25:
145:
153:
The level of noise determines the maximum sensitivity and reception range of a radio receiver; if no noise were picked up with radio signals, even weak transmissions could be received at virtually any distance by making a radio receiver that was sensitive enough. With noise present, if a radio source
158:(S/N), the ratio of the average amplitude of the signal voltage to the average amplitude of the noise voltage. When this ratio is below one (0 dB) the noise is greater than the signal, requiring special processing to recover the information.
148:
Atmospheric noise as a function of frequency in the LF, MF, and HF radio spectrum according to CCIR 322. The vertical axis is in decibels above the thermal noise floor. It can be seen that as frequency drops atmospheric noise dominates other
154:
is so weak and far away that the radio signal in the receiver has a lower amplitude than the average noise, the noise will drown out the signal. The level of noise in a communications circuit is measured by the
224:
is experienced at frequencies above about 15 MHz when highly directional antennas are pointed toward the sun or to certain other regions of the sky such as the center of the Milky Way Galaxy.
301:
290:
54:
227:
Electromagnetic noise can interfere with electronic equipment in general, causing malfunction, and in recent years standards have been laid down for the levels of
812:
461:
204:
and above, these sources are often lower, and thermal noise is usually the limiting factor. In the most sensitive receivers at these frequencies,
628:
265:
965:
161:
The limiting noise source in a receiver depends on the frequency range in use. At frequencies below about 40 MHz, particularly in the
822:
704:
618:
76:
959:
807:
658:
336:
492:
232:
1001:
868:
775:
130:
118:
37:
623:
345:
47:
41:
33:
548:
918:
441:
228:
231:
that electronic equipment is permitted to radiate. These standards are aimed at ensuring what is referred to as
58:
832:
421:
209:
755:
690:
653:
944:
789:
633:
155:
853:
370:
201:
613:
608:
426:
329:
197:
669:
559:
883:
878:
674:
498:
395:
380:
360:
170:
122:
273:
Measurements and models of radio frequency impulsive noise for indoor wireless communications
976:
949:
503:
436:
400:
121:
with it in the receiver's circuits. Radio noise is a combination of natural electromagnetic
954:
908:
873:
863:
431:
390:
205:
182:
141:
present in the receiver input circuits, caused by the random thermal motion of molecules.
134:
102:
314:
583:
528:
508:
322:
178:
106:
995:
939:
913:
648:
523:
476:
471:
466:
456:
451:
375:
190:
138:
638:
588:
518:
221:
213:
970:
664:
643:
578:
570:
513:
446:
385:
309:
Characteristics of impulsive noise in the 450-MHz band in hospitals and clinics
144:
565:
554:
538:
533:
365:
244:
162:
279:
858:
298:
Impulsive noise measurements and characterization in a UHF digitalTV channel
217:
126:
125:("spherics", static) created by electrical processes in the atmosphere like
110:
275:. IEEE Journal on Selected Areas in Communications 11 (7), September 1993.
186:
166:
114:
261:
923:
297:
286:
272:
311:. IEEE Transactions on Antennas and Propagation 46 (2), February 1998.
308:
543:
174:
765:
741:
726:
719:
416:
249:
143:
90:
133:(RFI) from other electrical devices picked up by the receiver's
318:
280:
Measurement and analysis of man-made noise in VHF and UHF bands
105:
electrical signals, fluctuating voltages, always present in a
18:
196:
These noises are often referred to as static. Conversely, at
109:
in addition to the desired radio signal. Radio noise near in
113:
to the radio signal being received (in the receiver's
287:
Statistics of motor vehicle ignition noise at VHF/UHF
932:
901:
892:
846:
683:
599:
485:
409:
353:
212:antennas, thermal noise is reduced by cooling the
189:, and other man-made sources tend to be above the
46:but its sources remain unclear because it lacks
330:
173:and nearby radio frequency interference from
8:
282:. Wireless Communications Conference, 1997.
898:
337:
323:
315:
77:Learn how and when to remove this message
813:Signal-to-interference-plus-noise ratio
629:Equivalent pulse code modulation noise
266:International Telecommunication Union
7:
752:(energy per symbol to noise density)
307:Blankenship, T.K.; Rappaport, T.S.:
823:Signal-to-quantization-noise ratio
193:floor in the receiver's circuits.
14:
737:(energy per bit to noise density)
705:Carrier-to-receiver noise density
619:Effective input noise temperature
348:(physics and telecommunications)
302:IEEE Trans. Electromagn. Compat.
291:IEEE Trans. Electromagn. Compat.
23:
16:Unwanted radio frequency signals
960:Block-matching and 3D filtering
808:Signal-to-noise ratio (imaging)
659:Noise, vibration, and harshness
285:Lauber, W.R.; Bertrand, J.M.:
264:. ITU-R Recommendation P.372,
1:
493:Additive white Gaussian noise
233:electromagnetic compatibility
869:Interference (communication)
776:Signal-to-interference ratio
766:Signal, noise and distortion
131:radio frequency interference
624:Equivalent noise resistance
1018:
919:Total variation denoising
229:electromagnetic radiation
97:(commonly referred to as
271:Blackard, K.L.; et al.:
32:This article includes a
833:Contrast-to-noise ratio
296:Sanchez, M.G.; et al.:
222:Cosmic background noise
210:satellite communication
61:more precise citations.
756:Modulation error ratio
691:Carrier-to-noise ratio
654:Noise spectral density
150:
971:Denoising autoencoder
945:Anisotropic diffusion
790:Signal-to-noise ratio
634:Impulse noise (audio)
549:Johnson–Nyquist noise
437:Government regulation
156:signal-to-noise ratio
147:
101:) is unwanted random
854:List of noise topics
293:41 (3), August 1999.
202:ultra high frequency
1002:Noise (electronics)
614:Circuit noise level
609:Channel noise level
278:Dalke, R.; et al.:
216:of the receiver to
198:very high frequency
175:electrical switches
670:Pseudorandom noise
560:Quantization error
371:Noise cancellation
151:
34:list of references
989:
988:
985:
984:
924:Wavelet denoising
884:Thermal radiation
879:Spectrum analyzer
675:Statistical noise
499:Atmospheric noise
396:Noise temperature
381:Noise measurement
361:Acoustic quieting
304:41 (2), May 1999.
183:ignition circuits
171:atmospheric noise
169:bands and below,
123:atmospheric noise
87:
86:
79:
1009:
977:Deep Image Prior
966:Shrinkage Fields
950:Bilateral filter
899:
504:Background noise
401:Phase distortion
339:
332:
325:
316:
206:radio telescopes
82:
75:
71:
68:
62:
57:this article by
48:inline citations
27:
26:
19:
1017:
1016:
1012:
1011:
1010:
1008:
1007:
1006:
992:
991:
990:
981:
955:Non-local means
928:
909:Low-pass filter
894:
888:
874:Noise generator
864:Colors of noise
842:
749:
745:
734:
730:
679:
601:
595:
575:Coherent noise
551:(thermal noise)
481:
405:
391:Noise reduction
349:
343:
258:
241:
103:radio frequency
83:
72:
66:
63:
52:
38:related reading
28:
24:
17:
12:
11:
5:
1015:
1013:
1005:
1004:
994:
993:
987:
986:
983:
982:
980:
979:
974:
968:
963:
957:
952:
947:
942:
936:
934:
930:
929:
927:
926:
921:
916:
911:
905:
903:
896:
890:
889:
887:
886:
881:
876:
871:
866:
861:
856:
850:
848:
847:Related topics
844:
843:
841:
840:
830:
820:
810:
805:
787:
773:
763:
753:
747:
743:
738:
732:
728:
723:
716:
702:
687:
685:
681:
680:
678:
677:
672:
667:
662:
656:
651:
646:
641:
636:
631:
626:
621:
616:
611:
605:
603:
597:
596:
594:
593:
592:
591:
586:
584:Gradient noise
581:
573:
568:
563:
557:
552:
546:
541:
536:
531:
529:Gaussian noise
526:
521:
516:
511:
509:Brownian noise
506:
501:
496:
489:
487:
486:Class of noise
483:
482:
480:
479:
474:
472:Transportation
469:
464:
459:
454:
449:
444:
439:
434:
429:
424:
419:
413:
411:
407:
406:
404:
403:
398:
393:
388:
383:
378:
373:
368:
363:
357:
355:
351:
350:
344:
342:
341:
334:
327:
319:
313:
312:
305:
294:
283:
276:
269:
257:
254:
253:
252:
247:
240:
237:
220:temperatures.
107:radio receiver
85:
84:
67:September 2011
42:external links
31:
29:
22:
15:
13:
10:
9:
6:
4:
3:
2:
1014:
1003:
1000:
999:
997:
978:
975:
972:
969:
967:
964:
961:
958:
956:
953:
951:
948:
946:
943:
941:
940:Gaussian blur
938:
937:
935:
931:
925:
922:
920:
917:
915:
914:Median filter
912:
910:
907:
906:
904:
900:
897:
891:
885:
882:
880:
877:
875:
872:
870:
867:
865:
862:
860:
857:
855:
852:
851:
849:
845:
838:
834:
831:
828:
824:
821:
818:
814:
811:
809:
806:
803:
799:
795:
791:
788:
785:
781:
777:
774:
771:
767:
764:
761:
757:
754:
751:
750:
739:
736:
735:
724:
722:
721:
717:
714:
710:
706:
703:
700:
696:
692:
689:
688:
686:
682:
676:
673:
671:
668:
666:
663:
660:
657:
655:
652:
650:
649:Noise shaping
647:
645:
642:
640:
637:
635:
632:
630:
627:
625:
622:
620:
617:
615:
612:
610:
607:
606:
604:
598:
590:
587:
585:
582:
580:
577:
576:
574:
572:
569:
567:
564:
562:(or q. noise)
561:
558:
556:
553:
550:
547:
545:
542:
540:
537:
535:
532:
530:
527:
525:
524:Flicker noise
522:
520:
517:
515:
512:
510:
507:
505:
502:
500:
497:
494:
491:
490:
488:
484:
478:
475:
473:
470:
468:
467:Sound masking
465:
463:
460:
458:
455:
453:
450:
448:
445:
443:
440:
438:
435:
433:
430:
428:
425:
423:
420:
418:
415:
414:
412:
408:
402:
399:
397:
394:
392:
389:
387:
384:
382:
379:
377:
376:Noise control
374:
372:
369:
367:
364:
362:
359:
358:
356:
352:
347:
340:
335:
333:
328:
326:
321:
320:
317:
310:
306:
303:
299:
295:
292:
288:
284:
281:
277:
274:
270:
267:
263:
260:
259:
255:
251:
248:
246:
243:
242:
238:
236:
234:
230:
225:
223:
219:
215:
211:
207:
203:
199:
194:
192:
191:thermal noise
188:
184:
180:
176:
172:
168:
164:
159:
157:
146:
142:
140:
139:thermal noise
136:
132:
128:
124:
120:
116:
112:
108:
104:
100:
96:
92:
81:
78:
70:
60:
56:
50:
49:
43:
39:
35:
30:
21:
20:
836:
826:
816:
801:
797:
793:
783:
779:
769:
759:
740:
725:
718:
712:
708:
698:
694:
639:Noise figure
600:Engineering
589:Worley noise
519:Cosmic noise
442:Human health
226:
214:RF front end
195:
160:
152:
99:radio static
98:
94:
88:
73:
64:
53:Please help
45:
665:Phase noise
644:Noise floor
579:Value noise
571:White noise
514:Burst noise
432:Environment
427:Electronics
410:Noise in...
386:Noise power
262:Radio noise
129:, manmade
95:radio noise
93:reception,
59:introducing
933:2D (Image)
566:Shot noise
555:Pink noise
539:Infrasound
534:Grey noise
366:Distortion
256:References
245:Shot Noise
181:, vehicle
163:mediumwave
119:interferes
859:Acoustics
422:Buildings
268:, Geneva.
218:cryogenic
187:computers
127:lightning
111:frequency
996:Category
893:Denoise
239:See also
167:longwave
149:sources.
115:passband
902:General
895:methods
800:,
354:General
235:(EMC).
135:antenna
55:improve
962:(BM3D)
684:Ratios
544:Jitter
495:(AWGN)
447:Images
179:motors
137:, and
973:(DAE)
770:SINAD
720:dBrnC
661:(NVH)
602:terms
477:Video
462:Ships
457:Rooms
452:Radio
417:Audio
346:Noise
250:Noise
91:radio
40:, or
827:SQNR
817:SINR
208:and
200:and
165:and
837:CNR
802:SNR
760:MER
89:In
998::
746:/N
731:/N
713:kT
300:.
289:.
185:,
177:,
117:)
44:,
36:,
839:)
835:(
829:)
825:(
819:)
815:(
804:)
798:N
796:/
794:S
792:(
786:)
784:I
782:/
780:S
778:(
772:)
768:(
762:)
758:(
748:0
744:s
742:E
733:0
729:b
727:E
715:)
711:/
709:C
707:(
701:)
699:N
697:/
695:C
693:(
338:e
331:t
324:v
80:)
74:(
69:)
65:(
51:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
