User Grouping for Non-Coherent DPSK Massive SIMO with Heterogeneous Propagation Conditions

Most designs for multi-user non-coherent massive single input multiple output (m-SIMO) uplink system based on M-DPSK are proposed for Rayleigh fading. The inter user interference complicates their usage in Rician channels. For this reason the designs had to be only considered for two users due to the high complexity at the receiver side. In the context of 5G, the scenarios may be subject to heterogeneous fading conditions. Therefore, in this paper we analyze a multi-user non-coherent m-SIMO in heterogeneous propagation conditions for contemplating more realistic scenarios, where both Rayleigh and Rician fading may be present. The performance analysis shows that the adequate user grouping with different fading in the same physical resource allows unifying the constellation for both groups of users and the detection algorithm, reducing the complexity of the receiver. Also, the number of users that may be multiplexed may be further increased thanks to the improved performance.