A Low-Complexity Multiuser Adaptive Modulation Scheme for Massive MIMO Systems

Yuehao Zhou, Caijun Zhong, Shi Jin, Yongming Huang, Zhaoyang Zhang

Abstract: A novel low-complexity multiuser adaptive modulation (MAM) scheme is proposed for uplink massive multiple input and multiple output systems with zero-forcing detection, which requires only slow-varying large-scale shadowing information for the users. Closed-form expressions are derived for the average spectral efficiency (ASE) and bit error outage (BEO). In addition, for MAM with joint power control, optimal power adaptation strategy and switching thresholds are obtained. Compared with the conventional fast adaptive modulation, which requires fast-varying small-scale fading information, the proposed MAM scheme achieves similar ASE performance with slight increase in BEO.