改进时变多径信道下OFDM系统性能分析

Performance evaluation of OFDM system under modified time-varying multipath Rayleigh fading channels

为了更加精确地描述移动无线通信信道的时变多径特性,对传统的时变多径信道模型进行了改进,基于维纳过程将多径相位分量建模为时间变量,从理论上对经历时变多径信道的OFDM系统接收信号分量进行分析与计算,推导了系统的误码率,并对理论值与仿真结果进行了对比.结果表明:与传统信道模型相比,改进信道模型的衰落自相关谱和OFDM系统误码率与仿真结果更为相符,证实改进的信道模型能更准确地描述时变多径衰落信道.

To describe the time-varylng characteristic of wireless channel accurately, the effect of fluc- tuation in the component phases was considered and a modified time-varying multi-path channel was proposed. Then, the performance of orthogonal frequency division multiplexing （OFDM） signal over the proposed channel was analyzed theoretically. By calculating the components of the received signal, the symbol error rate （SER） was achieved. Simulation results show that the fading autocorrelation of the modified channel march better with simulated results compared with traditional channel model. The SER of OFDM system was also considered. And results show that the modified channel model can describe the time-varying multi-path channel accurately.