The Method Of Blind Detection And Parameter Estimation For DSSS

Because DSSS has many advantages, such as the ability of very strong anti-interference, timing ranging, strong concealment, code division multiple access, anti-multipath interference, etc. Therefore it can be a wide range of applications, especially in the field of military communications. As electronic warfare and information warfare technology, spread spectrum signal detection and parameter estimation under the conditions of non-cooperative communication becomes hot research field of spread spectrum communication. In order to meet the needs of future war against electronic surveillance technology, the study on the method of DSSS signal’s blind detection and parameter estimation in the condition of low SNR has important practical significance.The main work is DSSS signal’s blind detection and parameter estimation in the case of not having any prior knowledge; the paper’s main tasks are as follows:This paper briefly describes the principles and characteristics of spread spectrum technology, and then makes a mathematical analysis of the basic theory. This paper mainly studies secondary spectrum detection, squared frequency detection, cumulant detection, carrying out a detailed theoretical analysis and simulation. Among them, using time domain correlation characteristics of DSSS signal, the secondary spectrum detection method can accurately extract the DSSS signal PN code cycle; Squared frequency detection technology combined with the relevant accumulation can be more precise in the estimation of the carrier frequency of DSSS signal; higher-order accumulation is another way of DSSS signal detection, and the method based on fourth-order cumulant2D slice detection can simultaneously estimate the chip rate and carrier frequency.In the cumulant detection of this paper, a model is established that in a finite set containing a DSSS signal and several simple modulated signals, by means of fourth-order cumulant2D slice power spectrum’s detection methods, DSSS signal in Gaussian channel mixed with several simple modulation signal can be effectively identified.