Research On Spread Spectrum Communications System Based On On-board CWTDM

This thesis researches on a new scheme of satellite communication with anti-jamming ability, which is a system based on onboard FDMA-CWTDM (Continuous Wave Time Division Multiplex) conversion according to the idea of a Chinese patent and spread spectrum technique to constitute a mesh network. This scheme can not only avoid the challenging resulted from the complexity of on-board processing, but also support various services for satellite communications. Moreover, it is also convenient for networking.Researching in depth on the new method of on-board FDMA-CWTDM conversion and spread spectrum technique, and considering possible military demand, the thesis puts forward a practical design scheme applied to the satellite spread spectrum communication, and finish some work about the related details and implementation simulation as follows:1. Based on thorough studying of the Multiphase Array FFT De-multiplex Algorithm, the algorithm is improved by using the Orthogonal Sampling Principle, and further a implementation scheme which can benefit its hardware design is proposed.2. The practical sketch of CWTDM is brought forward in view of real instance. In research on de-multiplexing of CWTDM signals, the trouble resulted from frequency bias is studied in depth, thanking to which a synchronization module for De-CWTDM is advanced.3. Deeply studying the Spread Spectrum Communication Principle, the thesis designs a receiver scheme specially for this communication system.4. With a dynamic system design tool, System View by Elanix, many custom tokens for general and special usage is developed, which would be helpful to the hardware implementation of the research result.