뗚14뻭뗚7웚 쾵 춳 럂 헦 톧 놨 Vol. 14 No. 72002쓪7퓂 JOURNAL OF SYSTEM SIMULATION July 2002컄헂뇠뫅1004-731X (2002) 07-0958-03뻟폐뗍뷘믱룅싊뗄횱탲삩욵쾵춳싞컀뇸12, 췵폀짺11 컷놱릤튵듳톧뗧ퟓ릤돌쾵, 컷낲 7100722; 커뺯릤돌톧풺춨탅릤돌쾵, 컷낲 710086햪 튪: 헫뛔뒫춳BPSK뗷훆뗄횱뷓탲쇐삩욵DSSS탅뫅틗쫜욽랽믲뇈쳘퇓동볬늨웷뷘믱뗄좱쿝놾컄폃튻훖뛠뗧욽PN싫뗷훆랽램살룄뷸횱뷓탲쇐삩욵DSSS쾵춳뗍뷘믱룅싊LPI탔쓜늢춨맽SystemView죭볾붫웤폫뒫춳DSSS쾵춳뗄LPI탔쓜뷸탐쇋럂헦뫍뇈뷏럖컶뷡맻뇭쏷룃랽램쓜폐킧뗖뾹욽랽믲뇈쳘퇓동볬늨웷뗄헬닢맘볼듊DSSSLPI캱싫SystemView훐춼럖샠뫅; 컄쿗뇪쪶싫AA Low Probability of Intercept Direct Sequence Spread Spectrum SystemsLUO Wei-bing1,2, WANG Yong-sheng11( Dept of Electronic Engineering, Northwestern Polytechnical University, Xi’an 710072, China;2 Dept of Communications Engineering, Engineering College of CAPF, Xi’an 710072, ChinaAbstract: Some special detector, such as square detector and bit delay detector, can easily detect traditional Binary Phase-Shift-Keying (BPSK) modulation signal of direct sequence spread spectrum (DSSS) systems, which was a dormantdisadvantage of carry-wave hiding. A new modulation can improve the performance of low probability of intercept (LPI) forDSSS systems by a multi-level pseudo-noise (PN) code. Performance of LPI in the new way has been simulated bySystemView software and compared the result with the traditional BPSK modulation. As result, the modulation caneffectually avoid the detection by square detector and bit delay : DSSS; low probability of Intercept; PN code; SystemView1 틽퇔1+(sinct sin/2)2= (sinct sin/2)2퓚뻼쫂컞쿟뗧춨탅쾵춳훐틾뇎탔쫇튻룶뫜훘튪뗄뫢= (1cos2ct)/2 (2)솿뇪ힼ삩욵탅뫅뗄욵웗춨뎣퇍쎻퓚퓫짹뗧욽횮쿂뛸늻틗쿔좻쪽2훐듦퓚튻룶퓘늨욵싊뗄뛾놶욵럖솿놻헬닢헢헽쫇닉폃삩욵벼쫵뗄훷튪풭틲횮튻쯤좻횱뷓틲듋헢훖뒫춳뗄DSSS틑뗷탅뫅뫜죝틗죃욽랽볬늨웷믲샠탲쇐삩욵DSSS탅뫅뗄욵웗쓜솿뇈뷏럖즢쟒퇍쎻퓚퓫쯆뗄뇈쳘퇓동쿟볬늨웷헬닢떽[1]캪듋놾컄쳡돶쇋튻훖짹뮷뺳폃웕춨뗄컞쿟욵웗볠닢틇볬닢떽뗄룅싊뫜킡떫탂뗄PN싫뗷훆랽램틔쳡룟DSSS쾵춳뗄뗍뷘믱룅싊쫇퓚쳘뇰떣탄탅뫅놻헬닢뗄펦폃뎡뫏헢쫇풶풶늻릻뗄LPI탔쓜룃랽램퓚늻퓶볓뗷훆듸뿭뫍붵뗍삩욵퓶틦뗄헢쫇틲캪죴붫탅뫅욽랽뫳뷸탐볬닢퓲뿉죝틗뗘헬닢돶잰쳡쿂뿉틔룄짆DSSS탅뫅뗄틾뇎탔뒫쫤탅뫅뗄퓘늨틔DSSS쾵춳뎣맦뗄BPSK뗷훆캪샽튻룶뗤탍뗄2 뛠뗧욽삩욵싫횱탲삩욵쾵춳DSSS틑뗷탅뫅뿉틔폃쪽1뇭쪾S(t)=A cos (ct+d(t)c(t)/2) (1)놾컄쳡돶쇋튻훖닉폃뛠뗧욽삩욵싫뗄DSSS탂랽램웤훐A캪탅뫅럹뛈d(t)캪쫤죫쫽뻝c(t)캪폃폚삩욵뗄PN죧춼1쯹쪾룃랽램평튻룶뷏룟쯙싊뗄뛾뷸훆PN싫춨맽탲쇐d(t)뫍c(t)뗄뗧욽좡횵캪1뫍+1c캪퓘늨욵싊튻룶뷏뗍뷘횹욵싊뗄뗍춨싋늨웷싋늨뫳뺭샛볓웷닺짺튻룶뛔룃탅뫅좡욽랽늢싔좥뎣쫽A2뿉뗃쿂쪽탂뗄뛠뗧욽PN싫살ퟷ캪쾵춳뗄삩욵싫헢훖탂뗄삩욵싫S2(t) = (cos(ct ±/2)2)쫇틔뇈뎣맦삩욵싫룟뗃뛠뗄쯙싊닺짺늢춨맽뗍춨싋늨웷= (cosct cos/2µsinct sin/2)2쫤돶틔뇣뗃떽폫쪵볊삩욵퓶틦쯹탨뗄듸뿭= (cosct cos/2)2µcosct sinct cos/2sin/2룃삩욵싫ퟮ훕틲뗍춨싋늨웷뗄쿞듸ퟷ폃쪹횮폫웕춨뛾 뷸훆PN싫뗄듸뿭쿠뗈춨뎣싫쯙싊뿉틔쫇뗍춨싋늨웷듸쫕룥죕웚2002-01-07 탞믘죕웚2002-03-28뿭뗄벸놶떽쪮벸놶룃삩욵싫뿉틔폐탭뛠늻춬뗄퓋폃랽쪽ퟷ헟볲뷩싞컀뇸(1969-), 쓐, 뫾쓏틦퇴죋, 늩쪿, 퇐뺿랽쿲캪횸믓ퟔ뚯뮯쾵춳벰춨탅쾵춳럂헦헢샯폃살뿘훆쫽뻝탅뫅뗷훆뗄PSK쿠캻뮻벴쎿튻룶삩; 췵폀짺(1941-), 쓐, 짂컷죋, 뷌쫚, 늩떼, 퇐뺿랽쿲캪춨탅떼몽폫닢뿘쾵춳뗄탅쾢뒫쫤뒦샭욵싫뗄뗧욽퇹횵폫짏튻룶퇹횵샛볓튲뻍쫇싫욬뗄쎿튻
뗚14뻭뗚7웚 싞컀뇸, 뗈뻟폐뗍뷘믱룅싊뗄횱탲삩욵쾵춳• 959 •룟쯙PN랢짺웷LPF웤쯼폫웕춨뗄DSSSBPSK쾵춳췪좫쿠쯆싫욬3 탔쓜럖컶벰럂헦랢짤믺c(t)퇓동 캪쇋쓜뛔쪹폃헢훖탂삩욵싫뗄DSSS쾵춳뗄LPI탔쓜d(t)s(t)x(t)탅풴뗷훆웷쿠캻뮻웷뷸탐움볛컒쏇붫웤폫뒫춳뗄BPSK횱탲삩욵쾵춳ퟷ튻뛔탅뗀뇈퓚탂쾵춳훐쎻폐쏷좷뚨틥싫쯙싊Rc뫍듸뿭BBRc퓫짹헢뻍뫜쓑좷뚨솽훖쾵춳횮볤뗄뿉뇈탔떫뿉틔톡폃퓫짹듸룟쯙n(t)PN뿭살뇈뷏퓫짹듸뿭뚨틥캪ퟜ릦싊폫놻닢탅뫅쿠춬뺭싋랢짺웷LPF늨뫳뗄룟쮹냗퓫짹탅뫅뗄듸뿭벴뷓쫕믺싫욬c’(t)퇓동BP=sPmax(fc)y(t)d’(t)탅쯞웤훐P캪탅뫅ퟜ릦싊Psmax(fc)캪퓚쯹폐욵싊짏뗄릦싊ퟮ듳뷢뗷웷쿠캻뮻웷횵춨뎣릦싊ퟮ듳횵쫇퓚탄욵싊뒦틲캪톡좡뗄솽훖탅뫅춼1 뛠뗧욽삩욵싫DSSS풭샭뿲춼뗄릦싊쿠춬죧맻욵웗뗄ퟮ듳릦싊럥횵튲쿠춬쓇쎴쯼쏇룶좡퇹폫잰튻룶좡퇹쿠뇈뷏살좷뚨쿠캻뗄뮻뗄듸뿭튲붫쿠춬평폚헢솽훖탅뫅뚼쫇쿠캻뗷훆탅뫅뻟쯤좻룃삩욵싫뻟폐폫뎣맦뛾뷸훆삩욵싫쿠춬뗄듸뿭폐뫣뚨뗄냼싧틲듋솽훖쾵춳듦퓚뿉뇈탔퓚솽룶쾵춳떫좴뻟폐탭뛠뿉쓜늻춬뗄럹횵뗧욽룃럹횵뗄럖늼쫇뻹훐뚼볙짨탅뗀쫇AWGN탅뗀헢쫇튻룶ퟮ뎣볻뗄탅뗀쒣횵쟷뷼폚쇣쟒랽닮뷏킡뗄헽첬럖늼쇭췢떱룃싫싫욬뗄탍떫뛔LPI뛸퇔쫇ퟮ뮵뗄쟩뿶뾼싇떽DSSS쾵춳춨뎣쎿튻룶퇹횵뇭쪾쿠뛔잰튻룶퇹횵뗄탅뫅쿠캻뇤뮯쪱닺짺뚼쫇릤ퟷ퓚뢺탅퓫뇈뮷뺳훐틲듋볙짨뛔솽룶쾵춳뗄LPI뗄샛볓싫탲쇐닢솿뚼쫇퓚510dB뗄탅퓫뇈쳵볾쿂뷸탐솽룶쾵춳c(t)붫쫇쇣뻹횵뗄헽첬럖늼떫랽닮튪뇈틔샛볓잰튪듳탭뛠뛔폚뒫춳뗄DSSSBPSK틑뗷탅뫅뛸퇔뗄삩욵퓶틦뚼짨캪100놶20 dB떱싫욬횵룄뇤쪱잡뫃쫇180뗄쿠틆뛸헢훖탂뗄뛠뗧룹뻝틔짏럖컶컒쏇샻폃SystemView쾵춳럂헦죭볾욽삩욵싫퓲냑쿠캻뮻뇤돉튻룶솬탸맽돌평폚쿠캻틔2뛔짏쫶솽룶쾵춳뗄LPI뷸탐쇋럂헦룹뻝믹듸뗈킧풭샭캪훜웚틲듋뿉붫랶캧뗄헽첬쿠캻럖늼쪹폃쇋뷏뗍뗄쫽뻝싊뫍싫쯙싊틔복짙볆쯣믺뗄퓋쯣솿뫍뮻돉[02]랶캧뗄뻘탎럖늼떱룟쯙삩욵싫춨맽뗍춨싋늨럂헦쪱볤떫헢늢늻펰쿬쾵춳뗄탔쓜뫍럂헦뷡맻[4][5]틲욪웷쪱뿉쓜믡틽웰싫욬쿠맘쳘탔뗄쒳훖틀삵탔떫쫇쯹럹쯹쿞SystemView쾵춳럂헦죭볾뗄춼럻쒣탍솬쿟춼퓚듋닉폃뗄뗍춨싋늨웷뻟폐쿠뛔뷏뗍뗄뷘횹욵싊퓲닺짺뗄헢쪡싔놻뇈뷏뗄솽룶쾵춳훐퓘늨욵싊뚼짨캪 300 Hz쫽훖틀삵탔늻듳뛠뗧욽삩욵싫죔좻쓜놣돖폐솼뫃뗄ퟔ쿠맘뻝싊캪1 Hz쾵춳닉퇹싊캪3000 Hz뛔뎣맦BPSK뗷훆쳘탔죧춼2쯹쪾뗄럂헦뷡맻헢쮵쏷뺭룃탅뫅뗷훆뗄쾵뗄DSSS쾵춳닉폃뛾뷸훆PN싫뗄싫쯙싊캪100 Hz탂탍춳죔좻폫뒫춳뛾뷸훆PN뗷훆뗄쾵춳튻퇹죝틗춬늽[2][3]캪삩욵싫뗄룟쯙PN싫뗄싫쯙싊캪800 Hz뗍춨싋늨웷톡폃놣횤쫕랢솽뛋뛠뗧욽삩욵싫랢짺웷뗄튻훂탔뗍춨싋늨웷튻룶듸뿭캪룟쯙PN싫쯙싊냋럖횮튻100 Hz뗄9뷗웵뿉틔닉폃쫽ퟖ쪽싋늨웷믲짹뇭쏦(SAW)싋늨웷살쪵쿖뇈톩럲뗍춨싋늨웷ퟨ듸쮥복캪80 dB춼3뫍춼4럖뇰뇭퓚랢짤믺뛋룃삩욵싫춨맽뿘훆튻룶쿠캻뮻웷살쪵쿖뗷훆춬퇹퓚뷓쫕믺뛋튲쪹폃쿠춬삩욵싫틔쿠랴뗄쿠캻쪾쇋탂쾵춳폫뎣맦쾵춳틑뗷탅뫅횮볤뗄욵웗닮뇰춼5뫍춼6럖뇰쫇탂쾵춳뫍뎣맦쾵춳뗄틑뗷탅뫅뺭맽뮻살쪵쿖뷢삩샭싛짏룃뗷훆랽램돽삩욵싫늻튻퇹췢욽랽볬늨웷뫳뗄욵웗춼뿉틔맛달떽뎣맦뗷훆쫤돶뗄탅뫅-250 0 250 500Power Spectrum of new PN (dBm 50 ohms)0 500 1e+306RealPo-20Awemp4r-40litudBdem-6000200000-800-250 0 250 5000 500 1e+3Frequency in Hz(dF=-3 Hz)Frequency in Hz(dF=-3 Hz)SystemViewSystemView춼2 뛠뗧욽삩욵싫뗄ퟔ쿠맘쳘탔럂헦뷡맻춼3 뛠뗧욽삩욵싫틑뗷탅뫅욵웗
• 960 •쾵 춳 럂 헦 톧 놨 2002쓪7퓂Power Spectrum of mod out (dBm 50 ohms)Power Spectrum of new xA2 (dBm 50 ohms)0 250 500 7500 500 1e+300Po-20we-20r-40dB-40m-6000-60-80-80-0 500 1e+30 250 500 750Frequency in Hz(dF=-3 Hz)Frequency in Hz(dF=-3 Hz)SystemViewSystemView춼4 뎣맦DSSSBPSK삩욵탅뫅욵웗춼5 뛠뗧욽DSSS삩욵탅뫅욽랽뫳뗄욵웗Power Spectrum of xA2 (dBm 50 ohms)Power Spectrum of new dalay (dBm 50 ohms)0 500 1e+30 500 1e+300Powe-20Pow-20rer-40dBdB-40mm-600000000-60-80-80-100 0 500 1e+30 500 1e+3Frequency in Hz(dF=-3 Hz)Frequency in Hz(dF=-3 Hz)SystemViewSystemView춼6 뎣맦DSSSBPSK탅뫅욽랽뫳뗄욵웗춼7 뛠뗧욽DSSS삩욵탅뫅뺭맽뇈쳘퇓동쿟볬늨웷뫳뗄욵웗춨맽욽랽볬늨웷뫳퓚600Hz뒦뿉뗃떽쓜솿뷏캪벯훐뗄튻룹Power Spectrum of Sink 14 (dBm 50 ohms)웗쿟뛸퓚탂쾵춳뗄쫤돶탅뫅훐좴놻틖훆뮻퇔횮웤쓜0 500 1e+3솿룼럖즢폐샻폚쳡룟LPI탔쓜춼7뫍춼8룸돶쇋솽훖0쾵춳쫤돶탅뫅춨맽뇈쳘퇓동쿟볬늨웷뫳뗄욵웗뿉틔맛달떽탂쾵춳뗄쫤돶욵웗틖훆쇋뎣맦쾵춳훐솬탸돶쿖뗄샫즢럥횵웗Pow-20er쿟럂헦쫽뻝쿔쪾헢훖탂뗄삩욵탅뫅쳥훆룼쓑놻뗐랽뗄볠닢dB웷쯹뷘믱m-400000-604 뷡싛-80 놾컄헫뛔뎣맦DSSSBPSK뗷훆훐듦퓚뗄LPI틾뮼0 500 1e+3쳡돶쇋튻훖뻟폐솼뫃LPI탔쓜뗄DFrequency in Hz(dF=-3 Hz)SSS뗷훆탂랽램룃랽SystemView램닉폃뛠뗧욽삩욵싫뷸탐솬탸쿠캻뗷훆퓚뗷훆듸뿭늻뇤춼8 뎣맦DSSSBPSK삩욵탅뫅뺭맽뇈쳘퇓동쿟볬늨웷뫳뗄욵웗뗄쳵볾쿂뷢뻶쇋뒫쫤탅뫅죝틗놻욽랽볬늨웷뫍뇈쳘퇓동IEEE Letters, 1997, 33(1): 37-38.볬늨웷헬닢뗄컊쳢늢춨맽SystemView쾵춳럂헦죭볾럂헦[3] Agee B G, Kleinman R J, Reed J H. Soft Synchronization of Direct퇩횤쇋퓚쿠춬듸뿭뫍릦싊쳵볾쿂탂쾵춳뇈뎣맦BPSK뗷Sequence Spread Spectrum Signals [J]. IEEE Transactions on훆뗄DSSS쾵춳뻟폐룼뫃뗄LPI탔쓜Communications, 1996, 44(1): 2234-2237.[4] 싞컀뇸, 쯯, 헅뷝. SystemView뚯첬쾵춳럖컶벰춨탅쾵춳럂헦닎뾼컄쿗:짨볆[M]. 컷낲: 컷낲뗧ퟓ뿆벼듳톧돶냦짧, 2001.[5] 쟠쯉, 돌쯉, 커붨뮪. 쫽ퟖ춨탅쾵춳뗄SystemView럂헦폫럖컶[1] Dixon R C. Spread Spectrum Systems with Commercial Applications[M]. 놱뺩: 놱뺩몽뿕몽쳬듳톧돶냦짧, 2001.(3rd edition)[M]. John Wiley & Sons, Inc. 1994.[2] Dominique F, Reed J H. A Simple PN Code Sequence Estimation andSynchronization Techniques Using the Constrained Hebbian Rule [J].짏뷓뗚957튳of continuous time fuzzy control systems [J]. Int J Systems Science,[5] 쯯퓶?. 훇쓜뿘훆샭싛폫벼쫵[M]. 놱뺩: 쟥뮪듳톧돶냦짧, , 27(2): 193-203.[6] Xiao-Jun Ma, Zeng-Qi Sun, Yan-Yan He. Analysis and Design of[4] 룟컀뮪, 킻붣펢. 샫즢탍쒣뫽쾵춳뗄컈뚨쿟탔볠뚽뿘훆웷짨볆[J].Fuzzy Controller and Fuzzy Observer [J]. IEEE Transactions on탅쾢폫뿘훆, 2000, 29(4): Systems, 1998, (6): 41-51.
