Performance comparison of chip matched filter and RAKE receiver for WCDMA systems

The third generation cellular communications standard (UMTS) will be based on wideband code division multiple access technology. In this paper the conventional RAKE receiver architecture is compared to the chip matched filter (CMF). Consider that performance of both RAKE and CMF is highly dependent on the channel impulse response estimate which is typically carried out by a correlation method for the RAKE. The CMF instead allows for the more powerful least squares (LS) method. Indeed, due to the presence of interference and noise, better results are obtained by considering only the coefficients of the channel impulse response with higher amplitude. Hence, two new structures, the reduced chip matched filter (R-CMF) and the selective RAKE (S-RAKE) architecture have been considered. For a typical UNITS environment we compare the performance of CMF, R-CMF and S-RAKE both in terms of signal to estimation error (SER) and bit error rate (BER) and show that R-CMF outperforms both S-RAKE and CMF