Improved RAKE receiver using finger variance weight

The RAKE receiver is one of the most critical subsystems for CDMA communication systems. The RAKE receiver is used to combat multipath channel fading by using multiple fingers each targeted at a path of different delay and then soft-combine the signals from different fingers together. The “soft” combination at the RAKE receiver presents the intrinsic diversity gain spread over different paths. Usually, a traditional RAKE receiver combines the signals from different fingers based on the weights that are proportional to the measured pilot strengths at different fingers. This paper proposes using weights that are the ratios of the measured pilot strength to the measured variance at different fingers. By using the proposed weights, the performance of RAKE receiver can be improved up to 0.9 dB. An analytical methodology is derived to assess the performance. The performance improvement is reflected directly to the system capacity and system throughput