Method for processing broadband receiving digital front end

Abstract

The invention discloses a method for processing a broadband receiving digital front end, which comprises the following steps that: 1, received radio frequency signals are divided into n paths of signals, and each path of the signals is subjected to frequency mixing respectively, and the difference of the frequencies of the frequency mixing among the paths is 80 MHz, then the paths of signals are processed respectively and are transmitted to an AD (Analogue-Digital Converter) for sampling with the sampling frequency of F1, and digital medium frequency signals with the centre frequency of F2 and the bandwidth of 80MHz are generated by each path, and are transmitted to a FPGA (Field Programmable Gata Array) for processing; 2: a corresponding AD is selected to input signals according to a current signal frequency code of the system, a DDS (Digital Display Scope) is controlled to generate orthogonal digital local oscillation consistent with a signal frequency spectrum sampled by the AD, the signals input by the AD are multiplied by the orthogonal digital local oscillation generated by the DDS respectively and the frequency spectrum is shifted to a zero intermediate frequency to carry out orthogonal decomposition to acquire an I path of baseband signals and a Q path of baseband signals which are orthogonal to each other; and 3: the velocity of a signal data stream acquired after theshift of the frequency spectrum is F1, the signals are subjected to extraction filtering for M times by using a CIC extraction filter to acquire an I baseband signal and a Q baseband signal with the velocity of F1 / M, and the baseband signals are subjected to complementary filtering respectively by using an FIR low-pass filter.

Description

technical field [0001] The invention belongs to the technical field of radar reception, in particular to down-conversion and processing of broadband signal reception. The present invention also relates to related broadband signal reception and processing techniques for wireless communication. Background technique [0002] The idea of ​​software radio is a brand-new design idea that appeared after the 1990s. Its core is to load different communication software on a common communication platform to realize the conversion between different communication methods. An ideal software radio platform is to directly sample the analog signal received by the antenna after amplifying, so as to realize complete programmability. All subsequent signal processing, including down-conversion frequency mixing, band-pass filtering, carrier extraction, IQ demodulation, etc., are processed in the subsequent DSP\FPGA chip. At present, the final recognized standard of software radio has not yet fo...

AI Technical Summary

Problems solved by technology

Traditional digital down-conversion mostly uses dedicated chips, most of its functions have been solidified, and the compatibility is poor

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