Low complexity V-BLAST for massive MIMO with adaptive modulation and power control

We consider the performance of a low complexity Vertical Bell Laboratories Layered Space Time system with a maximum ratio combining receiver (LC-VBLAST) in an uplink massive multiple-input-multiple-output (MIMO) deployment with single antenna users. This receiver is known to give a similar error rate performance to zero forcing (ZF) for simple systems while reducing complexity. In this paper, we show that LC-VBLAST remains similar to ZF for more complex adaptive modulation systems and in the presence of channel estimation error, LC-VBLAST can be superior. These results are analytically justified and we derive an exhaustive search algorithm for power control (PC) to bound the potential gains of PC. Using this bound, we demonstrate that LC-VBLAST performs well without the need for additional PC.