Performance Analysis of Asynchronous Multicarrier Wireless Networks

TL;DR

This paper introduces a new analytical framework for asynchronous multicarrier wireless networks, quantifying the impact of timing misalignments on system performance and evaluating mitigation strategies.

Contribution

It develops a tractable SINR model for asynchronous OFDM networks and analyzes key performance metrics, addressing the effects of asynchrony in various wireless systems.

Findings

Loss of orthogonality due to asynchrony reduces system throughput.

The proposed model accurately predicts the number of decodable transmitters.

Mitigation strategies improve system performance under asynchronous conditions.

Abstract

This paper develops a novel analytical framework for asynchronous wireless networks deploying multicarrier transmission. Nodes in the network have different notions of timing, so from the viewpoint of a typical receiver, the received signals from different transmitters are asynchronous, leading to a loss of orthogonality between subcarriers. We first develop a detailed link-level analysis based on OFDM, based on which we propose a tractable system-level signal-to-interference-plus-noise ratio (SINR) model for asynchronous OFDM networks. The proposed model is used to analytically characterize several important statistics in asynchronous networks with spatially distributed transmitters, including (i) the number of decodable transmitters, (ii) the decoding probability of the nearest transmitter, and (iii) the system throughput. The system-level loss from lack of synchronization is quantified, and to mitigate the loss, we compare and discuss four possible solutions including extended cyclic prefix, advanced receiver timing, dynamic receiver timing positioning, and semi-static receiver timing positioning with multiple timing hypotheses. The model and results are general, and apply to ad hoc networks, cellular systems, and neighbor discovery in device-to-device (D2D) networks.