66:
isolate both systems (temporally, spectrally or spatially). This results in stove pipe designs that lack back compatibility. Future of hybrid RF systems demand co-existence and cooperation between sensibilities with flexible system design and implementation. Hence, achieving RF convergence can be an incredibly complex and difficult problem to solve. Even for a simple network consisting of one remote sensing and communications system each, there are several independent factors in the time, space, and frequency domains that have to be taken into consideration in order to determine the optimal method to share spectral resources. For a given spectrum-space-time resource manifold, a practical network will incorporate numerous remote sensing modalities and communications systems, making the problem of achieving RF convergence intangible.
96:(DARPA) and others have begun funding research that investigates methods of coexistence for military radar systems, such that their performance will not be affected when sharing spectrum with communications systems. These agencies are also interested in fundamental research investigating the limits of cooperation between military radar and communications systems that in the long run will lead to better co-design methods that improve performance. However, the problems caused by spectrum sharing do not affect just military systems. There are a wide variety of remote sensing and communications applications that will be adversely affected by sharing spectrum with communications systems such as automotive radars,
196:. These different levels range from complete isolation, to complete co-design of systems. Some levels of integration, such as non-integration (or isolation) and coexistence, are not complex in nature and do not require an overhaul of how either sensing or communications systems operate. However, this lack of complexity also implies that joint systems employing such methods of system integration will not see significant performance benefits on achieving RF convergence. As such, non-integration and coexistence methods are more short-term solutions to the spectral congestion problem. In the long term, systems will have to be co-designed together to see significant improvements in joint system performance.
121:) is beforehand, every system operates under the assumption that it is either previously estimated or its underlying probability distribution is known. Due to both systems’ conflicting nature, it is clear that when it comes to designing systems that can jointly sense and communicate, the solution is non-trivial. Due to difficulties in jointly sensing and communicating, both systems are often designed to be isolated in time, space, and/or frequency. Often, the only time legacy systems consider the other user in their mode of operation is through regulations, which are defined by agencies such as the
232:
isolated approach to system design. Co-designed systems are not necessarily physically co-located. When operating from the same platform, co-design includes the cases where radar beams and waveforms are modulated to convey communications messages, an approach which is typically referred to as dual function radar communications systems. For example, some recent experimentally demonstrated co-design approaches include:
205:
systems that employ non-integration methods end up interfering with each other, and due to the philosophy of isolation being employed, each system makes no attempt at interference mitigation. Consequentially, each user's performance is degraded. Non-integration is one of the common and traditional solutions, and as highlighted here, is a part of the problem.
223:
perform interference mitigation and subsequently improve their performance. Systems willingly share necessary information with each other in order to facilitate mutual interference mitigation. Cooperative methods are the first step toward designing joint systems and achieving RF convergence as an effective solution to the spectral congestion problem..
117:
case of a radar system, the known information is the transmitted signal and the unknown information is the target channel that is desired to be estimated. On the other hand, a communications system basically sends unknown information into a known environment. Although a communications system does not know what the environment (also called a
75:
231:
Co-design methods consist of jointly considering radar and communications systems when designing new systems to optimally share spectral resources. Such systems are jointly designed from scratch to efficiently utilize the spectrum and can potentially result in performance benefits when compared to an
204:
Systems employing non-integration methods are forced to operate in isolated regions of spectrum-space-time. However, in the real world, perfect isolation is not realizable and as a result, isolated systems will leak out and occupy segments of spectrum-space-time occupied by other systems. This is why
78:
Notional example of a simple network topology that highlights the current RF spectrum challenges. The network consists of two users, a communications user and a radar user, and a source of external interference. Users can operate either by occupying the same spectrum or by being physically co-located
133:
Several applications can benefit from RF convergence research such as autonomous driving, cloud-based medical devices, light based applications etc. Each application may have different goals, requirements, and regulations which present different challenges to achieving RF convergence. A few examples
91:
sharing between radar and communications applications was proposed as a way to alleviate the issues caused by spectral congestion. This has led to a greater emphasis being placed by researchers into investigating methods of radar-communications cooperation and co-design. Government agencies such as
20:
An example of what a typical communications and remote sensing network would like. As more systems get added to a network, determining the optimal method of operation between all the systems (achieving RF convergence) becomes increasingly difficult. Instead of considering each other as a source of
213:
Remote sensing and communications systems that implement coexistence methods are forced to coexist with each other and treat each other as sources of interference. This means that unlike non-integration methods, each system tries to perform interference mitigation. However, since both systems are
116:
Remote sensing and communications fundamentally tend to conflict with one another. Remote sensing typically transmits known information into the environment (or channel) and measures a reflected response, which is then used to extract unknown information about the environment. For example, in the
65:
are jointly shared by all nodes (or systems) of the network in a mutually beneficial manner. Remote sensing and communications have conflicting requirements and functionality. Furthermore, spectrum sharing approaches between remote sensing and communications have traditionally been to separate or
44:
systems have to share a finite amount of resources among each other. RF convergence indicates the ideal operating point for the entire network of RF systems sharing resources such that the systems can efficiently share resources in a manner that's mutually beneficial. With communications spectral
222:
Cooperative techniques, unlike coexistence methods, do not require that both sensing and communications systems treat each other as sources of interference and both systems share some knowledge or information. Cooperative methods exploit this joint knowledge to enable both systems to effectively
125:(United States), that constrain the other user's functionality. As spectral congestion continues to force both remote sensing and communications system to share spectral resources, achieving RF convergence is the solution to optimally function in an increasingly crowded wireless spectrum.
214:
not cooperative and have no knowledge about the other system, any information required to perform such interference mitigation is not shared or known and has to be estimated. As a result, interference mitigation performance is limited since it is dependent on the estimated information.
1015:
McCormick, Patrick M.; Ravenscroft, Brandon; Blunt, Shannon D.; Duly, Andrew J.; Metcalf, Justin G. (2017). "Simultaneous radar and communication emissions from a common aperture, Part II: Experimentation".
112:
can stand to benefit substantially by cooperative remote sensing and communications. Consequently, researchers have started investigating fundamental approaches to joint remote sensing and communications.
17:
929:
Sahin, Cenk; Metcalf, Justin G.; Kordik, Andrew; Kendo, Thomas; Corigliano, Thomas (2018). "Experimental
Validation of Phase-Attached Radar/Communication (PARC) Waveforms: Radar Performance".
888:
Ravenscroft, Brandon; McCormick, Patrick M.; Blunt, Shannon D.; Perrins, Erik; Metcalf, Justin G. (2018). "A power-efficient formulation of tandem-hopped radar & communications".
79:(occupying the same space). Regardless of the mode of operation, both systems will interfere with each other and interference mitigation is needed to maintain optimal performance.
392:
21:
interference, the next generation of systems must be co-designed from scratch such that each system's functionality takes into account the presence of other systems.
845:
Hassanien, Aboulnasr; Amin, Moeness G.; Zhang, Yimin D.; Ahmad, Fauzia (October 2016). "Signaling strategies for dual-function radar communications: an overview".
713:
Gu, Changzhan; Peng, Zhengyu; Li, Changzhi (2016). "High-Precision Motion
Detection Using Low-Complexity Doppler Radar with Digital Post-Distortion Technique".
970:
McCormick, Patrick M.; Blunt, Shannon D.; Metcalf, Justin G. (2017). "Simultaneous radar and communications emissions from a common aperture, Part I: Theory".
549:
Sturm, Christian; Wiesbeck, Werner (2011). "Waveform Design and Signal
Processing Aspects for Fusion of Wireless Communications and Radar Sensing".
484:
672:
Alamri, Atif; Ansari, Wasai Shadab; Hassan, Mohammad Mehedi; Hossain, M. Shamim; Alelaiwi, Abdulhameed; Hossain, M. Anwar (January 2013).
61:. Consequentially, RF convergence is commonly referred to as the operating point of a remote sensing and communications network at which
763:
Langer, Klaus-Dieter; Grubor, Jelena (2007). "Recent
Developments in Optical Wireless Communications using Infrared and Visible Light".
416:
Chiriyath, Alex R.; Paul, Bryan; Bliss, Daniel W. (2017). "Radar-Communications
Convergence: Coexistence, Cooperation, and Co-Design".
237:
1037:
991:
946:
905:
1067:
1072:
821:
780:
648:
522:
460:
138:
122:
87:. This congestion may degrade communications performance and decrease or even restrict access to spectral resources.
49:
sector, researchers have begun studying methods of achieving RF convergence for cooperative spectrum sharing between
603:
311:
Griffiths, Hugh; Cohen, Lawrence; Watts, Simon; Mokole, Eric; Baker, Chris; Wicks, Mike; Blunt, Shannon (2015).
174:
143:
62:
248:
393:"RF Communications and Sensing Convergence: Theory, Systems, and MATLAB-in-the-Loop Experiments Video"
1077:
288:
500:"Visible light communications: Application to cooperation between vehicles and road infrastructures"
499:
84:
806:
Conference Record of the Thirty-Sixth
Asilomar Conference on Signals, Systems and Computers, 2002
278:
181:
258:(MIMO) waveforms produce separate radar and communication beams in different spatial directions
273:
151:
118:
83:
Spectral congestion is caused by too many RF communications users concurrently accessing the
58:
364:
241:
88:
498:
Cailean, A.; Cagneau, B.; Chassagne, L.; Topsu, S.; Alayli, Y.; Blosseville, J-M. (2012).
8:
283:
155:
97:
368:
1043:
997:
952:
911:
870:
827:
786:
726:
654:
633:
4th IEEE International
Conference on Cloud Computing Technology and Science Proceedings
566:
528:
478:
433:
193:
745:
192:
Joint sensing-communications systems can be designed based on four different types of
1033:
987:
942:
901:
862:
817:
776:
695:
644:
518:
466:
456:
46:
37:
1047:
1001:
956:
915:
831:
790:
730:
658:
437:
1025:
979:
934:
893:
874:
854:
809:
768:
718:
685:
636:
570:
558:
532:
510:
425:
372:
324:
640:
109:
41:
377:
352:
1029:
983:
938:
897:
813:
772:
562:
329:
312:
105:
50:
722:
470:
429:
1061:
866:
858:
699:
514:
187:
313:"Radar Spectrum Engineering and Management: Technical and Regulatory Issues"
16:
160:
690:
673:
804:
Bidigare, P. (2002). "The
Shannon channel capacity of a radar system".
627:
Fortino, Giancarlo; Pathan, Mukaddim; Di Fatta, Giuseppe (2012). "Body
128:
674:"A Survey on Sensor-Cloud: Architecture, Applications, and Approaches"
45:
congestion recently becoming an increasingly important issue for the
236:
Tandem hopped radar and communications (THoRaCs), where undistorted
74:
765:
2007 9th
International Conference on Transparent Optical Networks
139:
Intelligent
Transport Systems (Vehicle-to-vehicle Communications)
887:
134:
of joint sensing-communications applications are listed below.
604:"Shared Spectrum Access for Radar and Communications (SSPARC)"
353:"Survey of RF Communications and Sensing Convergence Research"
1014:
268:
169:
165:
93:
54:
631:: Integration of Cloud Computing and body sensor networks".
497:
418:
IEEE Transactions on Cognitive Communications and Networking
255:
455:. Blunt, Shannon D.; Perrins, Erik Samuel, 1973-. Edison.
351:
Paul, Bryan; Chiriyath, Alex R.; Bliss, Daniel W. (2017).
188:
Joint sensing-communications system design and integration
671:
310:
247:
Phase-attached radar/communication (PARC), where FM and
928:
844:
101:
969:
626:
584:
Orlando, V (1989). "The Mode S beacon radar system".
254:
Far-field radiated emission design (FFRED), where FM
715:
IEEE Transactions on Microwave Theory and Techniques
678:
International Journal of Distributed Sensor Networks
451:
Blunt, Shannon D.; Perrins, Erik S. (October 2018).
129:
Applications of joint sensing-communications systems
415:
350:
544:
542:
1059:
931:2018 International Conference on Radar (RADAR)
847:IEEE Aerospace and Electronic Systems Magazine
539:
548:
94:The Defense Advanced Research Projects Agency
762:
450:
483:: CS1 maint: location missing publisher (
238:orthogonal frequency-division multiplexing
689:
376:
328:
161:High Frequency Imaging and Communications
890:2018 IEEE Radar Conference (RadarConf18)
803:
712:
507:2012 IEEE Intelligent Vehicles Symposium
453:Radar and communication spectrum sharing
240:(OFDM) sub-carriers are embedded into a
73:
15:
583:
251:(CPM) are merged into a single waveform
40:paradigm that is utilized when several
1060:
346:
344:
342:
340:
306:
304:
104:etc. Furthermore, applications like
148:Communications & Military Radar
13:
1018:2017 IEEE Radar Conference (Radar
972:2017 IEEE Radar Conference (Radar
743:
256:multiple-input and multiple-output
199:
14:
1089:
808:. Vol. 1. pp. 113–117.
337:
301:
1008:
963:
922:
881:
838:
797:
756:
737:
706:
665:
620:
26:Electromagnetic radio frequency
596:
577:
491:
444:
409:
385:
217:
208:
1:
641:10.1109/cloudcom.2012.6427537
294:
69:
226:
7:
1068:Radio frequency propagation
746:"Google Gestures at 60 GHz"
378:10.1109/access.2016.2639038
262:
249:continuous phase modulation
10:
1094:
1073:Electromagnetic components
1030:10.1109/RADAR.2017.7944480
984:10.1109/RADAR.2017.7944478
939:10.1109/RADAR.2018.8557302
898:10.1109/RADAR.2018.8378708
814:10.1109/acssc.2002.1197159
773:10.1109/icton.2007.4296267
586:Lincoln Laboratory Journal
563:10.1109/jproc.2011.2131110
330:10.1109/jproc.2014.2365517
723:10.1109/tmtt.2016.2519881
430:10.1109/TCCN.2017.2666266
289:Radio resource management
152:Remote Medical Monitoring
144:Commercial Flight Control
859:10.1109/MAES.2016.150225
515:10.1109/ivs.2012.6232225
182:Wireless Sensor Networks
156:Wearable Medical Sensors
85:electromagnetic spectrum
551:Proceedings of the IEEE
317:Proceedings of the IEEE
279:Co-channel interference
1024:. pp. 1697–1702.
978:. pp. 1685–1690.
892:. pp. 1061–1066.
509:. pp. 1055–1059.
274:Communications Systems
106:autonomous automobiles
80:
59:communications systems
22:
77:
19:
767:. pp. 146–151.
635:. pp. 851–856.
242:frequency modulation
177:& Asset Tracking
691:10.1155/2013/917923
369:2017IEEEA...5..252P
284:Spectrum Management
244:(FM) radar waveform
119:propagation channel
110:smart home networks
194:system integration
81:
63:spectral resources
47:telecommunications
23:
1039:978-1-4673-8823-8
993:978-1-4673-8823-8
948:978-1-5386-7217-4
907:978-1-5386-4167-5
744:Lipsky, Jessica.
397:www.mathworks.com
53:systems (such as
38:signal-processing
1085:
1078:Electromagnetism
1052:
1051:
1012:
1006:
1005:
967:
961:
960:
933:. pp. 1–6.
926:
920:
919:
885:
879:
878:
842:
836:
835:
801:
795:
794:
760:
754:
753:
741:
735:
734:
710:
704:
703:
693:
669:
663:
662:
624:
618:
617:
615:
614:
600:
594:
593:
581:
575:
574:
557:(7): 1236–1259.
546:
537:
536:
504:
495:
489:
488:
482:
474:
448:
442:
441:
413:
407:
406:
404:
403:
389:
383:
382:
380:
348:
335:
334:
332:
308:
1093:
1092:
1088:
1087:
1086:
1084:
1083:
1082:
1058:
1057:
1056:
1055:
1040:
1013:
1009:
994:
968:
964:
949:
927:
923:
908:
886:
882:
843:
839:
824:
802:
798:
783:
761:
757:
742:
738:
711:
707:
670:
666:
651:
625:
621:
612:
610:
602:
601:
597:
582:
578:
547:
540:
525:
502:
496:
492:
476:
475:
463:
449:
445:
414:
410:
401:
399:
391:
390:
386:
349:
338:
309:
302:
297:
265:
229:
220:
211:
202:
200:Non-integration
190:
131:
98:medical devices
72:
12:
11:
5:
1091:
1081:
1080:
1075:
1070:
1054:
1053:
1038:
1007:
992:
962:
947:
921:
906:
880:
837:
823:978-0780375765
822:
796:
782:978-1424412488
781:
755:
736:
705:
664:
649:
619:
595:
576:
538:
523:
490:
461:
443:
408:
384:
336:
299:
298:
296:
293:
292:
291:
286:
281:
276:
271:
264:
261:
260:
259:
252:
245:
228:
225:
219:
216:
210:
207:
201:
198:
189:
186:
185:
184:
178:
172:
163:
158:
149:
146:
141:
130:
127:
71:
68:
51:remote sensing
9:
6:
4:
3:
2:
1090:
1079:
1076:
1074:
1071:
1069:
1066:
1065:
1063:
1049:
1045:
1041:
1035:
1031:
1027:
1023:
1019:
1011:
1003:
999:
995:
989:
985:
981:
977:
973:
966:
958:
954:
950:
944:
940:
936:
932:
925:
917:
913:
909:
903:
899:
895:
891:
884:
876:
872:
868:
864:
860:
856:
853:(10): 36–45.
852:
848:
841:
833:
829:
825:
819:
815:
811:
807:
800:
792:
788:
784:
778:
774:
770:
766:
759:
751:
747:
740:
732:
728:
724:
720:
716:
709:
701:
697:
692:
687:
684:(2): 917923.
683:
679:
675:
668:
660:
656:
652:
650:9781467345101
646:
642:
638:
634:
630:
623:
609:
608:www.darpa.mil
605:
599:
592:(3): 345–362.
591:
587:
580:
572:
568:
564:
560:
556:
552:
545:
543:
534:
530:
526:
524:9781467321181
520:
516:
512:
508:
501:
494:
486:
480:
472:
468:
464:
462:9781785613579
458:
454:
447:
439:
435:
431:
427:
423:
419:
412:
398:
394:
388:
379:
374:
370:
366:
362:
358:
354:
347:
345:
343:
341:
331:
326:
322:
318:
314:
307:
305:
300:
290:
287:
285:
282:
280:
277:
275:
272:
270:
267:
266:
257:
253:
250:
246:
243:
239:
235:
234:
233:
224:
215:
206:
197:
195:
183:
179:
176:
173:
171:
167:
164:
162:
159:
157:
153:
150:
147:
145:
142:
140:
137:
136:
135:
126:
124:
120:
114:
111:
107:
103:
99:
95:
90:
86:
76:
67:
64:
60:
56:
52:
48:
43:
39:
35:
31:
27:
18:
1021:
1017:
1010:
975:
971:
965:
930:
924:
889:
883:
850:
846:
840:
805:
799:
764:
758:
749:
739:
714:
708:
681:
677:
667:
632:
628:
622:
611:. Retrieved
607:
598:
589:
585:
579:
554:
550:
506:
493:
452:
446:
421:
417:
411:
400:. Retrieved
396:
387:
360:
356:
320:
316:
230:
221:
212:
203:
191:
132:
115:
82:
33:
29:
25:
24:
363:: 252–270.
357:IEEE Access
218:Cooperation
209:Coexistence
34:convergence
1062:Categories
613:2018-07-27
471:1079815876
402:2019-03-21
323:: 85–102.
295:References
70:Motivation
867:0885-8985
700:1550-1477
479:cite book
227:Co-design
1048:21968573
1002:22734837
957:54451278
916:49190086
832:22136743
791:17692631
750:EE Times
731:17399822
717:: 1–11.
659:17482174
438:13648867
424:: 1–12.
263:See also
180:Capable
89:Spectrum
875:8128653
571:1002111
533:6069018
365:Bibcode
1046:
1036:
1000:
990:
955:
945:
914:
904:
873:
865:
830:
820:
789:
779:
729:
698:
657:
647:
569:
531:
521:
469:
459:
436:
57:) and
1044:S2CID
998:S2CID
953:S2CID
912:S2CID
871:S2CID
828:S2CID
787:S2CID
727:S2CID
655:S2CID
629:Cloud
567:S2CID
529:S2CID
503:(PDF)
434:S2CID
269:Radar
170:Lidar
166:Li-Fi
55:radar
36:is a
1034:ISBN
1020:Conf
988:ISBN
974:Conf
943:ISBN
902:ISBN
863:ISSN
818:ISBN
777:ISBN
696:ISSN
645:ISBN
519:ISBN
485:link
467:OCLC
457:ISBN
175:RFID
168:and
154:and
108:and
1026:doi
980:doi
935:doi
894:doi
855:doi
810:doi
769:doi
719:doi
686:doi
637:doi
559:doi
511:doi
426:doi
373:doi
325:doi
321:103
123:FCC
1064::
1042:.
1032:.
996:.
986:.
951:.
941:.
910:.
900:.
869:.
861:.
851:31
849:.
826:.
816:.
785:.
775:.
748:.
725:.
694:.
680:.
676:.
653:.
643:.
606:.
588:.
565:.
555:99
553:.
541:^
527:.
517:.
505:.
481:}}
477:{{
465:.
432:.
420:.
395:.
371:.
359:.
355:.
339:^
319:.
315:.
303:^
102:5G
100:,
42:RF
32:)
30:RF
1050:.
1028::
1022:)
1004:.
982::
976:)
959:.
937::
918:.
896::
877:.
857::
834:.
812::
793:.
771::
752:.
733:.
721::
702:.
688::
682:9
661:.
639::
616:.
590:2
573:.
561::
535:.
513::
487:)
473:.
440:.
428::
422:3
405:.
381:.
375::
367::
361:5
333:.
327::
28:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
