Downlink Performance of a Finite Word Length Implemented Rake Receiver for 3G WCDMA

In this paper, the performance degradation due to the finite word length implementation of the Rake receiver for 3G WCDMA is investigated. The performance in terms of bit error rate (BER) as a function of E_b/N₀ in Rayleigh fading channels using Monte-Carlo computer simulations are carried out for varied word lengths. The performance results are also compared with that of the floating-point simulations. The 8/6/4/2-bit word length implementations are considered in the simulation runs in order to compare their effect on the performance. It is shown that the BER performance with 8-bit word length based implementation of the Rake receiver is similar to that of the floating-point implementation.