Single-Carrier Modulation for Large-Scale Antenna Systems

TL;DR

This paper explores the use of single-carrier modulation in large-scale antenna systems for uplink transmission, proposing a waveform recovery method that addresses practical limitations like finite antennas and correlated channels.

Contribution

It introduces a novel waveform recovery theory for single-carrier modulation in large-scale antenna systems, moving beyond the traditional OFDM approach and analyzing real-world constraints.

Findings

Waveform recovery enables direct sampling of transmitted signals.

Analysis of finite antennas and correlated channels impacts.

Potential improvements over OFDM in uplink scenarios.

Abstract

Large-scale antenna (LSA) has gained a lot of attention due to its great potential to significantly improve system throughput. In most existing works on LSA systems, orthogonal frequency division multiplexing (OFDM) is presumed to deal with frequency selectivity of wireless channels. Although LSA-OFDM is a natural evolution from multiple-input multiple-output OFDM (MIMO-OFDM), the drawbacks of LSA-OFDM are inevitable, especially when used for the uplink. In this paper, we investigate single-carrier (SC) modulation for the uplink transmission in LSA systems based on a novel waveform recovery theory, where the receiver is designed to recover the transmit waveform while the information-bearing symbols can be recovered by directly sampling the recovered waveform. The waveform recovery adopts the assumption that the antenna number is infinite and the channels at different antennas are independent. In practical environments, however, the antenna number is always finite and the channels at different antennas are also correlated when placing hundreds of antennas in a small area. Therefore, we will also analyze the impacts of such non-ideal environments.