Performance Analysis of Wireless Mesh Backhauling Using Intelligent Reflecting Surfaces

This paper considers the deployment of intelligent reflecting surfaces (IRSs) technology for wireless multi-hop backhauling of multiple basestations (BSs) connected in a mesh topology. The performance of the proposed architecture is evaluated in terms of outage and symbol error probability in Rician fading channels, where closed-form expressions are derived and demonstrated to be accurate for several cases of interest. The analytical results corroborated by simulation, show that the IRS-mesh backhauling architecture has several desired features that can be exploited to overcome some of the backhauling challenges, particularly the severe attenuation at high frequencies. For example, using IRS with four elements, N=4, provides a symbol error rate of about 10-5 at a signal-to-noise ratio of about 0 dB, even for a large number of hops. Moreover, the obtained analytical results corroborated by Monte Carlo simulation show that the gain obtained by increasing N decreases significantly for N>5. For example, increasing N from 1 to 2 provides about 8 d B of gain, while the increase from 3 to 4 provides about 48 d B. Moreover, the degradation caused by the relaying process becomes negligible when the number of IRS elements N= 3.