SMART ANTENNAS IN WIRELESS SYSTEMS - UPLINK MULTIUSER BLIND CHANNEL AND SEQUENCE DETECTION

Recently, space-division multiple-access (SDMA) schemes [1], [2] have been proposed to increase the capacity of wireless communication syste ms by simultaneously transmitting and receiving multiple co-channel si gnals through different spatial channels, In this paper, we address th e uplink (remote users to the base station antenna array) blind channe l and sequence identification problem for an SDMA system, We show that multiuser blind identification can be accomplished by exploiting the spatial and temporal diversities of an antenna array system, In partic ular, a recursive estimation algorithm is developed to recover multipl e signals from intersymbol interference (ISI) and co-channel interfere nce (CCI) by taking advantage of a special structure of the array outp ut and the finite-alphabet property of digital communication signals, The implementation of the proposed approach in practical applications is discussed, and field experiments have been conducted to demonstrate the effectiveness of the proposed algorithm.