Round-off Error Analysis in mMIMO Detector Based on Cholesky Decomposition

In this letter, we propose a new approach to justify a round-off error impact on the performance of a low-precision Massive Multiple Input, Multiple Output (MIMO) detector based on Cholesky decomposition. This decomposition is employed to inverse an ill-conditioned matrix in the linear detector of the Multi-User MIMO receiver operating in the beamspace domain. The proposed method was tested with a half-precision format and validated in realistic scenarios generated by the QuaDRiGa 2.0 channel. Experimental results demonstrate our approach predicts errors very close to those achieved by simulations. The proposed approach can be applied to analyze the resulting round-off error in any other part of the communication system.