Advanced receivers for downlink MIMO in LTE network

In MIMO LTE Networks, closed loop link adaptation together with precoding matrix selection try to reduce the interference at the receiver side while maximizing the data rate for a given QoS. However, due the constraints of limited feedback and finite size precoding codebooks, the residual spatial layer interference remains a major impediment to reach high spectral efficiency. The aim of this paper is to evaluate for LTE downlink both at link and system levels the potential gain of non linear receivers with respect to their Linear Minimum Mean Square Error (LMMSE) counterpart. Within the considered 4×4 MIMO LTE network, adopting a Cyclic Redundancy Check (CRC) based Successive Interference Cancellation receiver potentially improves the average rate by 5% and 10% in peak and off-peak traffic hours, respectively. However, the interference-free upper bound promises a gain of 45% and 60% for the same load conditions. These results militate for the adoption of more sophisticated receivers, e.g., turbo-SIC, for large MIMO systems.