Bit error probability analysis of linear receivers for CDMA systems

Bit error probability of linear receivers for multiuser communications is analysed. The results can be applied both for centralised multiuser or joint receivers as well as for decentralised single-user receivers. The analysis is presented for AWGN and known or perfectly estimated fading multipath channels. The analysis is also extended to the estimated fading multipath channel case with data-aided (DA) channel estimation. Two ways to approximate the averaging over the interfering data symbol combinations are considered and compared. One is a semi-analytic method, where only part of the interfering data symbol combinations are taken into consideration in the averaging. The other is the Gaussian approximation. In addition to MAI, the analysis directly incorporates the impact of the interpath interference (IPI) or inter symbol interference (ISI) to the receiver performance. Numerical examples are presented to demonstrate the usefulness of the method.