Rake接收机在超宽带系统中的均衡性能分析

Channel equalization performance of rake receiver in UWB systems

从缩短信道时延扩展的角度出发,研究了Rake接收机的部分信道均衡能力,并推导出了Rake接收机均衡性能与Rake接收机的复杂度和信道衰减系数之间的关系;分析了信道估计误差对Rake接收机合并前后多径信道变化的影响。研究表明当存在估计误差时,Rake接收机仍然能实现均衡的作用,但是性能有所下降;由于低复杂度Rake接收机引入的估计误差较少,在低信噪比条件下其均衡性能甚至会优于高复杂度的Rake接收机。

Rake receiver was analyzed for its performance of channel shortening by deriving the delay spread of an equivalent channel after maximal-ratio combination. Both the relationship between the partially equalization performance of Rake receiver and the number of its taps, and the influence of channel estimation error on channel shortening performance were investigated. From the analysis, it＇s indicated that Rake receiver can still shorten the channel with channel estimation error, but there will be some extent of performance degradation. Moreover, the channel equalization performance of Rake receiver with lower complexity outperforms that with higher complexity in low SNR since less estimation error is introduced into Rake receiver with small number of taps.