Design And Implementation Of Single Carrier Frequency Domain Equalization Based On FPGA

Shortwave communication is a common way of wireless communication, it is extensively applied in military and meteorological communication. But there are serious multipath effects in the shortwave channel,which may worsen the system performance.Therefore, to improve the transmission performance of the system, the method of anti-multipath fading is particularly important. Single carrier frequency domain equalization(SC-FDE) is a new technology of anti-multipath fading. It is an innovative combination of frequency domain equalization technique and single carrier technology. SC-FDE not only can against multipath fading to allow an advantageous of high-speed data transmission, it can also reduce the complex operation in the single carrier time domain equalization (SC-TDE)systems and the high peak to average power radio in orthogonal frequency division multiplexing (OFDM) systems. In view of this, the thesis takes SC-FDE into shortwave communication as the research topic.Firstly, the thesis describes the definition and characteristics of shortwave communication,and analyzes the characteristics of shortwave channel,including propagation mode, the effect of multipath and Doppler effect. Then introduce the fading and noise in shortwave channel in detail. The thesis introduces two kinds of widely used modeling methods: Watterson model and ITS model, and simulate ten kinds of shortwave channels referring to ITU-R.Then, this article gives the model description and the mathematical description for SC-FDE system. It gives the comparison on peak to average power ratio, channel capacity and BER performance with OFDM. Next, discuss the frame structure of SC-FDE system, and introduce two kinds of unique word that suit to the cyclic prefix of SC-FDE system, they are Frank-Zadoff sequence and Chu sequence. Researches the unique word in amplitude frequency characteristic and self-correlation function and analyzes the impact of different frame structre of the system performance. Then this article introduces the fundamentals of channel estimate and frequency equalization technology, and researches the interpolation algorithm in channel estimate in detail. Compares and analyzes the system performance of ZF equalization and MMSE equalization by means of Matlab.Finally, based on the frontal theoretical research and the simulation of the Matlab,designs FPGA hardware implementation, including signal transporting module and signal receiving module tow parts. Use ISE platform of Xilinx company to profit logic synthesis and functional simulation. Compares the simulation results of FPGA and Matlab, and verifies the correct of hardware programming. At last, use XC6SLX9 development board to on-board debug and verify its correct.