Pilot symbol aided adaptive receiver for Rayleigh faded CDMA channels

Recently a number of modified MMSE receivers have been efficiently applied to code-division multiple-access (CDMA) communications with dynamic fading channels. These receivers can successfully cope with multiple access interference (MAI) but are limited to BPSK signals. This paper presents new adaptive implementations of MMSE receivers for higher order signals in multi-user environments. High-order signal constellations, e.g. MQAM, have been extensively investigated in single-user fading channels due to their high spectral efficiency. This paper provides performance evaluations and analysis for the proposed adaptive multiuser receiver. It also presents a new computationally efficient adaptive algorithm for these high-order signal constellations