Evaluation of PMI Feedback Schemes for MU-MIMO Pairing

The status of codebook based MU MIMO feedback schemes in different wireless standards are briefly overviewed. Based on the Normal Feedback Scheme to feedback the preferred Precoding Matrix Index (PMI), a Best Companion Pairing (BCP) scheme and a Best Companion Cluster (BCC) scheme are introduced to make more efficient pairing. Besides the preferred PMI, UE need to feedback more PMIs for the BCP scheme or a cluster index for the BCC scheme to minimize the intracell or intercell interference. System level simulation results show that the BCC scheme can make a reasonable tradeoff between feedback overhead and throughput.