5.6 Binary Baseband: BPAM (antipodal,unipolar),Orthogonal signaling; Passband: BPSK, OOK or BASK, BFSK(Orthogonal) M-ary,1-D signaling Baseband:MPAM Passband: MASK M-ary,2-D signaling (Passband) MPSK, QAM UESTC-Digital transmission through the AWGN channel Prof李晓峰 2
5.6.3 MPSK {,an} {,an,} MPSK (Carrier-phs) s(t) r(t)= Recv s (t)+n(t) In many simple 1,2.Ml case the gr(t)is a rect pulse,and the The signals:s()=gr()cos x+ A MF-ML receiver is given by, MF is equivalent to an integrator. =Ang()cos2πfc1-Ang()sin2πfl r() ←cos2对l Min- (gcos2. Dist The basis: %0=是，0si如2 Prob of err is computed by, r(t) ⑧8(T-0 L=T Two sync demod.that requires: c0s2河 The local cos/sin are coherent with the carriers in recv sig. 。 The sampler/integrator is synchronous with the symbols in recv sig. UESTC-Digital transmission through the AWGN channel Prof李晓峰 3
5.6.3 MPSK Unfortunately,the LO has phase ambiguities and DPSK is often employed for solution. DPSK Sym Abs-mapping:Relative mapping:A0 MPSK Instead of absolute phase-mapping 0 0 0 (Carrier-phs) π2 π/2 of info sym,PSK with differential 2 π π 1,2,ML-- phase-mapping is called DPSK. 3 3π/2 3π/2 1 The signals:s()=gr()cos 00 =Amg(I)cos2πf1 Min- 2 The basis: %0-28,0cos2 Dist %0=是,0sm2 Prob of err is computed by, r(t) 1=T Two sync demod.that requires: c0s21 The local cos/sin are coherent with the carriers in recv sig. r→⑧8，T- The sampler/integrator is synchronous with the symbols in sin2ft recv sig. UESTC-Digital transmission through the AWGN channel Prof李晓峰 4
5.6.3 MPSK Unfortunately,the LO has phase ambiguities and DPSK is often employed for solution. DPSK Sym Abs-mapping:Relative mapping:A0 MPSK Instead of absolute phase-mapping 0 0 0 (Carrier-phs) 1 π/2 π72 of info sym,PSK with differential 2 π π 1,2.,ML-- phase-mapping is called DPSK. 3 3m/2 3π/2 0 The signals:s()=gr()cos 00 =Amg(I)cos2πf1 -cos4 Min- 2 %0-28,0cos2 Dist The basis: %0=是,0sm20 Prob of err is computed by, r( →⑧T-0 1=T Two sync demod.that requires: c0s21 The local cos/sin are coherent with the carriers in recv sig. r→⑧8，T-0 The sampler/integrator is synchronous with the symbols in sin2ft recv sig. UESTC-Digital transmission through the AWGN channel Prof李晓峰 5
5.6.3 MPSK {,an} {,an,} MPSK (Carrier-phs) s(t) (T)= Recv s (t)+n(t) 1,2.ML The signals:s()=g()cos x+ A MF-ML receiver is given by, =Am8()cos2πf1-Ang()sin2πf1 r(t) ←cos2对I Min- The basis:() Dist () Prob of err is computed by, 元/M π/M E Let=2πm/M be the angle.of s. Compute arctan(/). The decision rule:select the s whose angle is closest to , UESTC-Digital transmission through the AWGN channel Prof李晓峰 6