Abstract

In this paper, the idea of “deep upgrade” of the Cyclic Code Shift Keying (CCSK) is further developed. It is proposed a new method of information transmission for M-ary spread spectrum communication systems, which is orthogonal negacyclic shift keying (ONCSK) based on odd-periodic complementary sequences. The method combines the noise immunity of orthogonal signal systems, the simplicity of signal processing of CCSK and the computational efficiency of FFT, as well as high structural security. The developed digital reception processing algorithm is based on computation of odd correlation functions and application of odd discrete Fourier transform. The scalability of the length of the base code N makes it possible to implement a CDMA system that is adaptive in terms of the frequency band used, the spreading factor, and the data transmission rate.

ONCSK noise immunity gain in compare to CCSK is valuable for applications such as satellite and deep space communication systems, transform domain communication systems, and IoT. In channels with forward error correction (FEC) coding, ONCSK scheme performs better than CCSK with a much larger spreading factor and many times more computationally complex FEC codec. Refined sizes of ensembles of complementary sequences for different lengths N are determined and structural security characteristics of bipolar spread spectrum signals based on them are studied, including aspects, which are specific to ONCSK.

中文翻译：

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基于奇离散傅里叶变换的多进制正交负循环码移键控信号的接收

摘要

本文进一步发展了循环码移键控（CCSK）的“深度升级”思想。提出了一种多进制扩频通信系统信息传输的新方法，即基于奇数周期互补序列的正交负循环移位键控(ONCSK)。该方法结合了正交信号系统的抗噪性、CCSK信号处理的简单性和FFT的计算效率以及较高的结构安全性。所开发的数字接收处理算法基于奇相关函数的计算和奇离散傅立叶变换的应用。基码长度N的可扩展性使得实现在所使用的频带、扩频因子和数据传输速率方面自适应的CDMA系统成为可能。

与 CCSK 相比，ONCSK 的抗噪增益对于卫星和深空通信系统、变换域通信系统和物联网等应用很有价值。在具有前向纠错 (FEC) 编码的信道中，ONCSK 方案的性能优于 CCSK，具有更大的扩频因子和计算复杂度高出许多倍的 FEC 编解码器。确定了不同长度N的互补序列系综的细化大小，并研究了基于它们的双极性扩频信号的结构安全特性，包括ONCSK特有的方面。