THROUGHPUT EVALUATION OF IoT LOW-POWER WIDE-AREA SYSTEM

Abstract

This article suggests integrating two intelligent reflecting surfaces (IRS) with a relay to improve the system throughput of an Internet of Things (IoT) applied in a low-power wide-area network (LPWAN). In particular, the proposal incorporates two IRSs to enhance links between the IoT sensor and the relay, as well as between the relay and the IoT gateway. Analytical expression for system throughput is derived for the IRS-relay assisted LPWAN operating over Nakagami-m channels. Then, the throughput of the proposed LPWAN is compared with that of traditional LPWAN without IRS to clarify the significant performance enhancement achieved by leveraging IRS. Specifically, with a certain throughput, the proposed LPWAN can reduce power consumption 10 dBm compared to the traditional LPWAN. The findings have indicated that the IRS-relay assisted LPWAN can effectively operate at high-frequency bands (5 GHz) for long-range transmission (200 m). Additionally, the article studies and explores detailly the impact of factors such as the data transmission rate, IRS locations, number of reflecting elements, carrier frequency, and bandwidth on the system throughput. Then, some useful recommendations to enhance the system throughput are proposed.