Multichannel data acquisition method based on static periodic sequence modulation

Abstract

The invention discloses a multichannel data acquisition method based on static periodic sequence modulation. The multichannel data acquisition method is used for parallel low-speed acquisition of high-speed signals. The multichannel data acquisition method comprises the following specific steps that input signals are obtained from a signal receiving and channel preprocessing device; the input signals are pre-modulated through a modulation sequence, so that the pre-modulated signals in different channels are generated; lowpass filtering is conducted on the pre-modulated signal of each channel, so that lowpass signals are obtained; an analog-digital converter is applied to the lowpass signal of each channel, the lowpass signals of the channels are sampled in parallel, and therefore a base band sampled signal of each channel is obtained; a reestablishment matrix is worked out, the base band sampled signals of all the channels form a base band sampled signal matrix, reestablishment is conducted on the base band sampled signal matrix through the reestablishment matrix, and therefore a base band digital signal of each frequency band of the input signals is obtained; the base band digital signals are modulated and combined, and therefore digital sampled signals of the input signals are obtained.

Description

technical field [0001] The invention relates to the technical field of digital signal acquisition and processing, in particular to a multi-channel data acquisition method based on static periodic sequence modulation. Background technique [0002] Digital communication systems need to digitize analog signals and then use digital devices for processing. With the development of modern communication technology, the signal frequency and bandwidth are getting higher and higher, which has gradually approached the highest sampling rate that can be achieved by a single analog-to-digital converter (ADC). If you want to directly sample the broadband signal, the ADC is required to have a very high sampling rate. However, the increase in the ADC rate will lead to a decrease in its quantization accuracy, resulting in a decrease in the dynamic range; and the stability of the sampling clock will also increase with the sampling rate. This will increase the aperture jitter, thereby reducing ...

AI Technical Summary

Problems solved by technology

There are three main types of current multi-channel parallel sampling systems, one is to use analog filters to divide the receiving broadband into several sub-bands, and then use frequency conversion technology to change each sub-band to the base frequency, and finally adopt multi-channel ADC sampling. Filters and frequency converters are complex in design, difficult to implement and difficult to control errors; another method uses multiple low-speed ADCs with mutually prime sampling rates to sample the signals separately, and finally restores the signal with a complete bandwidth through the difference. The sampling rate of each channel is required to strictly satisfy the coprime property, which will bring great difficulties to its realization; the third method adopts the idea of ​​multi-channel delay sampling, and each channel delays the signal differently, and then uses ADC Sampling is combined into the original signal. This method requires a very accurate delay of the signal, otherwise it will cause signal distortion. For high-frequency signals, such precise delay is very difficult to achieve

[0004] It can be seen that the problem existing in the prior art is: how to achieve broadband multi-channel data acquisition in a low-complexity, low-cost, stable and easy-to-implement manner

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