【摘要】 假设复振幅估计是理想的,研究了宽带CDMA(移动通信多址技术)移动通信系统中路径搜索和延迟估计对RAKE接收机性能的影响.采用3GPP建议的幅度和相位恒定、路径延迟跳变的Birth-death动态信道模型,用稳健实用的时域相关方法进行了路径搜索和延迟估计,考察了3GPP下行专用物理信道(DPCH)的性能,得到了路径跳变/不变、不同估计窗长时的路径捕获率、延迟估计值概率分布和链路误块率.结果表明,延迟估计的非理想使性能下降2.3～5.0dB,交织对性能的贡献大于1dB(路径不变)或2dB(跳变),估计窗长的选择应综合考虑噪声滤除和路径跟踪能力.更多还原

【Abstract】 The impact of path searching and delay estimation on the performance of RAKE receiver was investigated, assuming ideal estimation of the amplitude and phase of radio propagation channel. Birth-death dynamic channel model recommended by 3GPP was employed, with invariant amplitude and phase as well as hopping paths. Simple and robust correlation method was used to search path and estimate time variant path delays. Link performance of 3GPP downlink dedicated physical channel was studied. The probabilities of path acquisition and delay estimates as well as the block error rates were obtained, under the conditions of fixed paths/hopping paths and various estimating window lengths. The results show that the non-ideal path delay estimation degrades the link performance 2.3～5.0 dB, interleaving contributes more than 1 dB (fixed paths) or 2 dB (hopping paths) improvement to link performance, and the estimating window length should be selected upon the compromise of noise reduction and path tracking.更多还原