Limited Feedback for MU-MIMO Systems with One-Bit ADCs

Abstract

This paper considers a multi-user multiple-input multiple-output (MU-MIMO) system with one-bit analog-to-digital converters. In this system, a novel limited feedback method for transmit precoding is proposed. The key idea of the proposed feedback method is to use a coding theoretical approach. By converting the MU-MIMO system into the equivalent parallel binary symmetry channels, a receiver constructs multiple precoded-channel-dependent codebooks using both the estimated channel from pilot transmissions and predefined precoding matrices. Then, it sends back the index of the best precoding matrix that maximizes a lower bound of the correct detection probability, which is proportional to the maximum of minimum Hamming distances of the codebooks. One interesting observation is that the proposed method provides a significant gain in terms of bit-error-rates compared to open-loop transmission, even with a few bits feedback under certain antenna configurations.