One-Way URLLC with Truncated Channel Inversion Power Control

TL;DR

This paper proposes a truncated channel inversion power control method for one-way URLLC that reduces overhead and enhances reliability by eliminating the need for channel estimation, considering finite blocklength and power constraints.

Contribution

It introduces a novel truncated CIPC scheme for one-way URLLC, deriving outage probability and optimizing power to improve reliability under latency and power constraints.

Findings

Truncated CIPC effectively reduces outage probability in one-way URLLC.

Optimal power setting minimizes transmission outage under finite blocklength.

Tradeoffs among reliability, latency, and resource requirements are characterized.

Abstract

In this work, we consider one-way ultra-reliable and low-latency communication (URLLC), where only the transmission in one direction requires URLLC and the transmission in the opposite direction does not. In order to meet the low-latency requirement of the one-way URLLC, we propose to use a truncated channel inversion power control (CIPC) to eliminate the requirement and the associated overhead of the training-based channel estimation at the receiver, while utilizing the multi-antenna technique at the transmitter to enhance the communication reliability. We first derive the transmission outage probability achieved by the truncated CIPC by considering the impact of a finite blocklength and a maximum transmit power constraint. Then, we determine the optimal constant power of the received signals in the truncated CIPC, which minimizes the transmission outage probability. Our examination shows that the proposed truncated CIPC is an effective means to achieve the one-way URLLC, where the tradeoff among reliability, latency, and required resources (e.g., the required number of transmit antennas, or the required maximum transmit power) is revealed.