41:
633:
370:
In phase modulation, the instantaneous amplitude of the baseband signal modifies the phase of the carrier signal keeping its amplitude and frequency constant. The phase of a carrier signal is modulated to follow the changing signal level (amplitude) of the message signal. The peak amplitude and the
508:
875:
821:
948:
623:
974:
725:
567:
538:
915:, this quantity indicates by how much the modulated variable varies around its unmodulated level. It relates to the variations in the phase of the carrier signal:
895:
371:
frequency of the carrier signal are maintained constant, but as the amplitude of the message signal changes, the phase of the carrier changes correspondingly.
323:
287:
734:
In principle, the modulating signal in both frequency and phase modulation may either be analog in nature, or it may be digital.
374:
Phase modulation is an integral part of many digital transmission coding schemes that underlie a wide range of technologies like
432:
829:
316:
232:
426:
In general form, an analog modulation process of a sinusoidal carrier wave may be described by the following equation:
1073:
1040:
348:
211:
777:
105:
1095:
292:
206:
178:
145:
120:
72:
581:
is constant and the second term of the equation has a functional relationship to the modulating message signal.
1035:. Telecommunication Transmission Engineering. Vol. 1 (2nd ed.). Bell Center for Technical Education.
731:) of the carrier is controlled by the modulating waveform, such that the principal frequency remains constant.
517:
represents the time-varying amplitude of the sinusoidal carrier wave and the cosine-term is the carrier at its
309:
769:
758:
977:
989:
110:
921:
590:
411:
262:
82:
135:
956:
272:
155:
695:. These variations are controlled by both the frequency and the amplitude of the modulating wave.
91:
1010:
169:
48:
577:. In amplitude modulation, the angle term is held constant, while in angle modulation the term
282:
277:
115:
100:
701:
543:
898:
523:
415:
267:
201:
751:
626:
570:
383:
364:
125:
62:
57:
8:
585:
399:
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150:
880:
183:
160:
140:
20:
1069:
1046:
1036:
1000:
692:
518:
130:
1013:
for Pockel's Effect phase modulation for applying sidebands to a monochromatic wave
1005:
912:
738:
574:
360:
257:
252:
77:
192:
625:
as its argument, provides the distinction of the two types of angle modulation,
1089:
1050:
728:
584:
The functional form of the cosine term, which contains the expression of the
387:
40:
407:
356:
297:
237:
216:
19:
This article is about the analog modulation. For the digital version, see
16:
Modulation pattern for conditioning communication signals for transmission
569:. This description directly provides the two major groups of modulation,
1030:
994:
765:
403:
344:
32:
747:
741:
behaviour reveals that there are two regions of particular interest:
242:
755:
632:
395:
29:
976:
is the peak phase deviation. Compare to the modulation index for
1031:
Klie, Robert H.; Bell
Telephone Laboratories; AT&T (1977).
691:
In FM the message signal causes a functional variation of the
897:
is the modulation index defined below. This is also known as
391:
375:
247:
379:
503:{\displaystyle m(t)=A(t)\cdot \cos(\omega t+\phi (t))\,}
359:. Phase modulation is one of the two principal forms of
698:
In phase modulation, the instantaneous phase deviation
959:
924:
883:
870:{\displaystyle f_{\text{M}}=\omega _{\text{m}}/2\pi }
832:
780:
704:
593:
546:
526:
435:
351:. It encodes a message signal as variations in the
347:pattern for conditioning communication signals for
968:
942:
889:
869:
815:
719:
617:
561:
532:
502:
386:. However it is not widely used for transmitting
1087:
754:(AM) and exhibits its unfortunate doubling of
816:{\displaystyle 2\left(h+1\right)f_{\text{M}}}
317:
410:. A related type of sound synthesis called
324:
310:
997:for a list of other modulation techniques
540:, and the instantaneous phase deviation
499:
631:
1088:
1063:
394:waves. It is also used for signal and
1057:
768:signal, PM is similar to FM, and its
906:
13:
960:
931:
642:) is modulating the carrier wave (
14:
1107:
943:{\displaystyle h=\Delta \theta ,}
618:{\displaystyle \omega t+\phi (t)}
629:(FM) and phase modulation (PM).
39:
1024:
969:{\displaystyle \Delta \theta }
714:
708:
612:
606:
556:
550:
496:
493:
487:
472:
460:
454:
445:
439:
1:
1017:
421:
648:), resulting the PM signal (
7:
990:Automatic frequency control
983:
10:
1112:
750:signals, PM is similar to
233:Capacity-approaching codes
18:
720:{\displaystyle \phi (t)}
562:{\displaystyle \phi (t)}
1011:Electro-optic modulator
737:The mathematics of the
533:{\displaystyle \omega }
170:Hierarchical modulation
1096:Radio modulation modes
1068:. Wiley. p. 107.
1064:Haykin, Simon (2001).
970:
944:
891:
871:
817:
721:
688:
619:
563:
534:
504:
1066:Communication Systems
971:
945:
892:
872:
818:
722:
636:The modulating wave (
635:
620:
564:
535:
505:
416:Casio CZ synthesizers
978:frequency modulation
957:
922:
881:
830:
778:
761:and poor efficiency.
752:amplitude modulation
702:
627:frequency modulation
591:
571:amplitude modulation
544:
524:
433:
400:digital synthesizers
384:satellite television
365:frequency modulation
764:For a single large
586:instantaneous phase
353:instantaneous phase
966:
940:
913:modulation indices
887:
867:
813:
717:
689:
615:
559:
530:
500:
390:audio signals via
92:Digital modulation
21:Phase-shift keying
1001:Modulation sphere
890:{\displaystyle h}
853:
840:
810:
772:is approximately
693:carrier frequency
519:angular frequency
334:
333:
49:Analog modulation
1103:
1080:
1079:
1061:
1055:
1054:
1028:
1006:Polar modulation
975:
973:
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949:
947:
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941:
907:Modulation index
896:
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718:
686:
685:
683:
681:
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677:
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653:
647:
641:
624:
622:
621:
616:
575:angle modulation
568:
566:
565:
560:
539:
537:
536:
531:
509:
507:
506:
501:
412:phase distortion
363:, together with
361:angle modulation
337:Phase modulation
326:
319:
312:
43:
26:
25:
1111:
1110:
1106:
1105:
1104:
1102:
1101:
1100:
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703:
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637:
592:
589:
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545:
542:
541:
525:
522:
521:
434:
431:
430:
424:
414:is used in the
406:, to implement
330:
193:Spread spectrum
24:
17:
12:
11:
5:
1109:
1099:
1098:
1082:
1081:
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985:
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965:
962:
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939:
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933:
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927:
911:As with other
908:
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402:, such as the
398:generation in
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52:
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44:
36:
35:
15:
9:
6:
4:
3:
2:
1108:
1097:
1094:
1093:
1091:
1077:
1075:0-471-17869-1
1071:
1067:
1060:
1052:
1048:
1044:
1042:0-932764-13-4
1038:
1034:
1027:
1023:
1012:
1009:
1007:
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1002:
999:
996:
993:
991:
988:
987:
981:
979:
963:
937:
934:
928:
925:
918:
917:
916:
914:
900:
899:Carson's Rule
884:
864:
861:
857:
847:
843:
834:
804:
799:
795:
792:
789:
785:
781:
774:
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749:
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742:
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705:
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694:
673:
665:
661:
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628:
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582:
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436:
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53:
50:
47:
46:
42:
38:
37:
34:
31:
28:
27:
22:
1065:
1059:
1032:
1026:
952:
910:
736:
733:
697:
690:
671:
663:
659:
650:
644:
638:
583:
578:
514:
513:
425:
408:FM synthesis
373:
369:
357:carrier wave
349:transmission
340:
336:
335:
298:Multiplexing
238:Demodulation
67:
729:phase angle
684:×sin
243:Line coding
1033:Principles
1018:References
995:Modulation
766:sinusoidal
746:For small
422:Foundation
404:Yamaha DX7
345:modulation
33:modulation
1051:894686224
964:θ
961:Δ
935:θ
932:Δ
865:π
848:ω
770:bandwidth
759:bandwidth
748:amplitude
706:ϕ
604:ϕ
595:ω
548:ϕ
528:ω
485:ϕ
476:ω
470:
464:⋅
1090:Category
984:See also
756:baseband
739:spectral
396:waveform
225:See also
30:Passband
901:for PM.
682:
668:
658:
343:) is a
1072:
1049:
1039:
953:where
826:Where
388:analog
151:SC-FDE
651:green
392:radio
376:Wi-Fi
355:of a
248:Modem
1070:ISBN
1047:OCLC
1037:ISBN
877:and
666:) =
639:blue
579:A(t)
573:and
515:A(t)
382:and
288:OFDM
217:THSS
212:FHSS
207:DSSS
121:MFSK
106:APSK
654:).
645:red
467:cos
380:GSM
293:FDM
283:ΔΣM
278:PWM
273:PDM
268:PCM
263:PAM
258:PoM
253:AnM
202:CSS
184:WDM
179:QAM
161:WDM
156:TCM
146:QAM
141:PSK
136:PPM
131:OOK
126:MSK
116:FSK
111:CPM
101:ASK
83:SSB
73:QAM
1092::
1045:.
980:.
418:.
378:,
367:.
341:PM
78:SM
68:PM
63:FM
58:AM
1078:.
1053:.
938:,
929:=
926:h
885:h
862:2
858:/
852:m
844:=
839:M
835:f
823:,
809:M
805:f
800:)
796:1
793:+
790:h
786:(
782:2
727:(
715:)
712:t
709:(
679:2
676:/
672:π
664:t
662:(
660:g
613:)
610:t
607:(
601:+
598:t
557:)
554:t
551:(
510:.
497:)
494:)
491:t
488:(
482:+
479:t
473:(
461:)
458:t
455:(
452:A
449:=
446:)
443:t
440:(
437:m
339:(
325:e
318:t
311:v
23:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
