Dsss Receiver Code Acquisition And Tracking Technology

The spread-spectrum communication systems have many merits such as the antijamming and anti-multi-diameter ability, using of the frequency spectrum is high ,the confidentiality is good, multiple access communi- cation and so on, so they are concered by people. So far, The spread- spectrum communication systems not only apply in the military corre- spondence, the space conquest, the satellite reconnaissance, but also penetrate into the satellite communication, the mobile communication system, domains and so on positioning system.The synchronized technology is the extremely key technology in spread-spectrum communication systems,they affect directly the recepti- vity quality of the spread spectrum communication receiver. The synchron- ization divide into two parts: Carrier wave synchronization and PN-code synchronization in the spread spectrum communication. In this paper I discusse long sequence PN-code synchronized question under the low signal-to-noise ratio condition and basing on the intermediate frequency direct sequence spread spectrum receiver design, they includ pseudo-noise code acquisition and pseudo-noise code tracking.At first I take the spread-spectrum communication systems principle as a foundation, introduce simply several ways of the spread- spectrum communication systems as well as their synchronizations, then propose one kind of design of intermediate frequency digitization direct sequence spread spectrum receiver, and introduce in detail to each constituent function and thehardware realization. The pseudo-noise code acquisition and the tracking are realized by core partial digitization processing unit.In pseudo-noise code acquisition,I analyze performance of msequence and each kind of pseudo-noise code acquisition technology specially under low signal-to-noise ratio condition long sequence PN-code fast capture question. And aimed at this characteristic , I point out a fast code-acquistion using FFT and the large step fast acquistion of delay locked loop. In the PN-code tracking , discusse the code tracking techno- logy of delay locked-loop, including working principle , performance and design method. Finally correlation theories are confirmed by the computer simulation...