Experimental Study Of Wireless Relay Transmission Based On USRP Platform

As one of the research hotspots in the field of communications in recent years, software defined radio(SDR) technology is different from the traditional radio technology. By using software programming to realize most of the signal processing process in traditional radio system, SDR technology can save social resources, greatly shorten the development cycle of the system, and increase the flexibility and versatility of the wireless communication system. Thus,it is thought to be an important developing direction of communication technology in the future. GNU Radio is a completely open software radio project, which has strong ability of reconstruction. As a relatively mature technology, wireless relay technology has the features of providing spatial diversity to overcome multi-path fading, extending region coverage, increasing capacity and low cost.Currently, researches on relay communication are based on theory and then use software emulation to evaluate performance. However, it can not actually simulate communications environment of wireless channel characteristics in reality, so it has a lot of limitations. Introduction of SDR can effectively resolve the low utilization of spectrum resources utilization as well as a waste of hardware resources. Based on the hardware platform Universal Software Radio Peripheral(USRP) and the software platform GNU Radio, this paper will adopt DF(Decode and Forward) relay technology to build a set of wireless multimedia relay communications system and propose a wireless relay implementation scheme on software defined radio. In this paper, different experiments for transferring multimedia files show that system can lower packet loss rate and packet error rate compared by using wireless relay technology, when the channel characteristics of the path to the license is poor. Besides, it can effectively guarantee transmission capacity of system and increase the reliability of communication.