A Soft Spreading Code Optimization Method for Hybrid Spread Spectrum Multiple Access Network

Abstract

The invention provides a soft spreading code optical selection method of a mixed spread spectrum multiple-access network; the method comprises the following steps: setting limit conditions according to structure characteristics of a cyclic shift keying (CCSK) code, and forming a code database satisfying proportionality and autocorrelation requirements; employing an origin traversal-initial random-end segment directed segmented search method to screen a set of soft spreading codes satisfying cross correlation requirements from the autocorrelation code database; finally combining with a frequency hopping pattern so as to reasonably distribute the soft spreading codes to each network for usage. The method can effectively reduce the internetwork interferences, thus improving the system networking ability.

Description

technical field [0001] The invention relates to the field of hybrid spread spectrum time division multiple access communication system, in particular to the optimization and application method of the soft spread spectrum code. Background technique [0002] In the hybrid spread spectrum TDMA communication system, each user of the same network uses TDMA to share the channel, and uses frequency hopping and soft spread spectrum technology in each time slot to make the system have multi-network capability, that is, different network users The transmitted signals are kept orthogonal in the frequency or code domain. Specifically, when the frequency hopping frequency points of signals transmitted by different network users collide randomly, that is, when the signals collide in the frequency domain, using soft spreading codes for spreading can ensure that the signals are orthogonal in the code domain. For example, in the LINK16 data link of the US military, a 32-bit cyclic shift key...

AI Technical Summary

Problems solved by technology

However, the current soft-spreading code screening algorithm does not fully consider the code word structure characteristics of the cyclic code itself when searching, and directly searches the 232 space when generating the autocorrelation code library, which leads to a large amount of calculation and can only be randomly generated. The method of related code library

Moreover, the low-efficiency exhaustive search method is often used in the cross-correlation screening, and the efficiency of generating codewords is low and the number is small, which is difficult to meet the requirements of the multi-network application of the hybrid spread spectrum time division multiple access communication system.

In addition, regarding the multi-network allocation method of soft spreading codes, pseudo-random allocation is often used at present, which cannot ensure the orthogonality of signals in the code domain when frequency point collisions occur.

Images