In this paper, our objective is maximizing total sum-rate subject to power constraints on total relay transmit power or individual relay powers, for amplify-and-forward single-antenna relay-based wireless communication networks. We derive a closed-form solution for the total power constraint optimization problem and show that the individual relay power constraints optimization problem is a quad...

An intelligent reflecting surface (IRS) consists of a large number low-cost elements, which can steer the incident signal collaboratively by passive beamforming. This way, IRS reconfigures wireless environment to boost system performance. In this letter, we consider an IRS-assisted uplink non-orthogonal multiple access (NOMA) system. The objective is maximize sum rate all users under individual...