Accurate BER Analysis of Asynchronous DS-CDMA Systems in Ricean Channels

— The accurate Bit Error Rate (BER) calculation of an asynchronous Ricean-faded DS-CDMA system using random spreading sequences and BPSK modulation is studied in this paper. A new closed-form expression is derived for the conditional characteristic function of the cochannel interference. Furthermore, a new BER expression involving only a single integration is derived invoking the characteristic function approach and hypergeometric functions of two variables. The accuracy of our BER expression is confirmed by our simulation results for various spreading sequence lengths and various Ricean K-factors. By contrast, the Standard Gaussian Approximation (SGA) overestimates the BER of Rayleigh fading channels, when there is no Line-of-Sight (LOS) component and it under-estimates the BER, when the LOS component becomes stronger.

• Type: Conference
• Year: 2006
• Where: VTC
• Authors: Xiang Liu, Lajos Hanzo
• Keywords: BER Expression, Characteristic Function, Spreading Sequence, VTC 2006