A dual N-ary orthogonal hybrid modulation system is introduced in this paper,which can increasethe data rate greatly compared with conventional N-ary orthogonal spread spectrum system,so it can beused for high rate data communication.Then,three code recognition algorithms are presented for dual N-ary orthogonal hybrid modulation system and the analytic bit error rate(BER)performance of the systemin additive white Gaussian noise(AWGN)and flat Rayleigh fading channel is derived.Finally,the com-puter simulation of the system with three code recognition algorithms is performed,which shows that thesimplified maximum a posteriori(MAP)algorithm is the best for the system with a compromise betweenthe performance and the complexity.
针对N进制正交扩频和MDPSK复合调制(N O rth-MDPSK),分析了单径慢衰落信道模型中带有频差时的误比特率。首先运用全概率定理和马尔可夫链,建立了性能分析的统一框架;在此框架下,推导了AW GN、瑞利衰落和N akagam i-m衰落信道中的误比特率公式。数值结果表明,与单纯N O rth相比,N O rth-MDPSK以较低的性能损失代价,提供了更高的带宽效率。
