Short-Packet Communications in Non-Orthogonal Multiple Access Systems

TL;DR

This paper explores the application of non-orthogonal multiple access (NOMA) in short-packet communications to enhance low-latency wireless networks, demonstrating NOMA's superiority over traditional OMA in throughput and latency reduction.

Contribution

It introduces NOMA into short-packet communications, optimizing transmission and power allocation to improve throughput and reduce latency, a novel integration not previously studied.

Findings

NOMA outperforms OMA in effective throughput under the same latency.

NOMA achieves lower latency for the same throughput targets.

Performance gap widens as throughput targets at users become closer.

Abstract

This work introduces, for the first time, non-orthogonal multiple access (NOMA) into short-packet communications to achieve low latency in wireless networks. Specifically, we address the optimization of transmission rates and power allocation to maximize the effective throughput of the user with a higher channel gain while guaranteeing the other user achieving a certain level of effective throughput. To demonstrate the benefits of NOMA, we analyze the performance of orthogonal multiple access (OMA) as a benchmark. Our examination shows that NOMA can significantly outperform OMA by achieving a higher effective throughput with the same latency or incurring a lower latency to achieve the same effective throughput targets. Surprisingly, we find that the performance gap between NOMA and OMA becomes more prominent when the effective throughput targets at the two users become closer to each other. This demonstrates that NOMA can significantly reduce the latency in the context of short-packet communications with practical constraints.