Noncoherent space-time coding for correlated massive MIMO channel with Riemannian distance

This paper considers a massive multiple-input multiple-output (MIMO) uplink system in correlated Rayleigh fading channels. A transmitter with two antennas needs to send data timely to a base station with a large number of antennas. We assume the channel coefficients keep constant during two consecutive time slots and change independently in the following two successive time slots. We construct a Riemannian-distance (RD) based noncoherent detector for such a system. Also, we propose a novel noncoherent parametric space-time coding method. We first attain the closed-form solutions of the optimal sub-constellation structures for fixed modulation orders with the max-min rule. Then, we determine the optimal modulation order for each sub-constellation. The analytical results show that our proposed scheme can attain a larger RD distance than the existing massive uniquely factorable constellation coding (MUFC) scheme. Further, we illustrate that our proposed coding scheme enables a low-complexity RD decoding algorithm. Simulation results show that our proposed scheme performs better than the current phase shift keying modulation scheme and MUFC scheme. (c) 2022 Elsevier Inc. All rights reserved.