Information Rate Performance of Massive MU-MIMO Uplink with Constant Envelope Pilot-based Frequency Synchronization

TL;DR

This paper introduces a constant envelope pilot-based frequency synchronization method for massive MU-MIMO uplink, demonstrating improved MSE performance and energy-spectral efficiency over existing techniques, with an achievable array gain.

Contribution

It proposes a low-complexity CE pilot-based CFO estimator that outperforms high-PAPR pilot methods in MSE and efficiency, enabling an () array gain in massive MIMO.

Findings

Better MSE performance than existing methods

More energy- and spectrally-efficient in imperfect CSI scenarios

Achieves () array gain

Abstract

In this paper, we consider a constant envelope (CE) pilot-based low-complexity technique for frequency synchronization in multi-user massive MIMO systems. Study of the complexity-performance trade-off shows that this CE-pilot-based technique provides better MSE performance when compared to existing low-complexity high-PAPR pilot-based CFO (carrier frequency offset) estimator. Numerical study of the information rate performance of the TR-MRC receiver in imperfect CSI scenario with this CE-pilot based CFO estimator shows that it is more energy-and-spectrally efficient than existing low-complexity CFO estimator in massive MIMO systems. It is also observed that with this CE-pilot based CFO estimation, an $\mathcal{O}(\sqrt{M})$ array gain is achievable.