Performance and Complexity Tradeoffs of Several Constellations for Non Coherent Massive MIMO

The need to estimate a large number of channels in massive MIMO (mMIMO) has led to the proposal of non coherent (NC) detection, where the channel state information (CSI) is not necessary. In this paper, we discuss the tradeoff between NC designs based on phase-detection (PD) and those based on energy-detection (ED) for mMIMO in terms of performance and complexity. Similarly, we analyze NC schemes with respect to their coherent counterpart. In general, the results show that the PD ones are the best option regarding performance against the ED. Moreover, we analyze the combination of the two detection schemes as an attractive solution at the performance level facing the schemes based merely on energy or phase, in exchange for incrementing the complexity of the receiver. In addition, we propose new constellation schemes for phase based detection multiuser NC-mMIMO systems which allow to multiplex an increased number of users in an easier way.