This paper considers intelligent reflecting surface (IRS)-assisted wireless communication systems having an arbitrary number of reflecting elements in additive white generalized Gaussian noise and general fading channels. It presents unified expressions for the precise bit error rate (BER) analysis of different modulation schemes, including M-ary pulse amplitude modulation (MPAM), M-ary quadrature amplitude modulation (MQAM), and M-ary phase shift keying modulation (MPSK). By applying the unified expressions, we analyze the BER performance in different IRS transmission schemes: intelligent transmission, where the phases of the fading channels are known at the IRS; transmission with imperfect phase shifts, where the phases are partially known and/or the IRS is able to apply discrete phase shifts; and blind transmission, where the phases are unknown at the IRS. The preciseness of the expressions is then verified by Monte-Carlo simulations. Although an IRS with blind transmission achieves a higher BER, it can be a promising candidate for low-cost and low-data rate communications through an ambient IRS that does not require implementation complexity and channel estimation overhead.
- Arbitrary number of reflecting elements
- Bit error rate
- General fading channels
- Generalized Gaussian noise
- Intelligent reflecting surfaces