RAKE Combining Receiver in Frequency Selective Fading Channels

Aiming at the multipath diversity reception in non-spectrum-spreading system, a RAKEcombining receiver is presented in this paper. The estimate of the transmitted data is obtained by the ⅡR (infiniteimpulse response) equalizer with decision feedback (DF) structure, and each multipath signal can be resumed bythis initial solution. Then the multipath elements in the received signal are obtained, and the components arecombined together using maximal ratio combining (MRC) before the final decision, so RAKE combining receiveris accomplished. The cumulated round off noise phenomenon is eliminated by DF-ⅡR, however, error propagationexists in the decision directed filter. While the signal-to-noise ratio (SNR) can be increased evidently after MRC,the error propagation problem is depressed dramatically in the combining receiver. Simulations show that theproposed algorithm can achieve the performance advantages effectively.