Early-Stopping for RAKE Receivers

In this paper, a statistical method to reduce the computation in a spread-spectrum RAKE receiver is proposed. The fundamental idea is to stop the integration of the received signal during despreading earlier than in the conventional RAKE, when the intermediate integrated output is greater than a predefined threshold. With minimal changes in RAKE implementation, this technique can provide at least 40% savings in the number of chips to be integrated with BPSK transmission at 7 dB of SNR. We present the analysis on the performance of the proposed scheme for a single finger case, and extend the result to a multi-finger RAKE. The simulation results under Rayleigh multi-path fading channel show that there can be computation savings between 60% and 80% depending on the channel profile