- Journal Article
Rights / licenseIn Copyright - Non-Commercial Use Permitted
Massive multiuser (MU) multiple-input multiple-output (MIMO) is foreseen to be one of the key technologies in fifth-generation wireless communication systems. In this paper, we investigate the problem of downlink precoding for a narrowband massive MU-MIMO system with low-resolution digital-to-analog converters (DACs) at the base station (BS). We analyze the performance of linear precoders, such as maximal-ratio transmission and zero-forcing, subject to coarse quantization. Using Bussgang's theorem, we derive a closed-form approximation on the rate achievable under such coarse quantization. Our results reveal that the performance attainable with infinite-resolution DACs can be approached using DACs having only 3-4 bits of resolution, depending on the number of BS antennas and the number of user equipments (UEs). For the case of 1-bit DACs, we also propose novel nonlinear precoding algorithms that significantly outperform linear precoders at the cost of an increased computational complexity. Specifically, we show that nonlinear precoding incurs only a 3 dB penalty compared with the infinite-resolution case for an uncoded bit-error rate of 10 -3, in a system with 128 BS antennas that uses 1-bit DACs and serves 16 single-antenna UEs. In contrast, the penalty for linear precoders is about 8dB. Show more
Journal / seriesIEEE Transactions on Communications
Pages / Article No.
SubjectMassive multi-user multiple-input multiple-output; Digital-to-analog converter; Bussgang's theorem; Minimum mean-square error precoding; Convex optimization; Semidefinite relaxation; Douglas-Rachford splitting; Sphere precoding
Organisational unit09695 - Studer, Christoph / Studer, Christoph
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