扩频序列

• In the transmiting port , optical encoder turns data bits into spread spectrum sequences , then , optical decoder retverts it to data bits with the theory of correlation decoding in the receiving port
  在发送端光编码器将数据比特转换成扩频序列,在接收端光解码器利用相关解码原理将扩频序列恢复为数据比特。
• The pn sequence used by a ds - ss direct affects the performance of system . the pn sequence selected is crux of the ds - ss system . the discovery of chaotic dynamic system broad the way of study of pn sequence
  而扩频系统所使用的扩频序列的性能直接影响到系统的性能，因此选用的扩频序列成为扩频通信系统的关键所在。
• The computer simulation realized direct sequence spread spectrum system which used chaotic spreading sequences instead of pn codes and proved the applicability of using chaotic sequences as spreading codes
  最后用计算机模拟实现了用混沌扩频序列取代伪随机码的直接序列扩频通信系统，说明了混沌扩频序列可作为扩频码使用。
• However in the practice spread spectrum communication system , the phase of the received signal is likely to be uncertain because of the instability of transmitter and receiver ' s clock , transmission delay and multi - path
  而在实际的扩频系统中，由于收、发机时钟不稳定、电波传输时延、多径效应等原因造成接收信号中扩频序列相位不确定。
• Aiming at that spread sequence isn ’ t strict balanceable in the basic seds system , we set up three improved models , which can make the sequence balanceable . at the same time their ber performances are different
  本文针对基本自编码直扩系统的扩频序列无严格的0 / 1平衡特性,建立了三种都能达到扩频序列平衡、但系统误码性能不同的改进模型。
• First , the thesis introduces the correlation properties of complete complementary codes and compares with other traditional sequences . then the code generation principle is described , together with the software implementation
  论文首先介绍了完全互补码的相关特性及与其它扩频序列的比较，阐述了完全互补码的产生原理，并完成了码字生成软件。
• The data recovery at the receiver requires the spreading codes . in sess system , the receiver doesn ’ t know which spreading code will be used , so first it must de - spread the received signal correctly to regenerate the spreading code
  自编码扩频系统的扩频序列是接收端事先未知的,不能用事先设计的本地扩频序列产生器产生,需要由恢复的数据获得。
• Pn acquisition involves coarsely aligning the local replica generated in the receiver with that of the received signal and pn tracking is to realize the synchronization accurately , so pn acquisition is the emphasis and difficulty of pn synchronization
  序列捕获实现扩频序列的粗同步，序列跟踪实现扩频序列的精确同步，序列捕获是扩频序列同步的重点和难点。
• It not only considers the effect of frequency error and data modulation , but also realizes code synchronization and frame synchronization at the same time . all these research work will give a valuable reference to the design of the new communication systems
  本文对扩频通信系统构成和原理,扩频序列设计与优选,扩频序列同步问题进行了研究,并进行了相应的仿真。