A wideband ds/fh signal parameter estimation method and system based on keystone transform

Abstract

The invention discloses a broadband DS / FH (Direct Spreading) / FH (Frequency Hopping) signal parameter estimation method and system based on Keystone transform, and aims to provide a high-precision andlow-complexity broadband DS / FH signal parameter fast estimation method. The technical scheme is as follows: using a differential correlation-based DS / FH signal estimation method to obtain a delay time estimation value of a received signal, dispreading the received signal to obtain a dispreading signal by referring to the delay time estimation value; judging the frequency hopping and a symbol turnover position of the received signal according to the delay time estimation value, performing segmented processing on the dispreading signal, and forming a segmented signal matrix by segmented signals; respectively performing Keystone transform on each row of the segmented signal matrix, and respectively carrying out Fourier transform on each row of the signal matrix after the Keystone transform to obtain a frequency domain matrix, taking module square for the frequency domain, and performing non-coherent accumulation according to columns to obtain accumulated vectors; and finding the frequency fm corresponding to a maximum value from the accumulated vectors, and carrying out speed estimation and completing parameter estimation.

Description

technical field [0001] The invention relates to the technical field of spread spectrum communication, in particular to a Keystone transform-based wideband DS / FH signal parameter estimation method and system. Background technique [0002] Broadband direct hop spread (DS / FH) signal has good anti-jamming and anti-interception characteristics, and is widely used in aerospace measurement and control communication and mobile communication and other fields. The synchronization process of the DS / FH signal includes two steps of signal acquisition and tracking, in which the acquisition needs to estimate the relative speed and delay time of the two parties: the relative speed of the two parties can be calculated by the Doppler frequency of the received signal; the delay The time can be calculated by estimating the delay of the frequency hopping pattern and the phase of the direct spread code. In a low signal-to-noise ratio environment, the signal energy within one hop is not enough to...

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Problems solved by technology

Among them, the method based on time-frequency analysis describes the signal as a two-dimensional function of time and frequency, which can accurately reflect the relationship between signal frequency and time variation, but the frequency resolution of this method is low; the method based on sparse linear regression The estimation problem is transformed into a sparse solution problem, which can solve the problem of simultaneous capture of multiple signals, but the method is complicated, the convergence speed is slow, and the signal-to-noise ratio adaptability is poor; the method based on particle filter has high estimation accuracy, but requires sufficient observation Therefore, the real-time performance is poor; based on the method of maximum likelihood estimation, all the parameters to be estimated of the signal are traversed and searched. The principle of the method is simple and the application range is wide, but there is still a problem of large amount of calculation.

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