Comparison of CS-CDMA and MC-CDMA : BER and PAPR

In this paper, a cyclic prefix code division multiple access (CP-CDMA) system with the use of comb spectrum (CS) code, so called CS-CDMA, is described and a comparison between the CS-CDMA and the Multi-carrier code division multiple access (MC-CDMA) is implemented in terms of the bit error rate (BER) performance and peak to average power ratio (PAPR). The two systems have a very similar spectrum property: each userpsilas signal is spread over one part of the whole bandwidth, so they can obtain the same frequency diversity gain and have similar BER performances. However, the direct spreading is applied in time domain for CS-CDMA and frequency domain for MC-CDMA. This follows the difference of the signal envelop distribution and as a result, different PAPR in the two systems. Therefore, we study the PAPR distributions and evaluate the BER performances through computer simulations for the both systems with different active user numbers.