Applied Research On Wideband HF Spread Spectrum System For Data Transmission

The research of this thesis is derived from a project named as"The Research of Wideband HF Spread Spectrum Technology". The objective of this project is that the wideband HF burst data transmission system are designed and implemented on the hardware platform with making use of spread spectrum method. This thesis lays emphasis upon the research of design and implementation of some parts in this system.Firstly, a HF wideband data transmission scheme based on direct sequence spread spectrum is presented, focusing on analysis of the error control coding, soft spread spectrum, shaping filter, synchronization, RAKE receiver, and other key techniques. With MATLAB simulation tools, the entire system is simulated based on the data transmission scheme. The result of the simulation shows that perfect error performance of the whole system can be obtained at low SNR (Signal to Noise Ratio), and the technical requirements are well satisfied.Secondly,the implementation scheme of this system is designed, which is based on FPGA hardware platform. The system scheme is realized by using the combination of SOPC (System on a Programmable Chip) and FPGA logic modules. The SOPC development based on soft processor is a key work of this thesis, including the realization of error control coding based on SOPC, the interface between SOPC and FPGA logic modules, and the interface with the PC. Finally, these modules are tested on the hardware platform, the test results show that the designed interfaces are correct, and the error control coding function of transmitter and receiver is achieved.