双极性(Q,) Ψk S(1)=Acos(@t+) +1,+1 元/4 -1,1 3π/4 -1,-1 -3π/4 冬QPSK相位转移图 +1,-1 -元/4 1,anan-1=1,1;S S()-Aco( -11 2,a,an1=1,-1:S0)=Acos(@t-7) 3π 3,a,an1=-1,-15S0=Acos@1- 4.d.d=-1,l:S0)=Aco() 1-1 (a) 相位突变π-11 11 -1-1 1-1 QPSK相位转移图 1 1, 1,1 n n a a ; ( ) cos( ) 4 c St A t 1 2, 1, 1 n n a a ; ( ) cos( ) 4 c St A t 1 3, 1, 1 n n a a ; 3 ( ) cos( ) 4 c St A t 1 4, 1,1 n n a a ; 3 ( ) cos( + ) 4 c St A t 相位突变π St A t cosc k 双极性(Q,I) ψk +1,+1 π/4 -1,1 3π/4 -1,-1 -3π/4 +1,-1 -π/4