Polyphase decomposition based variable point number fast Fourier transform method for GHz high-speed sampling signal

Abstract

The invention proposes a polyphase decomposition based variable point number fast Fourier transform (FFT) method for a GHz high-speed sampling signal. A conventional FFT processing method is decomposed and the FFT processing of the high-speed sampling signal is decomposed into the processing of a plurality of low-speed signals through a time domain polyphase decomposition technology, so that a possibility is provided for the FFT processing of the high-speed sampling signal; and after the conventional FFT processing method is decomposed into the processing of the low-speed signals in the polyphase manner, low-speed processing results are subjected to weighted synthesis to obtain a final high-speed sampling signal FFT processing result. According to the method, a new polyphase twiddle factor is established, so that the final FFT result is obtained through simple pipelining multiplication and summation operations.

Description

technical field [0001] The invention relates to the field of signal processing, in particular to a variable-point fast Fourier transform method for high-speed sampling signals. Background technique [0002] The fast Fourier transform (FFT) technology of high-speed sampling signal is one of the key technologies of broadband high-speed sampling signal processing. When the data rate of the signal reaches more than GHz, the traditional FFT method can no longer meet the requirements of hardware processing speed. Therefore, the FFT technology of high-speed sampling signal has been a hot direction of signal processing at home and abroad. Researchers at home and abroad have proposed some FFT technologies for high-speed sampling signals. Currently, the most commonly used is the high-speed sampling signal DFT technology based on two-dimensional discrete Fourier transform reported by RFEL. The basic principles are: [0003] Suppose the length of the sequence x(n) is L, and L is a nat...

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Problems solved by technology

[0014] (1) This technology requires two DFT processes, which not only requires a large amount of calculation, but also makes it difficult to implement because of the complexity of the technology, and it also takes up a lot of resources;

[0015] (2) After this FFT processing technology is implemented on the hardware platform, the number of FFT points cannot be changed arbitrarily. When the parameter M is changed, the number of output interfaces will not match the subsequent modules. Therefore, when this FFT processing technology is used in practice, poor flexibility

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