Performance Analysis of IRS-assisted Backscatter Communications Under Hardware Imperfections

In this paper, we consider an intelligent reflecting surface (IRS)-assisted backscatter communication system, where the direct link between the reader (R) and tag (T) is assumed to be unavailable. Taking into account the IRS phase shift dependent (PSD) amplitude response and hardware imperfections (HWI), accurate expressions for outage probability, average symbol error rate, and ergodic capacity are derived. The expressions are then validated through numerical and simulation results. The results reveal that non-ideal IRS PSD amplitude response and HWI severely impact the system performance. It is also shown that HWI introduce a capacity ceiling in the high-power and large number of IRS reflecting elements regimes, which is independent of fading levels and IRS PSD amplitude response.