时频无碰撞区和低碰撞区跳频序列设计研究

发布时间：2018-11-20 07:51

【摘要】：跳频(Frequency Hopping,FH)通信是一种以跳频序列为扩频序列的重要的扩频通信技术。跳频码分多址(Frequency Hopping Code Division Multiple Access,FH-CDMA)通信系统抗多址干扰和抗多径干扰的能力取决于跳频序列的汉明相关性。无碰撞区(No Hit Zone,NHZ)和低碰撞区(Low Hit Zone,LHZ)跳频序列在一定的相关区范围内具有极佳的汉明相关特性。根据这一特点,基于NHZ/LHZ跳频序列的准同步FH-CDMA系统,可以消除或降低干扰。本文主要研究了时频无碰撞区跳频序列的构造方法、时频低碰撞区跳频序列理论界、时频低碰撞区跳频序列集的构造及其性能分析。首先,将已有的一维跳频序列无碰撞区扩展到时频二维,介绍了时频无碰撞区跳频序列集的理论界,并给出了两种构造方法。其次,将已有的一维跳频序列低碰撞区扩展到时频二维,提出了时频低碰撞区跳频序列的基本概念,运用数学证明,建立了时频低碰撞区跳频序列集最大周期汉明相关理论界、时频低碰撞区跳频序列集最大周期部分汉明相关理论界及时频低碰撞区跳频序列集平均周期部分汉明相关理论界。最后,基于Welch Costas序列和Golomb Costas序列,通过循环移位的方法构造了一类时频低碰撞区跳频序列集。序列集满足跳频序列的二维周期汉明自相关函数和互相关函数构成的理论界,同时在时频低碰撞区内能获得极佳的自相关特性和理想的互相关特性。
[Abstract]:Frequency hopping (Frequency Hopping,FH) communication is an important spread spectrum communication technology with frequency hopping sequence as the spread spectrum sequence. The ability of frequency hopping code division multiple access (Frequency Hopping Code Division Multiple Access,FH-CDMA) communication system to resist multiple access interference and multipath interference depends on the hamming correlation of frequency hopping sequences. The frequency hopping sequences in collision free region (No Hit Zone,NHZ) and low impact area (Low Hit Zone,LHZ) have excellent hamming correlation characteristics in a certain range of correlation regions. According to this characteristic, quasi synchronous FH-CDMA system based on NHZ/LHZ frequency hopping sequence can eliminate or reduce interference. This paper mainly studies the construction method of time-frequency collision-free region frequency hopping sequence, the theoretical bound of time-frequency low collision zone frequency hopping sequence, the construction and performance analysis of time-frequency low collision region frequency hopping sequence set. Firstly, by extending the existing one-dimensional frequency hopping sequences into two dimensions, the theoretical bounds of time-frequency collision-free frequency hopping sequences are introduced, and two construction methods are given. Secondly, the basic concept of time-frequency low impact region frequency hopping sequence is put forward by extending the existing one-dimensional frequency hopping sequence with low collision zone. The maximum periodic hamming correlation theory bound of time-frequency low impact region frequency hopping sequence set is established by mathematical proof. Theory bound of maximum period partial hamming correlation of frequency hopping sequence sets in time-frequency low impact zone. Finally, based on Welch Costas sequence and Golomb Costas sequence, a class of frequency-hopping sequences in time-frequency low collision region is constructed by cyclic shift method. The sequence sets satisfy the theoretical bound of two-dimensional periodic hamming autocorrelation function and cross-correlation function of frequency hopping sequence. At the same time, the best autocorrelation property and ideal cross-correlation characteristic can be obtained in time-frequency low collision region.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN914.41

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