跳时M元双正交脉冲位置调制超宽带通信性能研究

针对目前超宽带（UWB）通信调制方式传输效率低下、误码率过高的问题，提出了采用跳时M元双正交脉冲位置调制（TH—MBPPM）改善系统性能的方法．TH—MBPPM方法将需要传送的多个信息比特分别调制到信号的幅度和位置上，同时在信号中加入伪随机跳时码，解调端采用概率密度函数的方法对各匹配滤波器输出端的多址干扰成分进行精确的计算，将所有干扰信号建模为高斯白噪声并根据最大似然准则对接收的信号进行判断，得到了系统误符号率的封闭表达式及其简化的计算表达式，该表达式精确地反映了系统的误符号率性能且计算复杂度较低．与跳时M元正交脉冲位置调制UWB通信系统相比，TH-MBPPM方法误符号率更低，且系统复杂度降低了50％。

Performance Analysis of Ultra-Wideband Communication System with Time-Hopping M-Ary Biorthogonal Pulse Position Modulation

Focusing on the problem that the low transmitting efficiency and the high bit error rate of the current modulation techniques existed in ultra wideband(UWB) communication system,a time-hopping Mary biorthogonal pulse position modulation(TH-MBPPM) scheme was proposed.TH-MBPPM scheme modulated the multiple information bits which needed to be transferred to the signal's amplitude and position respectively,at the same time the pseudorandom time-hopping code was added to the signal.The multiple address interference of the output of each matching filter was accurately calculated utilizing the probability density function technique in demodulator point,then all the interference was modeled as white Gaussian noise and the received signal was estimated based on the maximum-likelihood criterion,later the closed-form expression of symbol error rate(SER) and its simple expression were provided.The expression reflects the system SER performance accurately and its computational complexity is relatively low.Compared to the UWB communication system of time-hopping M-ary orthogonal PPM,TH-MBPPM technique has lower SER and the complexity of the system is decreased by 50%.