Increasing the uplink user capacity with multiple antennas at the receiver

In the absence of the orthogonal design and a very low coding rate channel code, a new bandwidth-efficient multi-user scheme is proposed, which considers random interleavers for different users and multiple antennas at the receiver. Turbo processing is exploited based on the minimum mean square error (MMSE) soft-input soft-output (SISO) detector with interference cancellation (IC) to obtain the receive diversity. The simulation results show that when the number of users K is no more than the product of the number of receive antennas and the reciprocal of the coding rate, the proposed scheme can achieve the single-user performance, which indicates that the uplink user capacity of wireless networks can be dramatically increased with the proposed scheme when more antennas are implemented at the receiver. Meanwhile, it provides a solution to dealing with underdetermined multiple input multiple output (MIMO) systems.