Asymptotic analysis of improved linear receivers for BPSK-CDMA subect to fading

In this paper, we design and analyze a new class of linear multiuser detect ors, which can be applied when the users employ BPSK modulation and the fad ing coefficients of the active users are known at the receiver (such as bas e-station demodulation). The tools of asymptotic distribution of the spectr um of large random matrices are used to show that relative to the classical minimum mean-square-error (MMSE) receiver, the output signal-to-noise rati o (SNR) improves by halving the number of effective interferers and adding 3 dB to the input SNR. We also propose sensible approximations to the propo sed linear receivers so as to facilitate their use in CDMA systems that emp loy long codes.