BER performance of a direct-sequence CDMA system in multipath fading mobile radio channels with Rake reception

The performance of an asynchronous DS CDMA system for communications over multipath fading mobile radio channels using an N-path Rake receiver is investigated. Multipath power delay profiles for typical urban, hilly terrain and rural areas which are derived from those specified for the GSM system have been used to assess the robustness of the CDMA system against frequency-selective fading. The effect of interference on the system performance is also investigated for the three multipath environments. Furthermore, the authors evaluate the performance of a single path-lock correlation receiver and compare the results obtained with that of the Rake multipath combining receiver for a spreading bandwidth of 1.27 MHz. The effect of spreading bandwidth allocation on the diversity performance of the Rake system in the urban channel has also been investigated. The criterion of the system performance is the average bit-error rate (BER) as a function of the signal-to-noise ratio (SNR)