Structured Compressive Sensing Based Spatio-Temporal Joint Channel Estimation for FDD Massive MIMO

TL;DR

This paper introduces a structured compressive sensing approach for joint spatio-temporal channel estimation in FDD massive MIMO, significantly reducing pilot overhead while maintaining high accuracy.

Contribution

It proposes a novel SCS-based joint estimation scheme with adaptive pilots and an ASSP algorithm, leveraging channel sparsity and correlation for improved performance.

Findings

Accurately estimates channels with reduced pilot overhead.

Approaches the performance of oracle least squares estimator.

Effective in multi-cell scenarios.

Abstract

Massive MIMO is a promising technique for future 5G communications due to its high spectrum and energy efficiency. To realize its potential performance gain, accurate channel estimation is essential. However, due to massive number of antennas at the base station (BS), the pilot overhead required by conventional channel estimation schemes will be unaffordable, especially for frequency division duplex (FDD) massive MIMO. To overcome this problem, we propose a structured compressive sensing (SCS)-based spatio-temporal joint channel estimation scheme to reduce the required pilot overhead, whereby the spatio-temporal common sparsity of delay-domain MIMO channels is leveraged. Particularly, we first propose the non-orthogonal pilots at the BS under the framework of CS theory to reduce the required pilot overhead. Then, an adaptive structured subspace pursuit (ASSP) algorithm at the user is proposed to jointly estimate channels associated with multiple OFDM symbols from the limited number of pilots, whereby the spatio-temporal common sparsity of MIMO channels is exploited to improve the channel estimation accuracy. Moreover, by exploiting the temporal channel correlation, we propose a space-time adaptive pilot scheme to further reduce the pilot overhead. Additionally, we discuss the proposed channel estimation scheme in multi-cell scenario. Simulation results demonstrate that the proposed scheme can accurately estimate channels with the reduced pilot overhead, and it is capable of approaching the optimal oracle least squares estimator.