Generation and characterization of orthogonal FH sequences for the cognitive network

Abstract

The existing orthogonal frequency hopping (FH) sequence cannot support the high throughput and high spectrum efficient cognitive FH (CFH) network due to its small family size, high computational complexity and short period. To overcome these disadvantages, this paper investigates the generation of the orthogonal FH sequence and analyzes its multiple accessibility performance based on the CFH frequency division multiple-access (FDMA) network model. By the random mapping and cyclical shift replacement (CSR) scheme, a large family size of orthogonal FH sequence with dynamic frequency slot number is generated. In this case, the external interference could be eliminated by avoiding the interfered frequencies, and blocking mutual interference incurred for the packet by the orthogonal frequencies. Moreover, the theoretical relationships of the throughput and transmission delay with respect to the user number and the packet arrival rate are given, which shows that our proposed orthogonal FH sequence could support high throughput and short packet transmission delay in CFH-FDMA network. The simulation results validate our theoretical analysis of the CFH-FDMA network performance, and show that our proposed sequence outperforms the widely used no hit zone FH sequences in terms of uniformity, randomness, Hamming correlation, complexity and sensitivity, etc.

摘要

创新点

针对认知跳频系统高吞吐量、高频谱效率正交组网迫切需求, 本文提出了一种正交跳频序列族的生成方法。 该方法能够生成大量依据系统感知结果实时改变的跳频序列, 实现大量用户动态接入。 基于该序列, 对正交频分多址接入系统进行分析, 得到了系统吞吐量和传输时延与通信用户数之间的理论表达式, 为实际认知跳频系统的正交组网提供了理论依据和技术支持。