Extrinsic Information Analysis of a New Iterative Method Using the Stair Matrix for Massive MIMO Uplink Signal Detection

In this letter, we have proposed a new convergence model to account for both symbol detection and soft-output derivation. In the new convergence model, the extrinsic information analysis is conducted. Through extrinsic information analysis, we have validated the performance superiority of a new iterative method using the stair matrix in the development over the existing near linear minimum mean-square error detection proposals. The extrinsic information analysis also reveals a significant performance loss of the existing proposals. We have evaluated the system bit error rate performance and the results are consistent with the extrinsic information analysis.