使用半分析半仿真的方法进行QPSK系统仿真，分别计算在高斯信道、瑞利衰落信道、莱斯信道环境下的系统误比特率（BER）-Simulate a QPSK system(without coding), write a summary report in MS Word file containing the following items together with the necessary analysis & discussions.

system diagram

error performance(BER-EbNo curve) under

　 (1) AWGN channel,

　 (2) Rayleigh fading channel, and

　 (3) Ricean fading channel.

　 All BER-EbNo curves should be drawn in one figure with the same scaling, together with the theoretical AWGN performance. Please set channel and system parameters by yourself

discuss the impact of different channels.