Demodulator based on orthogonal frequency division multiplexing in DRM receiver

Abstract

The invention discloses a demodulator which is based on orthogonal frequency division multiplexing and is used in a DRM receiver. The demodulator is provided with a controller which controls the work uniformly, and the controller is connected with an on-chip memory cell, a reordering unit, a calculator, a twiddle factor unit and a butterfly unit; the controller reorders the source operands that are sequentially input by the reordering unit according to an FFT arithmetic type and a mixed basis decomposition, and stores the reordered operands in the on-chip memory cell; the controller reads theoperands from the on-chip memory cell and obtains a twiddle factor by computation by the twiddle factor unit according to the mixed basis decomposition; then the butterfly unit performs butterfly computation, and finally the obtained operands are written back to the on-chip memory cell. The demodulator has the advantages of meeting the DRM standard and supporting four OFDM parameters in terms of design; compared with the implementation of the existing software, the demodulator has low cost and low power consumption, uses 32-bit single precision floating-point number to describe the internal data at high precision, and can implement high-precision OFDM demodulation.

Description

technical field [0001] The invention relates to a demodulator used in a DRM (Digital Radio Mondiale, digital amplitude modulation broadcasting) receiver, in particular to a demodulator supporting four orthogonal frequency division multiplexing parameters stipulated in the DRM standard. Background technique [0002] AM (Amplitude Modulation, amplitude modulation, also known as amplitude modulation) broadcasting has been used since the first experimental broadcasting by Reginald Fessenden in 1906. It includes shortwave (Shortwave), medium wave (Medium wave), long wave (Longwave) below 30Mhz wave) three frequency bands, due to the relatively simple modulation and transmission methods of AM broadcasting, the corresponding receivers are relatively cheap and very popular, but it also causes the signal to be very susceptible to interference, multi-path propagation, Doppler effect and electronic interference etc. will seriously attenuate the signal quality, the sound quality receive...

AI Technical Summary

Problems solved by technology

Although these two DRM receivers have realized the reception of DRM broadcasts, these two DRM receivers are relatively large in size, high in power consumption, and very expensive, and cannot realize mobile reception. There is an urgent need for a dedicated decoding chip on the market to reduce the Cost and power consumption of the entire DRM receiver

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