移动无线传感器网络系统在n-Rayleigh信道下的性能分析

在n￣Rayleigh信道下，研究了使用选择合并( SC)接收的移动无线传感器网络系统的平均符号误码率( ASEP )和信道容量。基于矩生成函数( MGF)方法，推导了系统采用相干检测的相移键控调制( PSK)，正交幅度调制( QAM)，脉冲幅度调制(PAM)等数字调制方式的ASEP的精确表达式。同时，也得到了系统信道容量的精确表达式。然后对不同条件下的ASEP和信道容量性能做了数值仿真，理论分析结果与仿真结果相吻合，验证了理论分析结果的正确性。仿真结果表明：随着分集支路数的增加，系统的ASEP和信道容量性能得到了很好的改善，当使用QPSK调制，信噪比为16 dB时，分集支路数L＝1，系统的误码率是6×10－2，信道容量是4(bit/s)/Hz；分集支路数L＝2，系统的误码率是1×10－2，信道容量是5.1(bit/s)/Hz；分集支路数L＝3，系统的误码率是2×10－3，信道容量是5.8(bit/s)/Hz。

Performance Analysis of Mobile Wireless Sensor Network Systems Under n-Rayleigh Fading Channels

The average symbol error probability(ASEP)and channel capacity of the mobile wireless sensor network system employing selection combining( SC) receiving under n￣Rayleigh fading channels is investigated in this paper. Based on the moment generating function( MGF) approach,the exact ASEP expressions are derived for several mod￣ulation schemes,including phase shift keying modulation ( PSK),quadrature amplitude modulation ( QAM),and pulse amplitude modulation( PAM) . The exact channel capacity expressions are also presented. Then the ASEP and channel capacity performance under different conditions is evaluated through numerical simulations. The numerical simulation results coincide with the theoretical results well,and the accuracy of the analytical results is verified. Simulation results show that:the ASEP and channel capacity performance can be improved with the diversity bran￣ches increased,when SNR=16 dB,the diversity branches L=1,the ASEP with QPSK is 6×10-2,the channel capac￣ity is 4 (bit/s)/Hz;the diversity branches L=2,the ASEP is 1×10-2,the channel capacity is 5.1 (bit/s)/Hz;the diversity branches L=3,the ASEP is 2×10-3,the channel capacity is 5.8 (bit/s)/Hz.