Therefore , fast and reliable synchronization algorithm is one of key technologies in sess system 因此,迅速、可靠地建立同步是自编码扩频通信最主要的环节之一。
Finally , we summarizes the work that had been done and point out some directions need to study in the future 最后对本文工作进行了总结,展望了对自编码扩频通信技术的进一步研究。
In sess , the special way producing the spreading codes determines that the spreading codes are more important in sess communication system 在自编码扩频通信中,特殊的扩频序列产生方式决定了自编码扩频序列对于整个系统性能的影响更是巨大的。
We build the baseband model of the ar self - encoded spread spectrum system both for a user and multi - user , and do a lot of simulation for the system . in addition , we discuss the performance deeply based on the simulation 本文建立了单用户及多用户的ar自编码扩频系统的基带模型,并在仿真结果的基础上,对该系统的性能进行了更深入的讨论。
Some novel technologies are also proposed , such as two dimensional spread spectrum ( 2d - ss ) , self - encoded spread spectrum ( sess ) , multiple input multiple output ( mimo ) , orthogonal frequency division multiplexing ( ofdm ) and so on 另外,对目前新兴的一些抗干扰技术,如二维扩频、超宽带、多天线、自编码扩频等技术也做了简单分析。
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。
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。
The spreading code is acquired from the transmission data source . as a result , the method to generate the spread codes is very important . and the method determines the practical application of sess communication system 自编码扩频通信的扩频序列是从待传输的信源数据流中获得的,因此信源的随机化技术是自编码扩频通信的基础,它在很大程度上决定了自编码扩频通信是否能获得实际应用。
In this article , we introduce the basic principle of the self - encoded direct spread ( seds ) system , construct the model of the system , and analyze the main performances of the system , such as ber performance , self - interference , mai performance and so on 本文介绍了自编码扩频系统的基本原理,构建了系统模型,并对其主要性能,如误码率性能、自干扰特性、多址能力和抗多径干扰能力等作了分析。
At 1999 , lim nguyen first brought forward a novel self - encoded spread spectrum ( sess ) system , which spread spectrum sequence is full builded by the source data . in sess system , which does not use pn codes . it employs random spreading sequences that are extracted from the information data 自编码直扩通信是limnguyen在1999年首次提出的一种利用信源数据产生扩频序列的随机直扩技术,它产生具有随机的、动态可变的扩频序列,因而是一种较好的安全通信方式。