Long and short code estimation method for multi-rate long and short code direct spread code division multiple access signals

Abstract

The invention discloses a long-short code estimation method of a multi-speed long-short code direct sequence-code division multiple access signal. Firstly, according to the largest long scrambling code cycle and the smallest spreading code cycle of a received signal, the received signal is segmented twice to obtain a signal matrix, and according to a Fast-ICA algorithm, complex code fragments of all users are obtained through separation; then, with gradual reducing of information speeds, a user long-short code sequence is estimated, the complex code fragments obtained by separating the Fast-ICA algorithm are spliced to constitute a fuzzy sequence, a secondary delay multiplying method is adopted to remove sequence fuzziness and spreading code interference, and in combination of a cyclotomiccoset and three-order relevant characteristics and according to a characteristic information matching method, long interference code estimation corresponding to all users at the same speed is completed; meanwhile, relevant calculation estimates the short spreading code, and then through a similarity coefficient matrix, all the complex code fragments of the estimated users are removed till long-short code estimation of all the users is completed.

Description

technical field [0001] The invention belongs to the field of parameter estimation of direct spread signals in communication, in particular to a method for estimating length codes of multi-rate long and short code direct spread code division multiple access signals using short code spreading and long code scrambling. Background technique [0002] Direct sequence spread spectrum (DSSS) has the advantages of strong anti-interference ability, good concealment, and easy code division multiple access, etc., and has been widely used in military and civilian fields. [0003] With the continuous development of spread spectrum communication, the traditional DSSS technology has limited its application in high-speed data transmission due to the contradiction between processing gain and data rate. In order to provide better services and applications, multi-rate direct sequence spread spectrum technology is introduced in spread spectrum communication. The direct spread code division mult...

AI Technical Summary

Problems solved by technology

These methods have certain effects for simple direct spread signals, but cannot be directly used for multi-rate LSC-DS-CDMA signals

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