LAUSR

In this letter, the joint design of user association (UA) and passive beamforming (PBF) has been investigated for heterogeneous networks equipped with reconfigurable intelligent surfaces. Firstly, a closed-form lower bound of ergodic rate is derived using statistical channel state information and adopting the maximum ratio transmission precoding. After that, a joint UA and PBF problem is formulated to maximize the weighted sum-rate (WSR), which is then decomposed into UA and PBF subproblems and solved by our proposed priority-based swapping and fixed-point iteration algorithms. Simulation results demonstrate that our proposed scheme achieves significant WSR performance gain when compared to the state-of-the-art methods.