Spread spectrum signal accurate capturing system

Abstract

A spread spectrum signal accurate capturing system disclosed by the invention is good in processing real-time performance, small in frequency measurement error, high in estimation accuracy and low in adaptive signal-to-noise ratio. According to the technical scheme, a sampling cache module carries out downsampling processing on a received signal and controls ping-pong read-write of sampled data; the compensation correction module divides a Doppler frequency shift range into a plurality of frequency sub-slots to perform frequency compensation of carrier Doppler frequency shift and phase correction of pseudo code Doppler frequency shift on sampling data; parallel search of pseudo code phases is realized by adopting a double-block expansion technology and fast Fourier transform; dual measurement of full coherent integration, carrier Doppler frequency shift and change rate of the carrier Doppler frequency shift is realized by adopting a change rate compensation technology and fast Fourier transform; and integral peak value related information is obtained by adopting a comparative search method for all integral processing data, and the accurate pseudo code initial phase, pseudo code Doppler frequency shift, carrier Doppler frequency shift and carrier Doppler change rate of the spread spectrum signal are solved.

Description

technical field [0001] The invention belongs to the field of wireless communication, and relates to a system for accurately capturing spread spectrum signals based on double-block expansion. [0002] technical background [0003] Spread spectrum communication has become the consensus of people because of its strong anti-interference and anti-multipath ability, high spectrum utilization rate, multiple access communication and many other advantages. As a modern communication system based on information theory, spread spectrum technology has many unique advantages because it uses pseudo-random codes to spread spectrum modulation for data information: it is used in communication, has strong anti-interference ability, and low transmission power , high anti-interception ability, good confidentiality performance, and has the characteristics of code division multiple access and arbitrary location; in ranging, using pseudo-random code ranging can greatly improve ranging accuracy. Bec...

AI Technical Summary

Problems solved by technology

The sliding correlation method is simple, easy to implement, and widely used, but it takes a long time and the acquisition speed is slow; the parallel frequency method uses a long-point Fast Fourier Transform (FFT) to complete the search for the carrier frequency at one time, but the acquisition The time is proportional to the length of the pseudo code, and the signal sensitivity is easy to deteriorate, and the hardware resource consumption is large; the parallel code phase method uses FFT to complete the long pseudo code phase search at one time, and the acquisition speed is fast, but the carrier frequency search range is small, and the carrier frequency The measurement error is large; based on the partial matched filter and FFT acquisition method, as a time-frequency two-dimensional parallel search method, it can not only overcome the shortcomings of slow search speed, but also overcome the serious problem of correlation peak attenuation, but it does not measure the number of carriers. Puller rate of change, difficult to adapt to high dynamic scenes

Therefore, the methods and strategies of the traditional spread spectrum signal acquisition system have their own advantages and disadvantages, and can adapt to certain specific application scenarios, but they cannot meet the mutual influence and restriction of the signal-to-noise ratio threshold, high dynamic conditions, acquisition time, hardware resources, etc. Achieving the best performance in contradiction

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