1463:. 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.
1404:(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
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1459:. 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
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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
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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
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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
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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
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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
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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
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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
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has been adjusted to around 2.4, so the carrier frequency has small amplitude. Several strong sidebands are apparent; in principle an infinite number are produced in FM but the higher-order sidebands are of negligible
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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.
506:, 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
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with length that is one-fourth of wavelength. For low frequency radio waves, wavelength is on the scale of kilometers and building such a large antenna is not practical. In
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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
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of a 146.52 MHz radio carrier, with amplitude modulation by a 1,000 Hz sinusoid. Two strong sidebands at + and - 1 kHz from the carrier frequency are shown.
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all digital communication systems, both the modulator at the transmitter and the demodulator at the receiver are structured so that they perform inverse operations.
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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
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1394:(CPFSK) which is defined by a rectangular frequency pulse (i.e. a linearly increasing phase pulse) of one-symbol-time duration (total response signaling).
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Department of
Computer Architecture, University of Malaga. Simulates Digital line encodings and Digital Modulations. Written in HTML for any web browser.
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odulator), used in bidirectional communication, can perform both operations. The lower frequency band occupied by the modulation signal is called the
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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.
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of the same output power. However, they only work with relatively constant-amplitude-modulation signals such as angle modulation (FSK or PSK) and
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or some other filtering to limit the bandwidth and form the spectrum of the equivalent low pass signal, typically using digital signal processing.
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Map the codewords to attributes, for example, amplitudes of the I and Q signals (the equivalent low pass signal), or frequency or phase values.
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Pulse modulation schemes aim at transferring a narrowband analog signal over an analog baseband channel as a two-level signal by modulating a
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or detection as analog-to-digital conversion. The changes in the carrier signal are chosen from a finite number of M alternative symbols (the
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modulation, the modulation is applied continuously in response to the analog information signal. Common analog modulation techniques include:
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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
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This article is about the method to imprint data on a carrier used in communications and electrical engineering. For other uses, see
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than the message signal does. This is because it is impractical to transmit signals with low frequencies. Generally, to receive a
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Digital baseband modulation changes the characteristics of a baseband signal, i.e., one without a carrier at a higher frequency.
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of the carrier wave is varied by the modulation signal. These were the earliest types of modulation, and are used to transmit an
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Perform digital to analog conversion (DAC) of the I and Q signals (since today all of the above is normally achieved using
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Another purpose of modulation is to transmit multiple channels of information through a single communication medium, using
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1502:. Some pulse modulation schemes also allow the narrowband analog signal to be transferred as a digital signal (i.e., as a
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Sampling and analog-to-digital conversion (ADC) (sometimes before or instead of the above point, for example by means of
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are particular cases of continuous phase modulation. Indeed, MSK is a particular case of the sub-family of CPM known as
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Automatic digital modulation recognition in intelligent communication systems is one of the most important issues in
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to a carrier frequency, or for direct communication in baseband. The latter methods both involve relatively simple
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Dobre, Octavia A., Ali Abdi, Yeheskel Bar-Ness, and Wei Su. Communications, IET 1, no. 2 (2007): 137–156. (2007).
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In all of the above methods, each of these phases, frequencies or amplitudes are assigned a unique pattern of
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Pass the resultant bit stream on for further processing such as removal of any error-correcting codes.
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that typically contains information to be transmitted. For example, the modulation signal might be an
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2054:. Vol. 30, no. 3. Washington, D.C.: American Psychological Association. pp. 391–401.
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1934:"Survey of automatic modulation classification techniques: classical approaches and new trends"
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Detection of the amplitudes of the I and Q signals, or the frequency or phase of the IF signal.
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Amplification and analog bandpass filtering to avoid harmonic distortion and periodic spectrum.
618:(FSK) modulation. A more complicated digital modulation method that employs multiple carriers,
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has been pulse modulated with audio waveforms to evoke understandable spoken numbers.
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Mapping of the quantized amplitudes, frequencies or phases to codewords (bit groups).
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CodSim 2.0: Open source
Virtual Laboratory for Digital Data Communications Model
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1513:. These are not modulation schemes in the conventional sense since they are not
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is a method whereby signals are modulated within airspace such as that used in
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Asynchronous methods do not require a receiver reference clock signal that is
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A low-frequency message signal (top) may be carried by an AM or FM radio wave.
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or RF signal. Sometimes this is achieved using DSP technology, for example
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Schematic of 4 baud, 8 bit/s data link containing arbitrarily chosen values
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Interactive presentation of soft-demapping for AWGN-channel in a web-demo
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817:. Most textbooks would consider digital modulation schemes as a form of
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502:(which uses FDM), many carrier signals, each modulated with a different
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578:(strength) of the carrier wave is varied by the modulation signal, and
2020:. Washington, D.C.: American Psychological Association. Archived from
1884:"General Antennas: What antenna length do I need for which frequency?"
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that is represented by the particular phase, frequency or amplitude.
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schemes, and in some cases analog-to-digital conversion techniques.
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alternative symbols, each symbol represents a message consisting of
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Categorization for signal modulation based on data and carrier types
1371:(CSS) according to IEEE 802.15.4a CSS uses pseudo-stochastic coding
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Parallel-to-serial conversion of the codewords into a bit stream.
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Single-sideband modulation suppressed carrier modulation (SSB-SC)
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The most fundamental digital modulation techniques are based on
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A carrier, frequency modulated by a 1,000 Hz sinusoid. The
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Process of varying one or more properties of a periodic waveform
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is the process of varying one or more properties of a periodic
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modulation signal is "impressed" on the carrier. Examples are
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signal is equivalent to a combination of PSK and ASK.
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to extract the information bearing modulation signal.
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is twice the symbol rate, i.e. 2000 bits per second.
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stations and digital cable television transmission.
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1776:. Unsourced material may be challenged and removed.
1377:(FHSS) applies a special scheme for channel release
1198:The most common digital modulation techniques are:
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may be too technical for most readers to understand
1478:This can be used as equivalent signal to be later
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952:
913:
1909:"Modulation Methods | Electronics Basics | ROHM"
1858:"How does modulation work? | Tait Radio Academy"
710:Single-sideband modulation with carrier (SSB-WC)
1447:Automatic digital modulation recognition (ADMR)
691:Double-sideband suppressed-carrier transmission
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1008:Modulator and detector principles of operation
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1410:orthogonal frequency-division multiple access
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8:
1965:: CS1 maint: multiple names: authors list (
1596:Continuously variable slope delta modulation
1435:) cost less and use less battery power than
1194:List of common digital modulation techniques
697:Double-sideband reduced carrier transmission
467:This carrier wave usually has a much higher
460:representing a sequence of binary digits, a
3152:Global telecommunications regulation bodies
1414:multi-carrier code-division multiple access
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1969:) CS1 maint: numeric names: authors list (
1329:Orthogonal frequency-division multiplexing
1040:is a complex-valued representation of the
854:: a finite number of frequencies are used.
620:orthogonal frequency-division multiplexing
390:
376:
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1882:Herrera, Rodrigo "Rod" (April 23, 2024).
1836:Learn how and when to remove this message
1044:modulated physical signal (the so-called
978:
969:
944:
938:
905:
893:
860:: a finite number of amplitudes are used.
80:Learn how and when to remove this message
64:, without removing the technical details.
1211:Quadrature PSK (QPSK), using M=4 symbols
1055:These are the general steps used by the
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1986:Auditory Effects of Microwave Radiation
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1392:continuous-phase frequency-shift keying
1321:Continuous-phase frequency-shift keying
1143:Equalization filtering, for example, a
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1958:
1539:(PWM) and pulse-depth modulation (PDM)
833:Fundamental digital modulation methods
1517:schemes, but should be considered as
1297:like QAM a combination of PSK and ASK
864:QAM (quadrature amplitude modulation)
848:: a finite number of phases are used.
62:make it understandable to non-experts
7:
3198:
1774:adding citations to reliable sources
1291:(QAM), a combination of PSK and ASK
1208:Binary PSK (BPSK), using M=2 symbols
432:, with a separate signal called the
2111:Modem (Modulation and Demodulation)
1615:Miscellaneous modulation techniques
1988:. Chicago: Springer. p. 326.
452:representing moving images from a
25:
1984:Lin, James C. (August 20, 2021).
1375:Frequency-hopping spread spectrum
684:Double-sideband modulation (DSB)
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2787:Free-space optical communication
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1273:(OOK), the most common ASK form
825:; very few would consider it as
797:is 1000 symbols/second, or 1000
590:representing sound in AM and FM
105:
41:
2046:Justesen, Don (March 1, 1975).
2009:Justesen, Don (March 1, 1975).
1761:needs additional citations for
1402:frequency-division multiplexing
1363:Direct-sequence spread spectrum
1289:Quadrature amplitude modulation
809:According to one definition of
725:Quadrature amplitude modulation
535:, the inverse of modulation. A
496:frequency-division multiplexing
3710:Error detection and correction
1:
1315:Gaussian minimum-shift keying
1278:vestigial sideband modulation
1186:transferred. The opposite is
719:Vestigial sideband modulation
531:) is a circuit that performs
3173:Telecommunication portal
2954:Telecommunications equipment
1251:Multi-frequency shift keying
1245:Audio frequency-shift keying
888:If the alphabet consists of
858:ASK (amplitude-shift keying)
852:FSK (frequency-shift keying)
815:digital-to-analog conversion
602:consisting of a sequence of
521:that performs modulation. A
3783:Comparison of radio systems
2690:Alexander Stepanovich Popov
1556:Analog-over-digital methods
1471:Digital baseband modulation
1303:Continuous phase modulation
1032:). The resulting so called
32:Modulation (disambiguation)
3854:
3756:International broadcasting
3725:FM extended band in Brazil
2394:Telecommunications history
2094:Analog Dialogue, June 2013
2092:Multipliers vs. Modulators
2060:10.1037/0003-066x.30.3.391
1649:instrument landing systems
1543:Pulse-frequency modulation
1531:Pulse-amplitude modulation
1525:Analog-over-analog methods
1103:At the receiver side, the
1038:equivalent baseband signal
761:Digital modulation methods
705:Single-sideband modulation
594:. More recent systems use
299:Capacity-approaching codes
29:
3764:
3610:
3161:
3002:Public Switched Telephone
2814:telecommunication circuit
2775:Fiber-optic communication
2520:Francis Blake (telephone)
2315:Optical telecommunication
2048:"Microwaves and Behavior"
2011:"Microwaves and Behavior"
1656:microwave auditory effect
1600:adaptive delta modulation
1549:Pulse-position modulation
1257:Dual-tone multi-frequency
1223:Differential QPSK (DQPSK)
1217:16PSK, using M=16 symbols
1117:, AGC (to compensate for
1078:digital signal processing
1034:equivalent lowpass signal
735:, which is approximately
634:Analog modulation methods
3833:Telecommunication theory
3823:Physical layer protocols
2913:Orbital angular-momentum
2350:Satellite communications
2189:Communications satellite
1953:10.1049/iet-com:20050176
1735:Types of radio emissions
1608:Pulse-density modulation
1494:Pulse modulation methods
1400:is based on the idea of
1348:Trellis coded modulation
1149:intersymbol interference
1131:superheterodyne receiver
1090:direct digital synthesis
846:PSK (phase-shift keying)
3735:Shortwave relay station
3634:Audio signal processing
2792:Molecular communication
2615:Gardiner Greene Hubbard
2444:Undersea telegraph line
2179:Cable protection system
1220:Differential PSK (DPSK)
1214:8PSK, using M=8 symbols
914:{\displaystyle M=2^{N}}
498:(FDM). For example, in
236:Hierarchical modulation
3838:Television terminology
3828:Radio modulation modes
3629:Audio data compression
2934:Communication protocol
2720:Charles Sumner Tainter
2535:Walter Houser Brattain
2480:Edwin Howard Armstrong
2288:Information revolution
1685:Communications channel
1670:Channel access methods
1590:Delta-sigma modulation
1537:Pulse-width modulation
1461:software-defined radio
1453:software-defined radio
1265:Amplitude-shift keying
1239:Frequency-shift keying
1188:synchronous modulation
1151:and symbol distortion.
1115:Automatic gain control
988:
987:{\displaystyle Nf_{S}}
954:
915:
807:
785:
667:
654:
643:
616:frequency-shift keying
407:
3818:Television technology
3730:Multipath propagation
3553:MPEG-1 Audio Layer II
3423:Frequency allocations
3298:Frequency allocations
2908:Polarization-division
2640:Narinder Singh Kapany
2605:Erna Schneider Hoover
2525:Jagadish Chandra Bose
2505:Alexander Graham Bell
2236:online video platform
2052:American Psychologist
2018:American Psychologist
1598:(CVSDM), also called
1586:(DM or Δ-modulation)
1562:Pulse-code modulation
1406:channel access method
1369:Chirp spread spectrum
1350:(TCM), also known as
1002:constellation diagram
989:
955:
953:{\displaystyle f_{S}}
916:
787:
783:
660:
649:
641:
405:
3683:Technical (emission)
2750:Vladimir K. Zworykin
2710:Almon Brown Strowger
2680:Charles Grafton Page
2335:Prepaid mobile phone
2263:Electrical telegraph
1770:improve this article
1695:Electrical resonance
1507:discrete-time signal
1429:switching amplifiers
1423:Of the two kinds of
1420:to different users.
1309:Minimum-shift keying
1107:typically performs:
968:
964:), the data rate is
937:
892:
819:digital transmission
742:Frequency modulation
679:Amplitude modulation
598:, which impresses a
580:frequency modulation
572:amplitude modulation
2700:Johann Philipp Reis
2459:Wireless revolution
2421:The Telephone Cases
2278:Hydraulic telegraph
1640:Adaptive modulation
1480:frequency-converted
1253:(M-ary FSK or MFSK)
1111:Bandpass filtering.
960:symbols/second (or
929:(also known as the
827:analog transmission
775:modulation alphabet
622:(OFDM), is used in
481:radio communication
2898:Frequency-division
2875:Telephone exchange
2745:Charles Wheatstone
2675:Jun-ichi Nishizawa
2650:Innocenzo Manzetti
2585:Reginald Fessenden
2320:Optical telegraphy
2153:Telecommunications
1941:IET Communications
1862:Tait Radio Academy
1433:Class D amplifiers
1425:RF power amplifier
1352:Trellis modulation
1343:Wavelet modulation
1335:Discrete multitone
1331:(OFDM) modulation
1203:Phase-shift keying
1176:phase synchronized
1059:to transmit data:
984:
950:
911:
786:
668:
655:
644:
596:digital modulation
592:radio broadcasting
582:(FM) in which the
574:(AM) in which the
504:television channel
464:from a computer.
416:telecommunications
408:
158:Digital modulation
3795:
3794:
3791:
3790:
3715:FM broadcast band
3622:Technical (audio)
3519:
3518:
3411:
3410:
3211:
3210:
2949:Store and forward
2944:Data transmission
2858:Network switching
2809:Transmission line
2655:Guglielmo Marconi
2620:Internet pioneers
2485:Mohamed M. Atalla
2454:Whistled language
1846:
1845:
1838:
1820:
1630:radio frequencies
1437:linear amplifiers
823:data transmission
790:A simple example:
737:constant envelope
707:(SSB, or SSB-AM)
564:analog modulation
434:modulation signal
400:
399:
115:Analog modulation
90:
89:
82:
16:(Redirected from
3845:
3813:Radio technology
3808:Frequency mixers
3777:Radio portal
3775:
3774:
3773:
3751:History of radio
3695:AM expanded band
3612:
3495:Commercial radio
3420:
3263:
3238:
3231:
3224:
3215:
3201:
3200:
3191:
3190:
3181:
3180:
3171:
3170:
3169:
3042:Notable networks
3032:Wireless network
2972:Cellular network
2964:Types of network
2939:Computer network
2826:Network topology
2740:Thomas A. Watson
2595:Oliver Heaviside
2580:Philo Farnsworth
2555:Daniel Davis Jr.
2530:Charles Bourseul
2490:John Logie Baird
2199:Data compression
2194:Computer network
2146:
2139:
2132:
2123:
2079:
2078:
2076:
2074:
2043:
2037:
2036:
2034:
2032:
2026:
2015:
2006:
2000:
1999:
1981:
1975:
1974:
1964:
1956:
1938:
1929:
1923:
1922:
1920:
1919:
1905:
1899:
1898:
1896:
1894:
1879:
1873:
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1870:
1869:
1854:
1841:
1834:
1830:
1827:
1821:
1819:
1778:
1754:
1746:
1715:Modulation order
1645:Space modulation
1584:Delta modulation
1568:Differential PCM
1295:Polar modulation
1178:with the sender
993:
991:
990:
985:
983:
982:
959:
957:
956:
951:
949:
948:
920:
918:
917:
912:
910:
909:
821:, synonymous to
748:Phase modulation
733:Angle modulation
721:(VSB, or VSB-AM)
663:modulation index
500:cable television
392:
385:
378:
109:
92:
85:
78:
74:
71:
65:
45:
44:
37:
21:
3853:
3852:
3848:
3847:
3846:
3844:
3843:
3842:
3798:
3797:
3796:
3787:
3771:
3769:
3760:
3739:
3720:FM broadcasting
3690:AM broadcasting
3678:
3638:
3617:
3606:
3562:
3515:
3489:
3458:Digital systems
3453:
3438:
3407:
3368:Digital systems
3363:
3292:
3254:
3242:
3212:
3207:
3167:
3165:
3157:
3099:
3036:
2958:
2922:
2879:
2828:
2820:
2761:
2754:
2660:Robert Metcalfe
2515:Tim Berners-Lee
2463:
2283:Information Age
2155:
2150:
2101:
2088:
2086:Further reading
2083:
2082:
2072:
2070:
2045:
2044:
2040:
2030:
2028:
2024:
2013:
2008:
2007:
2003:
1996:
1983:
1982:
1978:
1957:
1936:
1931:
1930:
1926:
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1915:
1907:
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1851:
1842:
1831:
1825:
1822:
1779:
1777:
1767:
1755:
1744:
1739:
1730:Ring modulation
1720:Neuromodulation
1665:
1636:(CW) operation.
1634:continuous wave
1617:
1496:
1473:
1457:cognitive radio
1449:
1418:spreading codes
1357:Spread spectrum
1196:
1086:passband signal
1046:passband signal
1010:
974:
966:
965:
940:
935:
934:
901:
890:
889:
835:
763:
636:
612:complex numbers
517:is a device or
396:
259:Spread spectrum
86:
75:
69:
66:
58:help improve it
55:
46:
42:
35:
28:
23:
22:
15:
12:
11:
5:
3851:
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3680:
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3677:
3676:
3671:
3669:Kahn-Hazeltine
3666:
3661:
3656:
3650:
3648:
3640:
3639:
3637:
3636:
3631:
3625:
3623:
3619:
3618:
3616:Related topics
3615:
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3599:
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3573:
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2936:
2930:
2928:
2924:
2923:
2921:
2920:
2915:
2910:
2905:
2900:
2895:
2893:Space-division
2889:
2887:
2881:
2880:
2878:
2877:
2872:
2871:
2870:
2865:
2855:
2854:
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2782:
2772:
2766:
2764:
2756:
2755:
2753:
2752:
2747:
2742:
2737:
2732:
2730:Camille Tissot
2727:
2722:
2717:
2712:
2707:
2705:Claude Shannon
2702:
2697:
2695:Tivadar Puskás
2692:
2687:
2682:
2677:
2672:
2667:
2665:Antonio Meucci
2662:
2657:
2652:
2647:
2642:
2637:
2635:Charles K. Kao
2632:
2627:
2622:
2617:
2612:
2610:Harold Hopkins
2607:
2602:
2597:
2592:
2587:
2582:
2577:
2572:
2567:
2562:
2557:
2552:
2547:
2542:
2537:
2532:
2527:
2522:
2517:
2512:
2510:Emile Berliner
2507:
2502:
2497:
2492:
2487:
2482:
2477:
2471:
2469:
2465:
2464:
2462:
2461:
2456:
2451:
2449:Videotelephony
2446:
2441:
2440:
2439:
2434:
2424:
2417:
2412:
2406:
2401:
2396:
2391:
2386:
2385:
2384:
2379:
2374:
2364:
2363:
2362:
2352:
2347:
2345:Radiotelephone
2342:
2337:
2332:
2327:
2322:
2317:
2312:
2311:
2310:
2300:
2295:
2290:
2285:
2280:
2275:
2270:
2265:
2260:
2255:
2250:
2249:
2248:
2243:
2238:
2233:
2231:Internet video
2223:
2222:
2221:
2216:
2211:
2206:
2196:
2191:
2186:
2181:
2176:
2171:
2165:
2163:
2157:
2156:
2151:
2149:
2148:
2141:
2134:
2126:
2120:
2119:
2113:
2108:
2100:
2099:External links
2097:
2096:
2095:
2087:
2084:
2081:
2080:
2038:
2001:
1995:978-3030645434
1994:
1976:
1947:(2): 137–156.
1924:
1900:
1874:
1848:
1847:
1844:
1843:
1758:
1756:
1749:
1743:
1740:
1738:
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1732:
1727:
1722:
1717:
1712:
1707:
1702:
1697:
1692:
1687:
1682:
1677:
1675:Channel coding
1672:
1666:
1664:
1661:
1660:
1659:
1652:
1642:
1637:
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1558:
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1552:
1546:
1540:
1534:
1527:
1526:
1515:channel coding
1495:
1492:
1472:
1469:
1448:
1445:
1381:
1380:
1379:
1378:
1372:
1366:
1354:
1345:
1340:
1339:
1338:
1326:
1325:
1324:
1318:
1312:
1305:(CPM) methods
1300:
1299:
1298:
1286:
1285:
1284:
1280:, for example
1268:
1262:
1261:
1260:
1254:
1248:
1236:
1235:
1234:
1231:
1224:
1221:
1218:
1215:
1212:
1209:
1195:
1192:
1184:asynchronously
1180:carrier signal
1168:
1167:
1164:
1161:
1158:
1155:
1152:
1145:matched filter
1141:
1134:
1126:
1121:, for example
1112:
1101:
1100:
1097:
1094:waveform table
1081:
1074:
1067:
1064:
1030:imaginary unit
1014:complex-valued
1009:
1006:
981:
977:
973:
947:
943:
908:
904:
900:
897:
868:
867:
861:
855:
849:
834:
831:
811:digital signal
762:
759:
758:
757:
756:
755:
751:
745:
730:
729:
728:
722:
716:
715:
714:
711:
702:
701:
700:
694:
688:
651:Waterfall plot
635:
632:
600:digital signal
489:radio receiver
458:digital signal
429:carrier signal
398:
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387:
380:
372:
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3711:
3708:
3706:
3705:Digital radio
3703:
3701:
3698:
3696:
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3691:
3688:
3687:
3685:
3681:
3675:
3672:
3670:
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3349:
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3307:
3304:
3303:
3301:
3299:
3295:
3289:
3286:
3284:
3281:
3279:
3276:
3275:
3273:
3271:
3268:
3264:
3261:
3257:
3253:
3250:
3249:digital audio
3246:
3239:
3234:
3232:
3227:
3225:
3220:
3219:
3216:
3204:
3196:
3194:
3186:
3184:
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3129:
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3117:
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3114:
3112:
3109:
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3020:
3018:
3015:
3013:
3010:
3008:
3005:
3003:
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2980:
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2950:
2947:
2945:
2942:
2940:
2937:
2935:
2932:
2931:
2929:
2925:
2919:
2918:Code-division
2916:
2914:
2911:
2909:
2906:
2904:
2903:Time-division
2901:
2899:
2896:
2894:
2891:
2890:
2888:
2886:
2882:
2876:
2873:
2869:
2866:
2864:
2861:
2860:
2859:
2856:
2852:
2849:
2848:
2847:
2844:
2842:
2839:
2837:
2834:
2833:
2831:
2829:and switching
2827:
2823:
2815:
2812:
2811:
2810:
2807:
2803:
2800:
2799:
2798:
2795:
2793:
2790:
2788:
2785:
2781:
2780:optical fiber
2778:
2777:
2776:
2773:
2771:
2770:Coaxial cable
2768:
2767:
2765:
2763:
2757:
2751:
2748:
2746:
2743:
2741:
2738:
2736:
2733:
2731:
2728:
2726:
2723:
2721:
2718:
2716:
2713:
2711:
2708:
2706:
2703:
2701:
2698:
2696:
2693:
2691:
2688:
2686:
2685:Radia Perlman
2683:
2681:
2678:
2676:
2673:
2671:
2668:
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2663:
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2656:
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2638:
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2618:
2616:
2613:
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2608:
2606:
2603:
2601:
2598:
2596:
2593:
2591:
2588:
2586:
2583:
2581:
2578:
2576:
2575:Lee de Forest
2573:
2571:
2570:Thomas Edison
2568:
2566:
2563:
2561:
2560:Donald Davies
2558:
2556:
2553:
2551:
2548:
2546:
2545:Claude Chappe
2543:
2541:
2538:
2536:
2533:
2531:
2528:
2526:
2523:
2521:
2518:
2516:
2513:
2511:
2508:
2506:
2503:
2501:
2498:
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2481:
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2473:
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2466:
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2438:
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2429:
2428:
2425:
2423:
2422:
2418:
2416:
2413:
2410:
2407:
2405:
2402:
2400:
2397:
2395:
2392:
2390:
2389:Smoke signals
2387:
2383:
2380:
2378:
2375:
2373:
2370:
2369:
2368:
2367:Semiconductor
2365:
2361:
2358:
2357:
2356:
2353:
2351:
2348:
2346:
2343:
2341:
2338:
2336:
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2256:
2254:
2251:
2247:
2244:
2242:
2239:
2237:
2234:
2232:
2229:
2228:
2227:
2226:Digital media
2224:
2220:
2217:
2215:
2212:
2210:
2207:
2205:
2202:
2201:
2200:
2197:
2195:
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2190:
2187:
2185:
2182:
2180:
2177:
2175:
2172:
2170:
2167:
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2162:
2158:
2154:
2147:
2142:
2140:
2135:
2133:
2128:
2127:
2124:
2117:
2114:
2112:
2109:
2106:
2103:
2102:
2098:
2093:
2090:
2089:
2085:
2069:
2065:
2061:
2057:
2053:
2049:
2042:
2039:
2027:on 2016-09-10
2023:
2019:
2012:
2005:
2002:
1997:
1991:
1987:
1980:
1977:
1972:
1968:
1962:
1954:
1950:
1946:
1942:
1935:
1928:
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1914:
1910:
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1901:
1889:
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1829:
1818:
1815:
1811:
1808:
1804:
1801:
1797:
1794:
1790:
1787: –
1786:
1782:
1781:Find sources:
1775:
1771:
1765:
1764:
1759:This article
1757:
1753:
1748:
1747:
1741:
1736:
1733:
1731:
1728:
1726:
1723:
1721:
1718:
1716:
1713:
1711:
1708:
1706:
1703:
1701:
1698:
1696:
1693:
1691:
1688:
1686:
1683:
1681:
1678:
1676:
1673:
1671:
1668:
1667:
1662:
1657:
1653:
1650:
1646:
1643:
1641:
1638:
1635:
1631:
1627:
1623:
1622:on-off keying
1619:
1618:
1614:
1609:
1606:
1601:
1597:
1594:
1591:
1588:
1587:
1585:
1582:
1575:
1574:Adaptive DPCM
1572:
1571:
1569:
1566:
1565:
1563:
1560:
1559:
1555:
1554:
1550:
1547:
1544:
1541:
1538:
1535:
1532:
1529:
1528:
1524:
1523:
1522:
1520:
1519:source coding
1516:
1512:
1508:
1505:
1501:
1493:
1491:
1489:
1485:
1481:
1476:
1470:
1468:
1464:
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1444:
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1322:
1319:
1316:
1313:
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1306:
1304:
1301:
1296:
1293:
1292:
1290:
1287:
1283:
1279:
1275:
1274:
1272:
1271:On-off keying
1269:
1266:
1263:
1258:
1255:
1252:
1249:
1246:
1243:
1242:
1240:
1237:
1232:
1229:
1226:Offset QPSK (
1225:
1222:
1219:
1216:
1213:
1210:
1207:
1206:
1204:
1201:
1200:
1199:
1193:
1191:
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1177:
1172:
1165:
1162:
1159:
1156:
1153:
1150:
1146:
1142:
1139:
1138:undersampling
1135:
1132:
1127:
1124:
1120:
1116:
1113:
1110:
1109:
1108:
1106:
1098:
1095:
1091:
1087:
1082:
1079:
1075:
1072:
1071:pulse shaping
1068:
1065:
1062:
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1058:
1053:
1051:
1047:
1043:
1039:
1035:
1031:
1027:
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1019:
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1007:
1005:
1003:
998:
995:
979:
975:
971:
963:
945:
941:
932:
928:
925:bits. If the
924:
906:
902:
898:
895:
886:
884:
880:
877:
872:
865:
862:
859:
856:
853:
850:
847:
844:
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842:
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796:
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782:
778:
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772:
768:
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752:
749:
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740:
739:
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726:
723:
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717:
712:
709:
708:
706:
703:
698:
695:
692:
689:
686:
685:
683:
682:
680:
677:
676:
675:
673:
664:
659:
652:
648:
640:
633:
631:
629:
628:digital radio
625:
621:
617:
613:
609:
605:
604:binary digits
601:
597:
593:
589:
585:
581:
577:
573:
569:
565:
560:
558:
557:
552:
551:
546:
542:
538:
534:
530:
529:
524:
520:
516:
511:
509:
505:
501:
497:
492:
490:
486:
482:
478:
477:radio antenna
474:
470:
465:
463:
459:
455:
451:
447:
443:
440:representing
439:
435:
431:
430:
426:, called the
425:
421:
417:
413:
404:
393:
388:
386:
381:
379:
374:
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370:
365:
362:
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312:
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127:
125:
122:
121:
120:
119:
116:
112:
108:
104:
103:
100:
97:
93:
84:
81:
73:
70:February 2017
63:
59:
53:
50:This article
48:
39:
38:
33:
19:
3768:
3269:
3252:broadcasting
2885:Multiplexing
2760:Transmission
2725:Nikola Tesla
2715:Henry Sutton
2670:Samuel Morse
2600:Robert Hooke
2565:Amos Dolbear
2500:John Bardeen
2419:
2399:Telautograph
2303:Mobile phone
2258:Edholm's law
2241:social media
2174:Broadcasting
2071:. Retrieved
2051:
2041:
2029:. Retrieved
2022:the original
2017:
2004:
1985:
1979:
1961:cite journal
1944:
1940:
1927:
1916:. Retrieved
1913:www.rohm.com
1912:
1903:
1891:. Retrieved
1887:
1877:
1866:. Retrieved
1864:. 2014-10-22
1861:
1852:
1832:
1823:
1813:
1806:
1799:
1792:
1785:"Modulation"
1780:
1768:Please help
1763:verification
1760:
1725:RF modulator
1690:Demodulation
1632:is known as
1624:to transmit
1497:
1477:
1474:
1465:
1450:
1422:
1412:(OFDMA) and
1396:
1382:
1197:
1173:
1169:
1102:
1054:
1025:
1021:
1017:
1011:
999:
996:
994:bit/second.
922:
887:
882:
873:
869:
836:
808:
789:
788:
774:
771:demodulation
764:
669:
595:
588:audio signal
563:
561:
554:
548:
544:
540:
533:demodulation
526:
522:
514:
512:
493:
475:one needs a
466:
454:video camera
450:video signal
438:audio signal
433:
427:
419:
409:
364:Multiplexing
304:Demodulation
98:
76:
67:
51:
3700:Cable radio
3643:Technical (
3403:DVB-T2 Lite
3259:Terrestrial
3085:NPL network
2797:Radio waves
2735:Alfred Vail
2645:Hedy Lamarr
2630:Dawon Kahng
2590:Elisha Gray
2550:Yogen Dalal
2475:Nasir Ahmed
2409:Teleprinter
2273:Heliographs
2073:October 15,
1620:The use of
1359:techniques
1133:principle).
1119:attenuation
1105:demodulator
1042:real-valued
927:symbol rate
795:symbol rate
525:(sometimes
523:demodulator
508:demodulated
412:electronics
309:Line coding
3802:Categories
3582:DirectBand
3568:Subcarrier
3270:modulation
3131:Antarctica
3090:Toasternet
3012:Television
2495:Paul Baran
2427:Television
2411:(teletype)
2404:Telegraphy
2382:transistor
2360:Phryctoria
2330:Photophone
2308:Smartphone
2298:Mass media
2031:October 5,
1918:2020-05-15
1868:2024-06-17
1796:newspapers
1742:References
1700:Heterodyne
1626:Morse code
1500:pulse wave
1484:line codes
666:magnitude.
626:networks,
606:(bits), a
485:radio wave
473:radio wave
446:microphone
420:modulation
99:modulation
3645:AM stereo
3504:Sirius XM
3497:providers
3416:Satellite
3115:Americas
3104:Locations
3075:Internet2
2836:Bandwidth
2540:Vint Cerf
2437:streaming
2415:Telephone
2355:Semaphore
2246:streaming
1826:June 2008
1705:Line code
1511:line code
1504:quantized
1057:modulator
1050:RF signal
931:baud rate
608:bitstream
584:frequency
576:amplitude
515:modulator
469:frequency
462:bitstream
18:Modulated
3744:Cultural
3674:Magnavox
3647:formats)
3597:SCA/SCMO
3592:RDS/RBDS
3395:HD Radio
3385:DRM/DRM+
3380:DAB/DAB+
3183:Category
3070:Internet
3060:CYCLADES
2977:Ethernet
2927:Concepts
2851:terminal
2802:wireless
2625:Bob Kahn
2468:Pioneers
2293:Internet
2184:Cable TV
1893:June 19,
1888:wimo.com
1663:See also
1233:π/4–QPSK
1092:using a
803:bit rate
699:(DSB-RC)
693:(DSB-SC)
556:passband
550:baseband
528:detector
424:waveform
291:See also
96:Passband
3570:signals
3538:AMR-WB+
3390:FMeXtra
3203:Commons
3193:Outline
3146:Oceania
3065:FidoNet
3050:ARPANET
2863:circuit
2432:digital
2161:History
2068:1137231
1810:scholar
1576:(ADPCM)
1570:(DPCM)
1408:in the
1323:(CPFSK)
1080:, DSP).
1028:is the
1024:(where
1016:signal
767:digital
754:f(AM,ǿ)
543:ulator–
519:circuit
456:, or a
444:from a
56:Please
3664:Harris
3659:C-QUAM
3548:HE-AAC
3525:Codecs
3509:Canada
3475:DVB-SH
3449:S band
3444:L band
3430:C band
3354:L band
3245:Analog
3141:Europe
3111:Africa
3095:Usenet
3055:BITNET
2992:Mobile
2868:packet
2377:MOSFET
2372:device
2169:Beacon
2066:
1992:
1812:
1805:
1798:
1791:
1783:
1564:(PCM)
1365:(DSSS)
1317:(GMSK)
1276:M-ary
1259:(DTMF)
1247:(AFSK)
1241:(FSK)
1205:(PSK)
1123:fading
1069:Adapt
883:symbol
876:binary
839:keying
672:analog
568:analog
539:(from
217:SC-FDE
3654:Belar
3480:S-DMB
3470:DAB-S
3375:CAM-D
3288:COFDM
3267:Radio
3124:South
3119:North
3080:JANET
3017:Telex
3007:Radio
2846:Nodes
2841:Links
2762:media
2340:Radio
2325:Pager
2253:Drums
2219:video
2214:image
2204:audio
2025:(PDF)
2014:(PDF)
1937:(PDF)
1817:JSTOR
1803:books
1710:Modem
1680:Codec
1610:(PDM)
1602:(ADM)
1551:(PPM)
1545:(PFM)
1533:(PAM)
1311:(MSK)
1267:(ASK)
1228:OQPSK
933:) is
727:(QAM)
566:, an
537:modem
487:to a
442:sound
314:Modem
3602:DARC
3577:AMSS
3558:DRA+
3439:band
3348:high
3247:and
3136:Asia
3022:UUCP
2982:ISDN
2075:2021
2064:PMID
2033:2021
1990:ISBN
1971:link
1967:link
1895:2024
1789:news
1654:The
1592:(ΣΔ)
1455:and
1441:CDMA
1398:OFDM
1388:GMSK
1386:and
1282:8VSB
962:baud
879:bits
799:baud
624:WiFi
491:.
448:, a
414:and
354:OFDM
283:THSS
278:FHSS
273:DSSS
187:MFSK
172:APSK
3587:PAD
3543:HDC
3533:AAC
3485:SDR
3465:ADR
3399:CDR
3358:UHF
3344:mid
3340:low
3336:VHF
3027:WAN
2997:NGN
2987:LAN
2268:Fax
2209:DCT
2056:doi
1949:doi
1772:by
1628:at
1488:DSL
1384:MSK
1052:).
1048:or
1036:or
777:).
765:In
670:In
562:In
545:dem
541:mod
410:In
359:FDM
349:ΔΣM
344:PWM
339:PDM
334:PCM
329:PAM
324:PoM
319:AnM
268:CSS
250:WDM
245:QAM
227:WDM
222:TCM
212:QAM
207:PSK
202:PPM
197:OOK
192:MSK
182:FSK
177:CPM
167:ASK
149:SSB
139:QAM
60:to
3804::
3346:/
3342:/
3330:HF
3326:SW
3320:MF
3316:MW
3310:LF
3306:LW
3283:FM
3278:AM
2062:.
2050:.
2016:.
1963:}}
1959:{{
1943:.
1939:.
1911:.
1886:.
1860:.
1490:.
1427:,
1190:.
1140:).
1125:).
1022:jQ
841::
829:.
559:.
513:A
418:,
144:SM
134:PM
129:FM
124:AM
3437:u
3435:K
3360:)
3356:(
3350:)
3338:(
3332:)
3328:(
3322:)
3318:(
3312:)
3308:(
3237:e
3230:t
3223:v
3154:)
3150:(
2145:e
2138:t
2131:v
2077:.
2058::
2035:.
1998:.
1973:)
1955:.
1951::
1945:1
1921:.
1897:.
1871:.
1839:)
1833:(
1828:)
1824:(
1814:·
1807:·
1800:·
1793:·
1766:.
1651:.
1431:(
1230:)
1026:j
1020:+
1018:I
980:S
976:f
972:N
946:S
942:f
923:N
907:N
903:2
899:=
896:M
391:e
384:t
377:v
83:)
77:(
72:)
68:(
54:.
34:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
