Research On Direct Sequence Spread Spectrum Receiver Based On Software Radio

As the popularization of radio communication, the emergence of the multi-criterion and multi-mode in the radio communication, the increasing need for co-operation and the lack of radio spectrum resource, traditional radio communication can not satisfy the need of development and facing innovation and breakthrough. How to use the spectrum effectively and how to adapt to all kinds of application environment becomes a hot topic. The software radio technology put forward a feasible way to solve it, its low cost and multi-function becomes a focus. It also changes the method of designing. Direct sequence spread spectrum is a key technology in the intending communication system. It can increase the efficiency of the spectrum bandwidth utilization. This dissertation mainly studies the application of the software radio technology in the direct sequence spread spectrum (DSSS) receiver.Firstly, the concept of the software radio (SDR) and its characteristic are introduced, and the way to realize it is analyzed. And then focus on some stick point of the technology about SDR. Three kinds of structure of SDR were discussed here. Considered the condition in our laboratory, we choose the mid-frequency structure as the topic in this thesis.Secondly, we introduce the concept of DSSS and specify its advantages, headspring and feature. The mathematic expression of DSSS receiver and the characteristic of the PN code are discussed. The spread spectrum communication has advantages of anti-noise, anti-interaction and nice secrecy for the noise characteristic of PN sequence. The ways based on co-correlation to detection are analyzed. Digital matched filter (DMF)...