Performance Analysis of a Novel Dual-Frequency Multiple Access Relay Transmission Scheme

In this paper we present the performance analysis of a novel channel assignment scheme where two non-cooperative independent users simultaneously communicate with their destination through a single relay by using only two frequency channels. The analytic derivation of the probability of symbol error for two main relay techniques will be provided, namely Amplify-and-Forward (AF) and Decode-and-Forward (DF). As shown by the obtained results, our switched-frequency approach results in a model that can achieve full-diversity by means of maximum-likelihood decoding at the receiver. Our results are especially important in the DF case, since in traditional techniques (such as half-duplex two-time slot approaches) two sources simultaneously transmit on the same channel through the first time slot, which necessitates some sort of superposition coding. However, since in our scheme both users transmit over orthogonal channels, such a coding scheme is not required. In addition, it is shown that the DF approach based on our novel channel assignment scheme outperforms the AF scheme, especially in scenarios where the relay is closer to the receiver.