Performance Analysis of SDR based Wireless Relay Networks

In this paper, we have studied the Software Defined Radio (SDR) based wireless relay network. The relay employs the SDR architecture to implement the cross functionality of relaying techniques depending upon the network requirements. The cross functionality between two main relaying techniques Amplify-and-Forward (AF) and Decode-and-Forward (DF) is studied. The proposed SDR approach combines the gain of DF relaying at low SNR and AF relaying at high SNR region. We analyse the system performance in terms of parameters mainly outage probability, erogodic capacity and throughput under rayleigh fading channels. Based on the Channel state information (CSI), we use Bit Error Rate (BER) constraint along with the adaptive modulation to set the threshold limits. Using monte carlo simulations we show that the capacity gain of about 12% is achieved using SDR based relay than using individual techniques for a given BER constraints of the wireless link.