Abstract:
The Cooperative transmission is technique that allows multiple nodes to simultaneously transmit data, and these nodes can be used as relays to forward information to the destination. Virtual antenna arrays concluded it is an attractive option to overcome the drawbacks of traditional relaying systems. The examined network consisting of one source, one destination and one relay and considered scenario in it which destination or relay can have various processing limitations. Performance of Relay channel analyzed under principle of amplify-and-forward (AF), decode-and-forward (DF) by comparing between them in the bit error rate (BER) and signals to noise ratio (SNR).Simulation results of comparison between amplify-and-forward, decode-and-forward and direct transmission found that in direct transmission BER is very high as it expected, and the AF is better than DF in BER. Also in amplify-and-forward found that the BER decrease when doubling the amplification factor value, and when using different modulation techniques found that in BPSK and QPSK the BER inversely proportional to SNR and in16QAM it is directly proportional when increase the values of SNR .The simulation done by using MATLAB programming language
