1、2008 M 3 27 null 3 7 ? S S / nullL | 1 M 1 _ / 童null 军null 阮安路(解放军炮兵学院研究生系null 合肥null 230031)K null 1 :L | ( LFM) W B | 8 , | K v + V P r H T s O q bY , r _ V s r ? L o z K , “ S ) . 2 “ S 3 1 M 1 ; ; 3 l m s | : TN95null null D S M : ALFM signals self relevance detecting technology researchTong Jun
2、null Ruan Anlu( Graduate Student Department of Artillery Academy of PLA, Hefei 230031)Abstract: LFM signals is the application of a wide range of a signal system, and the signal characteristics is the largest radar at thesame time can be long range and high range resolution. Typically, radar detecti
3、on stage in the search can be accumulated by thepulse of the radar antenna beam width and scanning speed restrictions. Whenthe target is strong and background noise or the reflecnulltive properties of target itself is weak, in the limited number of pulse it usually can not achieve the demand ratio o
4、f successful detecnullting SNR (signal to noise ratio). This paper shows a method to meliorate the SNR which uses digital autonullcorrelation and autonullcornullrelation technique, and gives the experimental result by testing linear FM signal.Keywords: LFM;figures relevant;envelope;digital receiverT
5、 e : + ( 1982null) , 3 , V 3 , Z _ / b0null null _ a Z 4 W ? Z 1 7 B S 1 , a e a“ d a 0 a a 3 | ) a V $ ? Z , “ v ? “ 9 7 ? Z , = # * a r o a s aM 1 s M / 5 b_ ? Z , 1 y ,+ Y 0 5 , r _ Y 5 X | ,y N 4 l b r F | B 1 , . 1 a | T H , 4 M 1 v b7 3 1 M 1 _ / 3 l “ 1 M 1 ) ,4 | ) T , V 7 | | b | _ l 2 v 1
6、“ , 0 l 2 1 l . 2 “ a l z a 1 p T . 1 % , “ - l “ d ,G L . 2 “ a z 4 l 2 I n , T V . 1 1 p , l 2 | 4 bM 1 ) / Q ) i l ,V K v . 1 , r . 2 Y b/ L | 1 M 1 _ # + a L C a L Z # _ T b1null L | 1 M 1 _ # + 1 M 1 _ r | , n 5 r | 1 M 1 + , _ $ b“ - ,LFM | K | , V ,LFM X $ + r W P b1 M 1 _ / 2 | . 2 + ,Y V 1
7、M 1 r “ . 2 _ Z E b ! | F , x(t)= s(t)+ n(t), null43null 7 ? 2008 M 3 27 null 3 S S / null s(t) | ,n(t) . 2 b 1 M 1 :Rxx (m) = Rss(m) + Rvv(m) + Rsv(m)+ Rvs(m) ( 1)T Rss(m) | 1 M 1 f ;Rvv(m) . 2 1 M 1f ;Rsv(m) | . 2 M 1 f ;Rvs(m) . 2 | M 1 f , T | . 2 M ,5 Rxx (m)= Rss(m)+ Rvv ( m), V , m ! H ,Rvv(m
8、) 0,7 | 1 M 1 f f , m v H ,Rxx(m) L Rss(m)b1. 1null 3 1 M 1 # L C 3 l $ , “ M 1 , 4 | , m m 1 U b 3 l “ - , m 2 U bm 2 AD V “ , 9 V ( ? ( ?/ “ , ) b | $ . 2 , AD ? “ ,G L 3 | ) ? C . 2 | bM 1 = y E L C ,) m 3 U , 4 | / HilbertM / 3 b / :(1) | x ( n) N, p L 1 M1 Rxx(m)b(2) P K L M 1 V M 1 9 i O 3 C ,
9、 1 , ,P , v M= 2 N- 1, B G / T :nv = floor(lg10(N 2- 1)/ lg102+ 0. 95) ( 2)M = 2# nv ( 3)(3) n 5 P y = M 9 =M , M, T X, M | ,T H,i 9 b(4)S :Y= X Hb(5) Y S M = Q M , V M 1 yb(6) 4 | bm 3null 1 M 1 y E L C m1. 2null LFM | + L | V r T 4 :s(t) = 1Trect( tT )ej2null(f 0t+ kt2/ 2) (4) q + :Ui(w) = Ui(w) e
10、jnulli(w) (5)T :Ui(w) = A 2null/ nulli(w) =- (w- w0)22 +null4 q + | , H(w) = conj(Ui(w) , q :U0(w) = Ui(w)H(w) = A 2null e- jwtd0 ,w- w0 % !w2 (6)1 M 1 :u0(t) = 12null&+ !- !U0(w)ejwtdw =12null&w0+ !w/ 2w0- !w/ 2A 2null ejw(t- td0) dw =A2null2null1j(t- td0) ej!w(t- td0)/2 - e- j!w(t- td0)/ 2 ejw0(t-
11、 td0) =A!w2null2nullsin !w(t- td0)/ 2!w(t- td0)/2 ejw0(t-td0) (7)| !w = 2nullB , = 2nullB/, w0 = 2nullf 0 ( 7) V ( B | z , z ) :u0(t) = A B sin nullB(t- td0)nullB(t- td0)ej2nullf 0(t- td0) (8) L = | L , # T (8) | L :u0(t) = A B sin nullB(t- td0)nullB(t- td0)cos2nullf 0(t- td0)(9) | B B :sin nullB(t-
12、 td0)nullB(t- td0) ( 10)m 4 B L r | 1 M 1 f m ,V m V s + bnull44null2008 M 3 27 null 3 7 ? S S / nullm 4null L | 1 M 1 f w L V r T (10) V :LFM | 1 M 1 C f , f + , - 4 dB z | z , B - 13.2 dB( LFM | 1 M 1 + + ) , + | LFM | $ 5 b2null LFM | _ L Z _ TL Z : 3 l z 50 MHz, q 100 MHz,AD Compu Scope8500null8
13、 bit,500 MHz/s,Kv “ z 250 MHz,AD “ bL ! | BL | , | : V l - M q f0= 100, | z PW= 40 s, | q k= 0. 25MHz/ s, l | B | , “ 3 1M 1 , 4 | , T m 5 U bm 5null “ 1 M 1 T LFM | 1 M 1 , y N V | LFM | b_ “ F . 2 , “ . 2 9 v , | C , v L V . 1 S/N - 6 dB, V _ LFM | i bm 6A U S/N= - 6 dB S/ N= - 8 dB H 1M 1 bm 6nul
14、l c . 1 M 1 null null3null 1 M 1 _ Z E | z a , _ | . 1 V r - 6 dB, s | 1 M 1 7 + | b “ S M 1 ) ,y N c H , V W ,i 5 T c H , M 1 ? / Y b 3 l _ L r | 4 , “ 1 M 1 ) , V v v d . 2 Y , V . d M 1 _ Z E , | 1 M 1 7 + | Y , 9 _ T V , Z E LFM | z _ r T b I D1_ , i , 1 , . | _ 9 M . :S ,1990.2 4 , | 0 . _ o 3
15、r o E J. ,1997, 10(3):362null367.3 o .L | 3 s # L C “d J .C r ,1999, 21( 1) :39null43.4f ,f + , R , . “ # J .Y / .2001( 9) :8null11.5KENNY O P, BOASHASH B. T imenullfrequency analysisof backscattered signal from diffuse radar targets J .IEEE ProceedingnullF, 1993, 140(3): 198null208.(上接第29页) , TOA T
16、DOA i 5 , Y V l V f / B M E , B 4 MS 9 b_ T V ? V L M 9 , r 4 b I D1S , . “ d L # J.M Y ,2000, 24(5) :19null22.2OST MANN T K, BELL A E. A data fusion architecturefor enhanced position estimation in wireless networks J . IEEE Communications Letters, 2001, 5 ( 8) :343null345.3 CAFFERY J, STUBER G. Sub
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