Effective rate maximization in large MIMO multiuser system

Large MIMO system can achieve high data rate with simple linear transceiver. However, for this advantage, long time is required to estimate channel state information (CSI) at base station (BS). When estimation time is not negligible in coherence time, there exists tradeoff between estimation and data transmission. With long estimation time, data rate increases, but data transmission time decreases. Otherwise, with short estimation time, data rate decreases, but data transmission time increases. Therefore, maximizing not data rate itself but effective rate is required in large MIMO system. We mathematize an effective rate problem in a reasonable large MIMO system, and prove its concavity and find the optimal tradeoff point.