Short-wave Narrow-band Digital Direct Sequence Spread Spectrum Communication System Design And Development,

My research realized Direct Sequence Spread Spectrum in shortwave frequency. Design is based on modularization of PCI bus, narrowbands making up wideband, embodying the idea of Software Radio. Meanwhile, I developed a shortwave narrowband digital direct sequence Spread Spectrum transmitter and receiver system. The paper mainly include the following contents: Chapter 1 begins with the background and requests of the task. Other highlights are the design principle of the whole shortwave narrowband DS-SS system and the theory of spread spectrum modulation and its significance. Chapter 2 introduces the architecture of software radio.Chapter 3 explains the design and development of shortwave narrowband digital DS-SS transmitter system. Firstly, it introduces the theory of whole transmitter system. Then it detailly discusses every part's theory and design methods, comprising signal model, spread-spectrum implementing, digital upconverion, pulse shaping, PCI bus, digital design technique etc.Chapter 4 explained the development process of shortwave narrowband digital DS-SS receiver system. It firstly introduces the theory of band sampling and digital down-conversion technology. Then it proposes the despread theory of DS-SS signal and its design plan.Chapter 5 describes the debugging process and testing results of transmitter system. At the end of this paper , I brings forward the needed further work of this task.