Capacity-aware linear MMSE detector for OFDM-SDMA systems

This paper presents a capacity-aware linear minimum mean square error (MMSE) detector for orthogonal frequency-division multiplexing/space-division multiple access (OFDM-SDMA) applications. We derive closed-form expressions for the signal-to-interference plus noise ratio (SINR) performance of OFDM-SDMA systems with linear MMSE detection method, where capacity enhancements have been introduced in the transmit/receive weight computations. Using the derived expressions, we compare the performance of the proposed scheme with the regular multiple-input multiple-output (MIMO)-MMSE system in OFDM-SDMA applications. It is shown that in enhancing the system capacity, the capacity-aware MIMO-MMSE scheme also enhances the SINR, resulting in lower symbol error rate (SER) compared to the conventional MIMO-MMSE beamforming schemes.