In this paper, we investigate a new generalized selection combining (GSC) technique and an adaptive rake combining scheme to save the power consumption of mobile rake receivers for wideband CDMA systems. The new GSC technique called minimum selection GSC (MS-GSC) selects a minimum number of rake fingers, while maintaining the combined SNR larger than a given threshold. The proposed adaptive rake combining scheme dynamically adjusts the threshold value to maintain the desired BER. Therefore, our rake combining scheme can be integrated into any GSC, which select fingers based on a given threshold value. The proposed MS-GSC shows a low standard deviation in bit error statistics and is advantageous in practical implementation. Our experiments indicate that the proposed adaptive combining scheme reduces the power consumption of a mobile rake receiver up to 67.8 % by turning off unselected rake fingers.
Suk Won Kim, Dong Sam Ha, Jeffrey H. Reed