Low complexity receivers for CDMA communications over frequency-selective channels

A number of studies show that multiuser detection in CDMA communications can be performed blindly even in a frequency-selective fading environment. However, the computational cost of these blind approaches is magnitudely higher than that of adaptive MMSE receivers which require knowledge of the desired user's signature waveform. The problem is alleviated by Tsatsanis and Bora (see IEEE Transactions on Signal Processing, 1997) where a low complexity blind algorithm is proposed at the expense of reception performance. We present a totally blind adaptive method which yields near optimum performance with complexity comparable to that of the nonblind MMSE receivers.