Aperiodic long-code DSSS signal spread spectrum sequence blind estimation method based on similarity

Abstract

The invention claims an aperiodic long-code DSSS signal spread spectrum sequence blind estimation method based on similarity, which belongs to the technical field of signal processing. Firstly, an information code library within a single spread spectrum period is constructed according to signal characteristics, then information code sequences within the single spread spectrum period are recognized by utilizing similarity, and a group of ''new information codes'' with number equal to that of information codes in a DSSS signal is constructed through sequential circulation. The ''new information codes'' are multiplied by the DSSS signal to form a ''new DSSS signal''. The ''new DSSS signal'' is segmented to construct a matrix according to a spread spectrum period, a self-correlation function of the matrix is solved, the self-correlation function is subjected to characteristic decomposition, and a characteristic vector corresponding to an obtained maximum characteristic value is a spread spectrum sequence estimated value. The aperiodic long-code DSSS signal spread spectrum sequence blind estimation method can estimate the spread spectrum sequence of the aperiodic LC-DSSS signal accurately at a low signal-to-noise ratio, thus provides favorable condition for blind dispreading of the LC-DSSS signal, is easy to operate, and has an important engineering significance.

Description

technical field [0001] The invention relates to direct sequence spread spectrum communication signal processing, in particular to a method for blind estimation of spread spectrum sequence of aperiodic long code direct spread signal based on similarity. Background technique [0002] Direct Sequence Spread Spectrum (DSSS) communication signals use spread spectrum sequence (or PN code) technology to expand the original narrowband digital signal to a very wide spectrum range before transmission, so that the signal spectrum is broadened and the signal is reduced. Power spectral density, can work in the negative signal-to-noise ratio environment, that is, the signal is submerged in the noise, has the advantages of strong anti-interference, anti-multipath, low probability of interception, multiple access multiplexing, etc., and has been obtained in the field of civil and military communications. Wide range of applications. For example, the CDMA system in the current third-generati...

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Problems solved by technology

[0010] The technical problem to be solved by the present invention is to propose a blind estimation of the spread spectrum sequence of the non-periodic long code direct spread signal based on the similarity to the problem that the spread spectrum sequence of the current aperiodic LC-DSSS signal is difficult to estimate under low signal-to-noise ratio method

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