Fairness-based transmission design in intelligent reflecting surface aided multi-user MISO systems

This paper investigates fairness-based transmission design in Intelligent Reflecting Surface (IRS) assisted downlink transmission scheme for multi-user MISO system. IRS is dedicatedly deployed for assisting the wireless transmission and suppressing the interference among users. The minimum weighted signal-to-interference-plus-noise ratio (SINR) of users is maximized by jointly optimizing the precoding matrix and the phase shift matrix of IRS in order to improve fairness among users. We proposed Successive Convex Approximation-Alternating Optimization (SCA-AO) method to solve the non-convex problem, and analyze the effect of weighted factors on performance. Verified by simulation results the approach of SCA-AO performance is better then method of Exact-Alternating-Optimization (EAO).