qpsk 的调制模式的模拟 分别在AWGN和rayleigh 两种情况下的ber 性能-qpsk modulation mode simulation of the ber performance in AWGN and rayleigh two kinds of circumstances

QPSK MODUALTION WITH HELICAL INTERLEAVING of OFDM sysytem BER-bit error rate analisys. and trying to improve more BER