuation" title="Attenuation">attenuation</a>, for example <a href="Fading" title="Fading">fading</a>).</li>

<li>Frequency shifting of the RF signal to the equivalent baseband I and Q signals, or to an intermediate frequency (IF) signal, by multiplying the RF signal with a local oscillator sine wave and cosine wave frequency (see the <a href="Superheterodyne_receiver" title="Superheterodyne receiver">superheterodyne receiver</a> principle).</li>

<li>Sampling and analog-to-digital conversion (ADC) (sometimes before or instead of the above point, for example by means of <a href="Undersampling" title="Undersampling">undersampling</a>).</li>

<li>Equalization filtering, for example, a <a href="Matched_filter" title="Matched filter">matched filter</a>, compensation for multipath propagation, time spreading, phase distortion and frequency selective fading, to avoid <a href="Intersymbol_interference" title="Intersymbol interference">intersymbol interference</a> and symbol distortion.</li>

<li>Detection of the amplitudes of the I and Q signals, or the frequency or phase of the IF signal.</li>

<li>Quantization of the amplitudes, frequencies or phases to the nearest allowed symbol values.</li>

<li>Mapping of the quantized amplitudes, frequencies or phases to codewords (bit groups).</li>

<li>Parallel-to-serial conversion of the codewords into a bit stream.</li>

<li>Pass the resultant bit stream on for further processing such as removal of any error-correcting codes.</li></ol>

<p>As is common to all digital communication systems, the design of both the modulator and demodulator must be done simultaneously. Digital modulation schemes are possible because the transmitter-receiver pair has prior knowledge of how data is encoded and represented in the communications system. In all digital communication systems, both the modulator at the transmitter and the demodulator at the receiver are structured so that they perform inverse operations.

</p><p>Asynchronous methods do not require a receiver reference clock signal that is <a href="Phase_synchronisation" class="mw-redirect" title="Phase synchronisation">phase synchronized</a> with the sender <a href="Carrier_signal" class="mw-redirect" title="Carrier signal">carrier signal</a>. In this case, modulation symbols (rather than bits, characters, or data packets) are <a href="Asynchronous_communication" title="Asynchronous communication">asynchronously</a> transferred. The opposite is <a href="Bit-synchronous_operation" title="Bit-synchronous operation">synchronous modulation</a>.

</p>

<div class="mw-heading mw-heading3"><h3 id="List_of_common_digital_modulation_techniques">List of common digital modulation techniques</h3></div>

<p>The most common digital modulation techniques are:

</p>

<ul><li><a href="Phase-shift_keying" title="Phase-shift keying">Phase-shift keying</a> (PSK)

<ul><li>Binary PSK (BPSK), using M=2 symbols</li>

<li>Quadrature PSK (QPSK), using M=4 symbols</li>

<li>8PSK, using M=8 symbols</li>

<li>16PSK, using M=16 symbols</li>

<li>Differential PSK (DPSK)</li>

<li>Differential QPSK (DQPSK)</li>

<li>Offset QPSK (<a href="OQPSK" class="mw-redirect" title="OQPSK">OQPSK</a>)</li>

<li><a href="Frequency-shift_keying" title="Frequency-shift keying">Frequency-shift keying</a> (FSK)

<ul><li><a href="Audio_frequency-shift_keying" class="mw-redirect" title="Audio frequency-shift keying">Audio frequency-shift keying</a> (AFSK)</li>

<li><a href="Multi-frequency_shift_keying" class="mw-redirect" title="Multi-frequency shift keying">Multi-frequency shift keying</a> (M-ary FSK or MFSK)</li>

<li><a href="Dual-tone_multi-frequency_signaling" class="mw-redirect" title="Dual-tone multi-frequency signaling">Dual-tone multi-frequency signaling</a> (DTMF)</li></ul></li>

<li><a href="Amplitude-shift_keying" title="Amplitude-shift keying">Amplitude-shift keying</a> (ASK)</li>

<li><a href="On-off_keying" class="mw-redirect" title="On-off keying">On-off keying</a> (OOK), the most common ASK form

<ul><li>M-ary <a href="Vestigial_sideband_modulation" class="mw-redirect" title="Vestigial sideband modulation">vestigial sideband modulation</a>, for example <a href="8VSB" title="8VSB">8VSB</a></li></ul></li>

<li><a href="Quadrature_amplitude_modulation" title="Quadrature amplitude modulation">Quadrature amplitude modulation</a> (QAM), a combination of PSK and ASK

<ul><li><a href="Polar_modulation" title="Polar modulation">Polar modulation</a> like QAM a combination of PSK and ASK</li></ul></li>

<li><a href="Continuous_phase_modulation" title="Continuous phase modulation">Continuous phase modulation</a> (CPM) methods

<ul><li><a href="Minimum-shift_keying" title="Minimum-shift keying">Minimum-shift keying</a> (MSK)</li>

<li><a href="Gaussian_minimum-shift_keying" class="mw-redirect" title="Gaussian minimum-shift keying">Gaussian minimum-shift keying</a> (GMSK)</li>

<li><a href="Continuous-phase_frequency-shift_keying" class="mw-redirect" title="Continuous-phase frequency-shift keying">Continuous-phase frequency-shift keying</a> (CPFSK)</li></ul></li>

<li><a href="Orthogonal_frequency-division_multiplexing" title="Orthogonal frequency-division multiplexing">Orthogonal frequency-division multiplexing</a> (OFDM) modulation

<ul><li><a href="Discrete_multitone" class="mw-redirect" title="Discrete multitone">Discrete multitone</a> (DMT), including adaptive modulation and bit-loading</li></ul></li>

<li><a href="Wavelet_modulation" title="Wavelet modulation">Wavelet modulation</a></li>

<li><a href="Trellis_coded_modulation" title="Trellis coded modulation">Trellis coded modulation</a> (TCM), also known as <a href="Trellis_modulation" class="mw-redirect" title="Trellis modulation">Trellis modulation</a></li>

<li><a href="Spread_spectrum" title="Spread spectrum">Spread spectrum</a> techniques

<ul><li><a href="Direct-sequence_spread_spectrum" title="Direct-sequence spread spectrum">Direct-sequence spread spectrum</a> (DSSS)</li>

<li><a href="Chirp_spread_spectrum" title="Chirp spread spectrum">Chirp spread spectrum</a> (CSS) according to IEEE 802.15.4a CSS uses pseudo-stochastic coding</li>

<li><a href="Frequency-hopping_spread_spectrum" title="Frequency-hopping spread spectrum">Frequency-hopping spread spectrum</a> (FHSS) applies a special scheme for channel release</li></ul></li></ul>

<p><a href="Minimum-shift_keying" title="Minimum-shift keying">MSK</a> and <a href="GMSK" class="mw-redirect" title="GMSK">GMSK</a> are particular cases of continuous phase modulation. Indeed, MSK is a particular case of the sub-family of CPM known as <a href="Continuous-phase_frequency-shift_keying" class="mw-redirect" title="Continuous-phase frequency-shift keying">continuous-phase frequency-shift keying</a> (CPFSK) which is defined by a rectangular frequency pulse (i.e. a linearly increasing phase pulse) of one-symbol-time duration (total response signaling).

</p><p><a href="OFDM" class="mw-redirect" title="OFDM">OFDM</a> is based on the idea of <a href="Frequency-division_multiplexing" title="Frequency-division multiplexing">frequency-division multiplexing</a> (FDM), but the multiplexed streams are all parts of a single original stream. The bit stream is split into several parallel data streams, each transferred over its own sub-carrier using some conventional digital modulation scheme. The modulated sub-carriers are summed to form an OFDM signal. This dividing and recombining help with handling channel impairments. OFDM is considered as a modulation technique rather than a multiplex technique since it transfers one bit stream over one communication channel using one sequence of so-called OFDM symbols. OFDM can be extended to multi-user <a href="Channel_access_method" title="Channel access method">channel access method</a> in the <a href="Orthogonal_frequency-division_multiple_access" title="Orthogonal frequency-division multiple access">orthogonal frequency-division multiple access</a> (OFDMA) and <a href="Multi-carrier_code-division_multiple_access" title="Multi-carrier code-division multiple access">multi-carrier code-division multiple access</a> (MC-CDMA) schemes, allowing several users to share the same physical medium by giving different sub-carriers or spreading codes to different users.

</p><p>Of the two kinds of <a href="RF_power_amplifier" title="RF power amplifier">RF power amplifier</a>, <a href="Switching_amplifier" class="mw-redirect" title="Switching amplifier">switching amplifiers</a> (<a href="Class_D_amplifier" class="mw-redirect" title="Class D amplifier">Class D amplifiers</a>) cost less and use less battery power than <a href="Linear_amplifier" title="Linear amplifier">linear amplifiers</a> of the same output power. However, they only work with relatively constant-amplitude-modulation signals such as angle modulation (FSK or PSK) and <a href="CDMA" class="mw-redirect" title="CDMA">CDMA</a>, but not with QAM and OFDM. Nevertheless, even though switching amplifiers are completely unsuitable for normal QAM constellations, often the QAM modulation principle are used to drive switching amplifiers with these FM and other waveforms, and sometimes QAM demodulators are used to receive the signals put out by these switching amplifiers.

</p>

<div class="mw-heading mw-heading3"><h3 id="Automatic_digital_modulation_recognition_(ADMR)">Automatic digital modulation recognition (ADMR)</h3></div>

<p>Automatic digital modulation recognition in intelligent communication systems is one of the most important issues in <a href="Software-defined_radio" title="Software-defined radio">software-defined radio</a> and <a href="Cognitive_radio" title="Cognitive radio">cognitive radio</a>. According to incremental expanse of intelligent receivers, automatic modulation recognition becomes a challenging topic in telecommunication systems and computer engineering. Such systems have many civil and military applications. Moreover, blind recognition of modulation type is an important problem in commercial systems, especially in <a href="Software-defined_radio" title="Software-defined radio">software-defined radio</a>. Usually in such systems, there are some extra information for system configuration, but considering blind approaches in intelligent receivers, we can reduce information overload and increase transmission performance. Obviously, with no knowledge of the transmitted data and many unknown parameters at the receiver, such as the signal power, carrier frequency and phase offsets, timing information, etc., blind identification of the modulation is made fairly difficult. This becomes even more challenging in real-world scenarios with multipath fading, frequency-selective and time-varying channels.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup>

</p><p>There are two main approaches to automatic modulation recognition. The first approach uses likelihood-based methods to assign an input signal to a proper class. Another recent approach is based on feature extraction.

</p>

<div class="mw-heading mw-heading3"><h3 id="Digital_baseband_modulation">Digital baseband modulation</h3></div>

<p>Digital baseband modulation changes the characteristics of a baseband signal, i.e., one without a carrier at a higher frequency.

</p><p>This can be used as equivalent signal to be later <a href="Frequency_mixer" title="Frequency mixer">frequency-converted</a> to a carrier frequency, or for direct communication in baseband. The latter methods both involve relatively simple <a href="Line_code" title="Line code">line codes</a>, as often used in local buses, and complicated baseband signalling schemes such as used in <a href="DSL" class="mw-redirect" title="DSL">DSL</a>.

</p>

<div class="mw-heading mw-heading2"><h2 id="Pulse_modulation_methods">Pulse modulation methods</h2></div>

<p>Pulse modulation schemes aim at transferring a narrowband analog signal over an analog baseband channel as a two-level signal by modulating a <a href="Pulse_wave" title="Pulse wave">pulse wave</a>. Some pulse modulation schemes also allow the narrowband analog signal to be transferred as a digital signal (i.e., as a <a href="Quantization_(signal_processing)" title="Quantization (signal processing)">quantized</a> <a href="Discrete-time_signal" class="mw-redirect" title="Discrete-time signal">discrete-time signal</a>) with a fixed bit rate, which can be transferred over an underlying digital transmission system, for example, some <a href="Line_code" title="Line code">line code</a>. These are not modulation schemes in the conventional sense since they are not <a href="Channel_coding" class="mw-redirect" title="Channel coding">channel coding</a> schemes, but should be considered as <a href="Source_coding" class="mw-redirect" title="Source coding">source coding</a> schemes, and in some cases analog-to-digital conversion techniques.

</p>

<dl><dt>Analog-over-analog methods</dt></dl>

<ul><li><a href="Pulse-amplitude_modulation" title="Pulse-amplitude modulation">Pulse-amplitude modulation</a> (PAM)</li>

<li><a href="Pulse-width_modulation" title="Pulse-width modulation">Pulse-width modulation</a> (PWM) and pulse-depth modulation (PDM)</li>

<li><a href="Pulse-frequency_modulation" title="Pulse-frequency modulation">Pulse-frequency modulation</a> (PFM)</li>

<li><a href="Pulse-position_modulation" title="Pulse-position modulation">Pulse-position modulation</a> (PPM)</li></ul>

<dl><dt>Analog-over-digital methods</dt></dl>

<ul><li><a href="Pulse-code_modulation" title="Pulse-code modulation">Pulse-code modulation</a> (PCM)

<ul><li><a href="Differential_PCM" class="mw-redirect" title="Differential PCM">Differential PCM</a> (DPCM)

<ul><li><a href="Adaptive_DPCM" class="mw-redirect" title="Adaptive DPCM">Adaptive DPCM</a> (ADPCM)</li></ul></li></ul></li>

<li><a href="Delta_modulation" title="Delta modulation">Delta modulation</a> (DM or Δ-modulation)

<ul><li><a href="Delta-sigma_modulation" title="Delta-sigma modulation">Delta-sigma modulation</a> (ΣΔ)</li>

<li><a href="Continuously_variable_slope_delta_modulation" title="Continuously variable slope delta modulation">Continuously variable slope delta modulation</a> (CVSDM), also called <a href="Adaptive_delta_modulation" class="mw-redirect" title="Adaptive delta modulation">adaptive delta modulation</a> (ADM)</li></ul></li>

<li><a href="Pulse-density_modulation" title="Pulse-density modulation">Pulse-density modulation</a> (PDM)</li></ul>

<div class="mw-heading mw-heading2"><h2 id="Miscellaneous_modulation_techniques">Miscellaneous modulation techniques</h2></div>

<ul><li>The use of <a href="On-off_keying" class="mw-redirect" title="On-off keying">on-off keying</a> to transmit <a href="Morse_code" title="Morse code">Morse code</a> at <a href="Radio_frequencies" class="mw-redirect" title="Radio frequencies">radio frequencies</a> is known as <a href="Continuous_wave" title="Continuous wave">continuous wave</a> (CW) operation.</li>

<li><a href="Adaptive_modulation" class="mw-redirect" title="Adaptive modulation">Adaptive modulation</a></li>

<li><a href="Space_modulation" title="Space modulation">Space modulation</a> is a method whereby signals are modulated within airspace such as that used in <a href="Instrument_landing_system" title="Instrument landing system">instrument landing systems</a>.</li>

<li>The <a href="Microwave_auditory_effect" title="Microwave auditory effect">microwave auditory effect</a> has been pulse modulated with audio waveforms to evoke understandable spoken numbers.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup></li></ul>

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<div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:Modulation" class="extiw external" title="commons:Category:Modulation">Modulation</a></span>.</div></div>

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<ul><li><a href="Channel_access_method" title="Channel access method">Channel access methods</a></li>

<li><a href="Channel_coding" class="mw-redirect" title="Channel coding">Channel coding</a></li>

<li><a href="Codec" title="Codec">Codec</a></li>

<li><a href="Demodulation" title="Demodulation">Demodulation</a></li>

<li><a href="Electrical_resonance" title="Electrical resonance">Electrical resonance</a></li>

<li><a href="Heterodyne" title="Heterodyne">Heterodyne</a></li>

<li><a href="Modem" title="Modem">Modem</a></li>

<li><a href="Modulation_order" title="Modulation order">Modulation order</a></li>

<li><a href="Neuromodulation" title="Neuromodulation">Neuromodulation</a></li>

<li><a href="RF_modulator" title="RF modulator">RF modulator</a></li>

<li><a href="Ring_modulation" title="Ring modulation">Ring modulation</a></li>

<li><a href="Types_of_radio_emissions" title="Types of radio emissions">Types of radio emissions</a></li></ul>

</div>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

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</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.taitradioacademy.com/topic/how-does-modulation-work-1-1/">"How does modulation work? | Tait Radio Academy"</a>. <i>Tait Radio Academy</i>. 2014-10-22<span class="reference-accessdate">. Retrieved <span class="nowrap">2024-06-17</span></span>.</cite></span>

</li>

<li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><cite id="CITEREFHerrera2024" class="citation web cs1">Herrera, Rodrigo "Rod" (April 23, 2024). <a rel="nofollow" class="external text" href="https://www.wimo.com/en/faq/post/what-antenna-length-do-i-need-for-which-frequency">"General Antennas: What antenna length do I need for which frequency?"</a>. <i>wimo.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">June 19,</span> 2024</span>.</cite></span>

</li>

<li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.geeksforgeeks.org/computer-networks/what-is-modem/">"What is Modem?"</a>. <i>GeeksforGeeks</i>. 2023-09-11<span class="reference-accessdate">. Retrieved <span class="nowrap">2025-07-20</span></span>.</cite></span>

</li>

<li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><cite id="CITEREFTechnology2019" class="citation web cs1">Technology, Electrical (2019-01-29). <a rel="nofollow" class="external text" href="https://www.electricaltechnology.org/2019/01/types-of-modulation.html">"Types of Modulation - AM, FM, PM Modulation & Modulated Signals"</a>. <i>ELECTRICAL TECHNOLOGY</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2025-07-20</span></span>.</cite></span>

</li>

<li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.waveform.com/a/b/guides/modulation-coding-speeds">"Modulation Schemes, Coding Rates, and 4G/5G Data Speeds"</a>. <i>Waveform</i>. 2024-07-11<span class="reference-accessdate">. Retrieved <span class="nowrap">2025-07-20</span></span>.</cite></span>

</li>

<li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://documentation.meraki.com/MR/Wi-Fi_Basics_and_Best_Practices/Wireless_Fundamentals%3A_Modulation">"Wireless Fundamentals: Modulation"</a>. <i>Cisco Meraki Documentation</i>. 2020-10-05<span class="reference-accessdate">. Retrieved <span class="nowrap">2025-07-20</span></span>.</cite></span>

</li>

<li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.rohm.com/electronics-basics/wireless/wireless_what3">"Modulation Methods | Electronics Basics | ROHM"</a>. <i>www.rohm.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2025-07-20</span></span>.</cite></span>

</li>

<li id="cite_note-:0-8"><span class="mw-cite-backlink">^ <a href="#cite_ref-:0_8-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-:0_8-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-:0_8-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-:0_8-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-:0_8-4"><sup><i><b>e</b></i></sup></a></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.rohm.com/electronics-basics/wireless/wireless_what3">"Modulation Methods | Electronics Basics | ROHM"</a>. <i>www.rohm.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2025-07-20</span></span>.</cite></span>

</li>

<li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.rohm.com/electronics-basics/wireless/modulation-methods">"Modulation Methods | Electronics Basics | ROHM"</a>. <i>www.rohm.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2020-05-15</span></span>.</cite></span>

</li>

<cite id="CITEREFDobre,_Octavia_A.,_Ali_Abdi,_Yeheskel_Bar-Ness,_and_Wei_Su._Communications,_IET_1,_no._2_(2007):_137–156.2007" class="citation journal cs1">Dobre, Octavia A., Ali Abdi, Yeheskel Bar-Ness, and Wei Su. Communications, IET 1, no. 2 (2007): 137–156. (2007). <a rel="nofollow" class="external text" href="http://web.njit.edu/~abdi/IEE_COM0176_WithFigures.pdf">"Survey of automatic modulation classification techniques: classical approaches and new trends"</a> <span class="cs1-format">(PDF)</span>. <i>IET Communications</i>. <b>1</b> (2): <span class="nowrap">137–</span>156. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1049%2Fiet-com%3A20050176">10.1049/iet-com:20050176</a>.</cite><span class="cs1-maint citation-comment"><code class="cs1-code">{{cite journal}}</code>: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)</span></span>

</li>

<li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><cite id="CITEREFLin2021" class="citation book cs1">Lin, James C. (August 20, 2021). <i>Auditory Effects of Microwave Radiation</i>. Chicago: Springer. p. 326. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-3030645434</bdi>.</cite></span>

</li>

<li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><cite id="CITEREFJustesen1975" class="citation magazine cs1">Justesen, Don (March 1, 1975). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160910133313/http://www.mitchelleffect.com/1973_voice_to_skull.pdf">"Microwaves and Behavior"</a> <span class="cs1-format">(PDF)</span>. <i>American Psychologist</i>. Washington, D.C.: American Psychological Association. Archived from <a rel="nofollow" class="external text" href="http://www.mitchelleffect.com/1973_voice_to_skull.pdf">the original</a> <span class="cs1-format">(PDF)</span> on 2016-09-10<span class="reference-accessdate">. Retrieved <span class="nowrap">October 5,</span> 2021</span>.</cite></span>

</li>

<li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><cite id="CITEREFJustesen1975" class="citation magazine cs1">Justesen, Don (March 1, 1975). "Microwaves and Behavior". <i>American Psychologist</i>. Vol. 30, no. 3. Washington, D.C.: American Psychological Association. pp. <span class="nowrap">391–</span>401. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1037%2F0003-066x.30.3.391">10.1037/0003-066x.30.3.391</a>. <a href="PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/1137231">1137231</a>.</cite></span>

</li>

</ol></div></div>

<div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2></div>

<ul><li><cite id="CITEREFBryantAnalog_Devices2013" class="citation journal cs1">Bryant, James; Analog Devices (2013). <a rel="nofollow" class="external text" href="http://www.analog.com/library/analogDialogue/archives/47-06/multipliers_modulators.pdf">"Multipliers vs. Modulators"</a> <span class="cs1-format">(PDF)</span>. <i>Analog Dialogue</i>. <b>47</b> (2): 3.</cite></li></ul>

<div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2></div>

<ul><li><a rel="nofollow" class="external text" href="http://webdemo.inue.uni-stuttgart.de/webdemos/02_lectures/communication_3/soft_demapping">Interactive presentation of soft-demapping for AWGN-channel in a web-demo</a> Institute of Telecommunications, University of Stuttgart</li>

<li><a rel="nofollow" class="external text" href="http://ittrap.com/modemmodulation-and-demodulation/">Modem (Modulation and Demodulation)</a></li>

<li><a rel="nofollow" class="external text" href="https://www.ac.uma.es/~guille/codsim2.0/">CodSim 2.0: Open source Virtual Laboratory for Digital Data Communications Model</a> Department of Computer Architecture, University of Malaga. Simulates Digital line encodings and Digital Modulations. Written in HTML for any web browser.</li></ul>

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</style></div><div role="navigation" class="navbox" aria-labelledby="Telecommunications802" style="padding:3px"><table class="nowraplinks hlist mw-collapsible mw-collapsed navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div id="Telecommunications802" style="font-size:114%;margin:0 4em"><a href="Telecommunications" title="Telecommunications">Telecommunications</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="History_of_telecommunication" title="History of telecommunication">History</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Beacon#For_defensive_communications" title="Beacon">Beacon</a></li>

<li><a href="History_of_broadcasting" title="History of broadcasting">Broadcasting</a></li>

<li><a href="Cable_protection_system" title="Cable protection system">Cable protection system</a></li>

<li><a href="Cable_television" title="Cable television">Cable TV</a></li>

<li><a href="Communications_satellite#History" title="Communications satellite">Communications satellite</a></li>

<li><a href="Computer_network#History" title="Computer network">Computer network</a></li>

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<ul><li><a href="Audio_coding_format" title="Audio coding format">audio</a></li>

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<li><a href="Digital_media" title="Digital media">Digital media</a>

<ul><li><a href="Internet_video" title="Internet video">Internet video</a></li>

<li><a href="Online_video_platform" title="Online video platform">online video platform</a></li>

<li><a href="Social_media" title="Social media">social media</a></li>

<li><a href="Streaming_media" title="Streaming media">streaming</a></li></ul></li>

<li><a href="Drums_in_communication" title="Drums in communication">Drums</a></li>

<li><a href="Edholm's_law" title="Edholm's law">Edholm's law</a></li>

<li><a href="Electrical_telegraph#History" title="Electrical telegraph">Electrical telegraph</a></li>

<li><a href="Heliograph#History" title="Heliograph">Heliographs</a></li>

<li><a href="Hydraulic_telegraph#Greek_hydraulic_semaphore_system" title="Hydraulic telegraph">Hydraulic telegraph</a></li>

<li><a href="Information_Age" title="Information Age">Information Age</a></li>

<li><a href="Information_revolution" class="mw-redirect" title="Information revolution">Information revolution</a></li>

<li><a href="History_of_the_Internet" title="History of the Internet">Internet</a></li>

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<li><a href="History_of_mobile_phones" title="History of mobile phones">Mobile phone</a>

<ul><li><a href="Smartphone" title="Smartphone">Smartphone</a></li></ul></li>

<li><a href="Optical_communication" title="Optical communication">Optical telecommunication</a></li>

<li><a href="Optical_telegraph" title="Optical telegraph">Optical telegraphy</a></li>

<li><a href="Pager" title="Pager">Pager</a></li>

<li><a href="Photophone" title="Photophone">Photophone</a></li>

<li><a href="History_of_prepaid_mobile_phones" title="History of prepaid mobile phones">Prepaid mobile phone</a></li>

<li><a href="History_of_radio" title="History of radio">Radio</a></li>

<li><a href="Radiotelephone" title="Radiotelephone">Radiotelephone</a></li>

<li><a href="Communications_satellite" title="Communications satellite">Satellite communications</a></li>

<li><a href="Semaphore" title="Semaphore">Semaphore</a>

<ul><li><a href="Phryctoria" title="Phryctoria">Phryctoria</a></li></ul></li>

<li><a href="Semiconductor" title="Semiconductor">Semiconductor</a>

<ul><li><a href="Semiconductor_device" title="Semiconductor device">device</a></li>

<li><a href="MOSFET" title="MOSFET">MOSFET</a></li>

<li><a href="History_of_the_transistor" title="History of the transistor">transistor</a></li></ul></li>

<li><a href="Smoke_signal" title="Smoke signal">Smoke signals</a></li>

<li><a href="History_of_telecommunication" title="History of telecommunication">Telecommunications history</a></li>

<li><a href="Telautograph" title="Telautograph">Telautograph</a></li>

<li><a href="Telegraphy" title="Telegraphy">Telegraphy</a></li>

<li><a href="Teleprinter" title="Teleprinter">Teleprinter</a> (teletype)</li>

<li><a href="History_of_the_telephone" title="History of the telephone">Telephone</a></li>

<li><i><a href="The_Telephone_Cases" title="The Telephone Cases">The Telephone Cases</a></i></li>

<li><a href="History_of_television" title="History of television">Television</a>

<ul><li><a href="Digital_television" title="Digital television">digital</a></li>

<li><a href="Streaming_television" title="Streaming television">streaming</a></li></ul></li>

<li><a href="Submarine_communications_cable#Early_history:_telegraph_and_coaxial_cables" title="Submarine communications cable">Undersea telegraph line</a></li>

<li><a href="History_of_videotelephony" title="History of videotelephony">Videotelephony</a></li>

<li><a href="Whistled_language" title="Whistled language">Whistled language</a></li>

<li><a href="Wireless_revolution" class="mw-redirect" title="Wireless revolution">Wireless revolution</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Pioneers</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Nasir_Ahmed_(engineer)" title="Nasir Ahmed (engineer)">Nasir Ahmed</a></li>

<li><a href="Edwin_Howard_Armstrong" title="Edwin Howard Armstrong">Edwin Howard Armstrong</a></li>

<li><a href="Mohamed_M._Atalla" title="Mohamed M. Atalla">Mohamed M. Atalla</a></li>

<li><a href="John_Logie_Baird" title="John Logie Baird">John Logie Baird</a></li>

<li><a href="Paul_Baran" title="Paul Baran">Paul Baran</a></li>

<li><a href="John_Bardeen" title="John Bardeen">John Bardeen</a></li>

<li><a href="Alexander_Graham_Bell" title="Alexander Graham Bell">Alexander Graham Bell</a></li>

<li><a href="Emile_Berliner" title="Emile Berliner">Emile Berliner</a></li>

<li><a href="Tim_Berners-Lee" title="Tim Berners-Lee">Tim Berners-Lee</a></li>

<li><a href="Francis_Blake_(inventor)" title="Francis Blake (inventor)">Francis Blake</a></li>

<li><a href="Jagadish_Chandra_Bose" title="Jagadish Chandra Bose">Jagadish Chandra Bose</a></li>

<li><a href="Charles_Bourseul" title="Charles Bourseul">Charles Bourseul</a></li>

<li><a href="Walter_Houser_Brattain" class="mw-redirect" title="Walter Houser Brattain">Walter Houser Brattain</a></li>

<li><a href="Claude_Chappe" title="Claude Chappe">Claude Chappe</a></li>

<li><a href="Yogen_Dalal" class="mw-redirect" title="Yogen Dalal">Yogen Dalal</a></li>

<li><a href="Donald_Davies" title="Donald Davies">Donald Davies</a></li>

<li><a href="Daniel_Davis_Jr." title="Daniel Davis Jr.">Daniel Davis Jr.</a></li>

<li><a href="Amos_Dolbear" title="Amos Dolbear">Amos Dolbear</a></li>

<li><a href="Thomas_Edison" title="Thomas Edison">Thomas Edison</a></li>

<li><a href="Philo_Farnsworth" title="Philo Farnsworth">Philo Farnsworth</a></li>

<li><a href="Reginald_Fessenden" title="Reginald Fessenden">Reginald Fessenden</a></li>

<li><a href="Lee_de_Forest" title="Lee de Forest">Lee de Forest</a></li>

<li><a href="Elisha_Gray" title="Elisha Gray">Elisha Gray</a></li>

<li><a href="Oliver_Heaviside" title="Oliver Heaviside">Oliver Heaviside</a></li>

<li><a href="Robert_Hooke" title="Robert Hooke">Robert Hooke</a></li>

<li><a href="Erna_Schneider_Hoover" title="Erna Schneider Hoover">Erna Schneider Hoover</a></li>

<li><a href="Harold_Hopkins_(physicist)" title="Harold Hopkins (physicist)">Harold Hopkins</a></li>

<li><a href="Gardiner_Greene_Hubbard" title="Gardiner Greene Hubbard">Gardiner Greene Hubbard</a></li>

<li><a href="Dawon_Kahng" title="Dawon Kahng">Dawon Kahng</a></li>

<li><a href="Charles_K._Kao" title="Charles K. Kao">Charles K. Kao</a></li>

<li><a href="Narinder_Singh_Kapany" title="Narinder Singh Kapany">Narinder Singh Kapany</a></li>

<li><a href="Hedy_Lamarr" title="Hedy Lamarr">Hedy Lamarr</a></li>

<li><a href="Roberto_Landell_de_Moura" title="Roberto Landell de Moura">Roberto Landell</a></li>

<li><a href="Innocenzo_Manzetti" title="Innocenzo Manzetti">Innocenzo Manzetti</a></li>

<li><a href="Guglielmo_Marconi" title="Guglielmo Marconi">Guglielmo Marconi</a></li>

<li><a href="Robert_Metcalfe" title="Robert Metcalfe">Robert Metcalfe</a></li>

<li><a href="Antonio_Meucci" title="Antonio Meucci">Antonio Meucci</a></li>

<li><a href="Samuel_Morse" title="Samuel Morse">Samuel Morse</a></li>

<li><a href="Jun-ichi_Nishizawa" title="Jun-ichi Nishizawa">Jun-ichi Nishizawa</a></li>

<li><a href="Charles_Grafton_Page" title="Charles Grafton Page">Charles Grafton Page</a></li>

<li><a href="Radia_Perlman" title="Radia Perlman">Radia Perlman</a></li>

<li><a href="Alexander_Stepanovich_Popov" class="mw-redirect" title="Alexander Stepanovich Popov">Alexander Stepanovich Popov</a></li>

<li><a href="Tivadar_Pusk%C3%A1s" title="Tivadar Puskás">Tivadar Puskás</a></li>

<li><a href="Johann_Philipp_Reis" title="Johann Philipp Reis">Johann Philipp Reis</a></li>

<li><a href="Claude_Shannon" title="Claude Shannon">Claude Shannon</a></li>

<li><a href="Almon_Brown_Strowger" title="Almon Brown Strowger">Almon Brown Strowger</a></li>

<li><a href="Henry_Sutton_(inventor)" title="Henry Sutton (inventor)">Henry Sutton</a></li>

<li><a href="Charles_Sumner_Tainter" title="Charles Sumner Tainter">Charles Sumner Tainter</a></li>

<li><a href="Nikola_Tesla" title="Nikola Tesla">Nikola Tesla</a></li>

<li><a href="Camille_Tissot" title="Camille Tissot">Camille Tissot</a></li>

<li><a href="Alfred_Vail" title="Alfred Vail">Alfred Vail</a></li>

<li><a href="Thomas_A._Watson" title="Thomas A. Watson">Thomas A. Watson</a></li>

<li><a href="Charles_Wheatstone" title="Charles Wheatstone">Charles Wheatstone</a></li>

<li><a href="Vladimir_K._Zworykin" title="Vladimir K. Zworykin">Vladimir K. Zworykin</a></li>

<li><i><a href="List_of_Internet_pioneers" title="List of Internet pioneers">Internet pioneers</a></i></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Transmission_medium" title="Transmission medium">Transmission<br>media</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Coaxial_cable" title="Coaxial cable">Coaxial cable</a></li>

<li><a href="Fiber-optic_communication" title="Fiber-optic communication">Fiber-optic communication</a>

<ul><li><a href="Optical_fiber" title="Optical fiber">optical fiber</a></li></ul></li>

<li><a href="Free-space_optical_communication" title="Free-space optical communication">Free-space optical communication</a></li>

<li><a href="Molecular_communication" title="Molecular communication">Molecular communication</a></li>

<li><a href="Radio_wave" title="Radio wave">Radio waves</a>

<ul><li><a href="Wireless" title="Wireless">wireless</a></li></ul></li>

<li><a href="Transmission_line" title="Transmission line">Transmission line</a>

<ul><li><a href="Telecommunication_circuit" title="Telecommunication circuit">telecommunication circuit</a></li></ul></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Network_topology" title="Network topology">Network topology</a><br>and switching</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Bandwidth_(computing)" title="Bandwidth (computing)">Bandwidth</a></li>

<li><a href="Telecommunications_link" title="Telecommunications link">Links</a></li>

<li><a href="Network_switch" title="Network switch">Network switching</a>

<ul><li><a href="Circuit_switching" title="Circuit switching">circuit</a></li>

<li><a href="Packet_switching" title="Packet switching">packet</a></li></ul></li>

<li><a href="Node_(networking)" title="Node (networking)">Nodes</a>

<ul><li><a href="Terminal_(telecommunication)" title="Terminal (telecommunication)">terminal</a></li></ul></li>

<li><a href="Telephone_exchange" title="Telephone exchange">Telephone exchange</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Multiplexing" title="Multiplexing">Multiplexing</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Space-division_multiple_access" title="Space-division multiple access">Space-division</a></li>

<li><a href="Frequency-division_multiplexing" title="Frequency-division multiplexing">Frequency-division</a></li>

<li><a href="Time-division_multiplexing" title="Time-division multiplexing">Time-division</a></li>

<li><a href="Polarization-division_multiplexing" title="Polarization-division multiplexing">Polarization-division</a></li>

<li><a href="Orbital_angular_momentum_multiplexing" title="Orbital angular momentum multiplexing">Orbital angular-momentum</a></li>

<li><a href="Code-division_multiple_access" title="Code-division multiple access">Code-division</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Concepts</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Communication_protocol" title="Communication protocol">Communication protocol</a></li>

<li><a href="Computer_network" title="Computer network">Computer network</a></li>

<li><a href="Data_communication" title="Data communication">Data transmission</a></li>

<li><a href="Store_and_forward" title="Store and forward">Store and forward</a></li>

<li><a href="Telecommunications_equipment" title="Telecommunications equipment">Telecommunications equipment</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Telecommunications_network" title="Telecommunications network">Types of network</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Cellular_network" title="Cellular network">Cellular network</a></li>

<li><a href="Ethernet" title="Ethernet">Ethernet</a></li>

<li><a href="Mobile_telephony" title="Mobile telephony">Mobile</a></li>

<li><a href="Public_switched_telephone_network" title="Public switched telephone network">Public Switched Telephone</a></li>

<li><a href="Radio_network" title="Radio network">Radio</a></li>

<li><a href="Television_broadcasting" class="mw-redirect" title="Television broadcasting">Television</a></li>

<li><a href="Telex" title="Telex">Telex</a></li>

<li><a href="Wireless_network" title="Wireless network">Wireless network</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Telecommunications_network" title="Telecommunications network">Notable networks</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="ARPANET" title="ARPANET">ARPANET</a></li>

<li><a href="BITNET" title="BITNET">BITNET</a></li>

<li><a href="CYCLADES" title="CYCLADES">CYCLADES</a></li>

<li><a href="FidoNet" title="FidoNet">FidoNet</a></li>

<li><a href="Internet" title="Internet">Internet</a></li>

<li><a href="Internet2" title="Internet2">Internet2</a></li>

<li><a href="JANET" title="JANET">JANET</a></li>

<li><a href="NPL_network" title="NPL network">NPL network</a></li>

<li><a href="TANet" title="TANet">TANet</a></li>

<li><a href="Toasternet" title="Toasternet">Toasternet</a></li>

<li><a href="Usenet" title="Usenet">Usenet</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Locations</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li>Africa</li>

<li>Americas

<ul><li>North</li>

<li>South</li></ul></li>

<li>Antarctica</li>

<li>Europe</li>

<li>Oceania</li>

<li><i><a href="List_of_telecommunications_regulatory_bodies" title="List of telecommunications regulatory bodies">Global telecommunications regulation bodies</a></i></li></ul>

</div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div>

<ul><li><span class="nowrap"><span class="noviewer" typeof="mw:File"><span></span></span> </span><a href="Portal%3ATelecommunication" title="Portal:Telecommunication">Telecommunication portal</a></li>

<li><span class="noviewer" typeof="mw:File"><span title="Category"></span></span> Category</li>

<li><span class="noviewer" typeof="mw:File"><span title="List-Class article"></span></span> <a href="Outline_of_telecommunication" title="Outline of telecommunication">Outline</a></li>

<li><span class="noviewer" typeof="mw:File"><span title="Commons page"></span></span> <a href="https://commons.wikimedia.org/wiki/Category:Telecommunications" class="extiw external" title="commons:Category:Telecommunications">Commons</a></li></ul>

</div></td></tr></tbody></table></div>

<div class="navbox-styles"></div><div role="navigation" class="navbox" aria-labelledby="Analog_and_digital_audio_broadcasting130" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div id="Analog_and_digital_audio_broadcasting130" style="font-size:114%;margin:0 4em"><a href="Analog_recording" title="Analog recording">Analog</a> and <a href="Digital_audio" title="Digital audio">digital audio</a> <a href="Broadcasting" title="Broadcasting">broadcasting</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Terrestrial</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Radio" title="Radio">Radio</a> <a href="Modulation" class="mw-redirect" title="Modulation">modulation</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<li><a href="Orthogonal_frequency-division_multiplexing" title="Orthogonal frequency-division multiplexing">COFDM</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Frequency_allocation" title="Frequency allocation">Frequency allocations</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Digital systems</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<li><a href="FMeXtra" title="FMeXtra">FMeXtra</a></li>

<li><a href="HD_Radio" title="HD Radio">HD Radio</a></li>

</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Satellite</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Frequency allocations</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Commercial_broadcasting" title="Commercial broadcasting">Commercial radio</a> providers</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="SiriusXM" title="SiriusXM">SiriusXM</a>

<ul><li><a href="SiriusXM_Canada" title="SiriusXM Canada">Canada</a></li></ul></li></ul>

</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Audio_codec" title="Audio codec">Codecs</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<li><a href="MPEG-1_Audio_Layer_II" title="MPEG-1 Audio Layer II">MPEG-1 Audio Layer II</a></li>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Subcarrier" title="Subcarrier">Subcarrier</a> signals</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<li><a href="DirectBand" title="DirectBand">DirectBand</a></li>

</div></td></tr><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div id="Related_topics252" style="font-size:114%;margin:0 4em">Related topics</div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Technical (audio)</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Audio_data_compression" class="mw-redirect" title="Audio data compression">Audio data compression</a></li>

<li><a href="Audio_signal_processing" title="Audio signal processing">Audio signal processing</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Technical (<a href="AM_stereo" title="AM stereo">AM stereo</a> formats)</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="AM_stereo#Belar_System" title="AM stereo">Belar</a></li>

<li><a href="AM_stereo#Harris_System" title="AM stereo">Harris</a></li>

<li><a href="AM_stereo#Kahn-Hazeltine" title="AM stereo">Kahn-Hazeltine</a></li>

<li><a href="AM_stereo#Magnavox_System" title="AM stereo">Magnavox</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Technical (emission)</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="AM_broadcasting" title="AM broadcasting">AM broadcasting</a></li>

<li><a href="AM_expanded_band" title="AM expanded band">AM expanded band</a></li>

<li><a href="Cable_radio" title="Cable radio">Cable radio</a></li>

<li><a href="Digital_radio" title="Digital radio">Digital radio</a></li>

<li><a href="Error_detection_and_correction" title="Error detection and correction">Error detection and correction</a></li>

<li><a href="FM_broadcast_band" title="FM broadcast band">FM broadcast band</a></li>

<li><a href="FM_broadcasting" title="FM broadcasting">FM broadcasting</a></li>

<li><a href="FM_extended_band_in_Brazil" title="FM extended band in Brazil">FM extended band in Brazil</a></li>

<li><a href="Multipath_propagation" title="Multipath propagation">Multipath propagation</a></li>

<li><a href="Shortwave_relay_station" title="Shortwave relay station">Shortwave relay station</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Cultural</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="History_of_radio" title="History of radio">History of radio</a></li>

<li><a href="International_broadcasting" title="International broadcasting">International broadcasting</a></li></ul>

</div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div>

<ul><li><b><span class="nowrap"><span class="noviewer" typeof="mw:File"><span></span></span> </span><a href="Portal%3ARadio" title="Portal:Radio">Radio portal</a></b></li>

<li><a href="Comparison_of_radio_systems" title="Comparison of radio systems">Comparison of radio systems</a></li></ul>

</div></td></tr></tbody></table><div></div></td></tr></tbody></table></div>

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</style></div><div role="navigation" class="navbox authority-control" aria-labelledby="Authority_control_databases_frameless&#124;text-top&#124;10px&#124;alt=Edit_this_at_Wikidata&#124;link=https&#58;//www.wikidata.org/wiki/Q170474#identifiers&#124;class=noprint&#124;Edit_this_at_Wikidata1194" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div id="Authority_control_databases_frameless&#124;text-top&#124;10px&#124;alt=Edit_this_at_Wikidata&#124;link=https&#58;//www.wikidata.org/wiki/Q170474#identifiers&#124;class=noprint&#124;Edit_this_at_Wikidata1194" style="font-size:114%;margin:0 4em">Authority control databases </div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">National</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><a rel="nofollow" class="external text" href="https://d-nb.info/gnd/4039849-3">Germany</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://id.loc.gov/authorities/sh85086466">United States</a></span></li><li><span class="uid"><span class="rt-commentedText tooltip tooltip-dotted" title="Modulation (électronique)"><a rel="nofollow" class="external text" href="https://catalogue.bnf.fr/ark:/12148/cb11941892m">France</a></span></span></li><li><span class="uid"><span class="rt-commentedText tooltip tooltip-dotted" title="Modulation (électronique)"><a rel="nofollow" class="external text" href="https://data.bnf.fr/ark:/12148/cb11941892m">BnF data</a></span></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://www.nli.org.il/en/authorities/987007541016105171">Israel</a></span></li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><a rel="nofollow" class="external text" href="https://lux.collections.yale.edu/view/concept/23b6f612-f83c-4d7c-bcf8-c4b88f303672">Yale LUX</a></span></li></ul></div></td></tr></tbody></table></div></div><div><div class="zim-footer">

This article is issued from <a class="external text" title="Last edited on 2025-07-31" href="https://en.wikipedia.org/wiki/?title=Signal_modulation&oldid=1303559644">Wikipedia</a>. The text is available under <a class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en">Creative Commons Attribution-Share Alike 4.0</a> unless otherwise noted. Additional terms may apply for the media files.

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