Design And Implementation Of Broadband FH/DS Baseband Transmission System

Having a strong ability of anti-interference, spread spectrum technology has found wide applications in the military communication and other special areas. Based on the study of hybrid spread spectrum technology which consists of M-ary direct sequence spread spectrum and frequency hopping, the design and implementation of the key modules of the baseband transmission unit is presented. The main contributions are as follows:1Based on the analysis of broadband hybrid spread spectrum communication techniques, the implementation scheme of the transmission system is given.2Based on the research of RS(Reed-Solomon) code and convolution code encoding/decoding principle, the hybrid spread spectrum communication system coding scheme that RS code is outer code, convolution code is internal code is presented.3The M-ary spread spectrum module, the frequency hopping module and the orthogonal carrier modulation module of the hybrid spread spectrum baseband transmission unit are given. All the designed modules are tested in the FPGA chip EP3C55, and the results show that the designed modules can meet the design requirements.4The hybrid spread spectrum baseband unit, the radio frequency unit in the transmission system and the information source device interface unit are jointly tested, the results show that the hybrid spread spectrum transmission system and receiving system can work properly, and the performance meets the design requirements.