Performance analysis of dual-hop mixed relaying cooperative networks with Nth best-path selection

Cooperative relaying is one of the promising technology which is used to improve coverage and spatial diversity. A new relay strategy, the N^th Best-Relay Selection scheme is proposed to improve the bandwidth penalty and to increase the spatial diversity by using a sub-optimal allocation for the relay relative distance between the source and destination in a multi-hop cooperative systems. A single branch dual-hop network and dual branch dual-hop network with adaptive Decode-and-forward (DF) and Amplify-and-forward (AF) cooperative diversity systems is considered. The proposed N^th Best-Relay selection scheme over single branch dual-hop system is compared with dual branch dual-hop network using the closed-form expression. The BER (Bit error rate) and Outage probability using binary and quadrature phase shift keying modulation schemes (BPSK & QPSK) with adaptive mixed decode-and-forward (DF) and amplify-and-forward (AF) cooperative diversity systems over Rayleigh fading channel were estimated. Results show that in the N^th best relay the diversity order is equal to (M -N +2) where M is the number of relays.