Amplify and forward relaying optimization for uplink CDMA communications subject to constant multiple access interference cost

In radio mobile cellular networks, the users located at the cell border are suffering from a bad quality of service (QoS). Cooperative communications is a promising technique that can overcome this weakness by allowing the users to profit from powerful benefits of the spatial diversity. Nevertheless, abstraction is usually made on the impact of the additional multiple access interference inherent to relaying. In this paper, we propose a novel approach that optimizes the system performance of an amplify-and-forward (AF) relaying scheme subject to a constant multiple access interference cost for the uplink CDMA (Code Division Multiple Access) communications. We present a variety of simulation results illustrating the cellular system performance enhancement in term of BER (Bit Error Rate) over direct transmission.