Fig. 2
From: Low computational complexity methods for decoding of STBC in the uplink of a massive MIMO system
BER performance of the system by utilizing Neumann series
BER performance is evaluated by changing the order of the Neumann series, i.e., R = 2, 3, 4. The BS is equipped with N = 320 antennas that serves M = 16 users. As it can be seen, the system performance improves with adding more terms to the approximation series and gradually gets closer to the exact inversion performance