Research On OFDM System Based On GNURadio And USRP

In the last thirty years, wireless mobile communications have gone through rapid development. Software radio was brought out in1992for military communications, and it was developed into practical platform from theory. Currently, the most widely used software radio platform is a combination of GNURadio and USRP.Orthogonal frequency division multiplexing (OFDM) is a special multi-carrier modulation. The advantage of OFDM is mitigation intersymbol interference and high spectral efficiency. The disadvantage is its sensitivity to the timing and frequency offset, the peak are relatively huge. OFDM is already the core technology in4G standard and it’s application in mobile communication system is imperative.This paper used GNURadio and USRP platform to do research on OFDM system By analyzing the basic principles of software radio platform’s structure and OFDM, OFDM transceiver system on GNURadio and USRP platform is realized, and the actual measurement results were analyzed. Channel coding module is added to improve the reliability of the system while measuring packets’transmitting and receiving. Energy detection algorithm is realized in this platform to measure the spectrum occupancy.In the end, m-sequence correlation method is used to measure the channel response indoor by sending and receiving signals and make a correlation operation.