Medium-precision ADC quantization error modeling for MIMO-OFDM

Abstract Analog-to-digital converter (ADC) is an indispensable application for wireless communication systems, but the model of the quantization error induced by ADC is still an open interdisciplinary problem. This paper proposes a general framework of quantization error model for multiple-input multiple-output (MIMO) system employing orthogonal frequency-division multiplexing (OFDM) with medium-precision ADCs. The Gaussian mixture model (GMM) is used to represent the error caused by ADCs, and then an optimization structure is constructed. In the proposed optimization method, with the key parameters of the error distribution obtained by the expectation-maximization (EM) algorithm, the generalized approximate message passing (GAMP) algorithm can detect the data accurately. The simulation demonstrates that the proposed quantization error calculation algorithm can improve the performance of data detection under imperfect channel state information (CSI).