Constant Envelope Pilot-Based Low-Complexity CFO Estimation in Massive MU-MIMO Systems

TL;DR

This paper introduces a low-complexity CFO estimation algorithm for massive MIMO systems using constant envelope pilots, leveraging spatial averaging to achieve efficiency and power savings as the number of antennas grows.

Contribution

The paper proposes a novel CFO estimation method that is computationally linear in the number of antennas and demonstrates power reduction with increasing antennas.

Findings

Complexity is linear in the number of BS antennas.

Transmit pilot power decreases as 1/√M with more antennas.

Maintains fixed MSE of CFO estimation regardless of M.

Abstract

In this paper we consider a constant envelope pilot signal based carrier frequency offset (CFO) estimation in massive multiple-input multiple-output (MIMO) systems. The proposed algorithm performs spatial averaging on the periodogram of the received pilots across the base station (BS) antennas. Our study reveals that the proposed algorithm has complexity only linear in $M$ (the number of BS antennas). Further our analysis and numerical simulations also reveal that with fixed number of users and a fixed pilot length, the minimum required transmit pilot power decreases as $\frac{1}{\sqrt{M}}$ with increasing $M$, while maintaining a fixed desired mean squared error (MSE) of CFO estimation.