Research On Key Technologies Of Multi-Carrier Wireless Communication System

In recent decades,wireless communications has developed rapidly.People are enjoying the convenience of wireless communication at the same time,the communication speed requirements are getting higher and higher.However,multi-path effect,frequency selective fading and serious lack of spectrum resources has become a bottleneck to curb the cause of wireless communications.Orthogonal frequency division multiplexing(OFDM)can decompose the wideband channel into several sub-narrowband channels,transform the frequency-selective fading of the broadband into flat fading in the narrowband,which makes the OFDM technology have high spectral efficiency and high anti-multipath Extension and many other advantages.This paper introduces the basic principle and system architecture of OFDM system firstly,and expounds the key technology in OFDM system.Based on MATLAB,the OFDM system is simulated and analyzed.The key techniques,peak-to-average ratio and channel estimation are introduced and simulated.Methods for reducing the peak-to-average ratio are the limiting method,selective mapping(SLM)and partial sequence transfer(PTS).The channel estimation method has the least square error method(LS)and the minimum mean square error method(MMSE).Based on the architecture of software radio,the hardware platform of OFDM system is introduced and analyzed.Xilinx Zynq-7000 is selected as the digital signal processing unit,AD9361 of ADI as the radio frequency processing unit of hardware,and gives the hardware platform Design.According to the design,completed based on "Zynq + AD9361" hardware platform.The platform is divided into two parts:baseband board and RF board.Baseband board to Zynq-7000 SOC as the core,including the DDR3 and FLASH storage.The RF board mainly includes AD9361 and Zynq peripheral interface.Finally,this paper implements the OFDM communication system on the hardware platform.