Development of cooperative relay using universal software radio peripheral

Abstract

To meet the demand for high speed data, wireless cellular system technology has grown in a steady pace. However, the wireless signals are still vulnerable to the multipath fading, shadowing and path loss, making the communication less reliable. Cooperative relay is a techniques to improve signal reliability by introducing a an additional node between source terminal and destination terminal to provide redundant path for data transmission. However, existing work of cooperative relay investigate performance through theoretically simulation only. The real world performance remains unknown because the lack of prototype for field testing and measurement. The focus of this work is therefore to implement the cooperative relay prototype using Universal Software Radio Peripheral (USRP) and LabVIEW platform. The relay prototype based on Amplify-and-Forward (AF) protocol has been developed. The performance in terms of bit error rate (BER) of the cooperative relay link is compared with the direct link without relay. The measurement is carried out in the indoor environment. Measurement results show that the cooperative relay significantly improves the signal reliability and extends the coverage distance if compared to direct communication without relay.