Method for rapidly capturing multi-mode high dynamic spread spectrum signal

Abstract

The invention relates to a method for rapidly capturing a multi-mode high dynamic spread spectrum signal which is realized based on an FPGA. The method comprises the steps of: (1) performing double interpolation and down-conversion on an input intermediate frequency sampled data, performing down-conversion on an intermediate frequency digital signal in order to form a zero intermediate frequency and output I and Q two-path zero intermediate frequency signals, (2) generating a zero intermediate frequency signal having a two-times bit rate, (3) inputting the sampled I and Q two-path data to a matched filter, performing relative operation by utilizing a time division multiplex folding algorithm, and outputting the relative operated result of n sections of single points of the I and Q two paths, (4) serially capturing a judged sample value and (5) performing non-coherent accumulation treatment on the serially captured judged sample value according to a pseudo code length in a capturing mode parameter in order to find out a maximum judged sample value and judge whether the value is more than a captured judgment threshold for the purpose of realizing capture judgment. The method can adapt to rapidly capturing a multi-mode high dynamic spread spectrum signal having multi-information rate, multi-pseudo code rate and multi-pseudo code length.

Description

technical field [0001] The invention is the realization of FPGA-based fast capture of signals applied in the field of communication systems, and can satisfy most receiver baseband systems for fast capture of multi-mode high dynamic spread spectrum signals. Background technique [0002] With the diversification of communication system applications, more and more receivers have put forward higher requirements for fast signal acquisition. Almost all receivers require acquisition of IF or baseband signals, and most systems have strict requirements on acquisition time. According to the search and novelty results of relevant literature, there are two main types of fast capture algorithms that are widely used in FPGA and are the most researched: one is the fast capture algorithm based on matched filter, and the other is the fast capture algorithm based on FFT. , both have their own advantages: the former has the advantage of parallel search in the time domain, and the latter has t...

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Problems solved by technology

However, the two algorithms are currently only designed to capture specific signals of a specific system, and have not proposed research on a general algorithm module for multi-mode spread spectrum signals

The current fast capture algorithms generally have two shortcomings: one is that the algorithm optimization and structural optimization are not enough, and its cost performance (the ratio of function, performance and resource consumption cost) is not high enough; the other is that the mode is single and the algorithm flexibility is poor , its algorithm module does not have good versatility, portability and scalability

However, none of the literatures has implemented a universally configurable algorithm module capable of cap

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