Achievable Sum-Rates in MIMO Broadcast Channels with Vector Precoding Techniques Using Coded Modulation

In this paper we establish end-to-end achievable sum-rates of different linear and non-linear pre-processing techniques employing amplitude-shift keying (ASK)-modulation in a flat-fading multiple input multiple output (MIMO) broadcast system with single antenna terminals. The obtained results reveal that the minimum mean square error vector precoding (MMSE-VP) technique achieve close to capacity performance in various system settings. Thus it achieves a loss of merely 2-3 dB compared to the sum-capacity in the mid to high SNR range including the effects of practical system implementations, such as a non-ideal modulation set and a sub-optimal solver at the transmitter. When the SNR is low or when the system experience a small load, simpler pure linear techniques achieve similar performance.