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DRX-1 Digital Radio Receiver
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The DRX-1 is a DC to 1.0 MHz digital radio receiver.
The DRX-1 directly samples the RF input signal using a 16-bit analog to digital convertor (ADC).
The ADC feeds a digital down converter (DDC), which tunes the receiver to the required centre frequency and reduces
the sample rate by decimation. The DDC feeds the DSP for additional decimation,
audio filtering
and demodulation.
- A powerful 32-bit 180 MFLOPs floating-point
DSP (Analog Devices SHARC ADSP-21065L) allows precision FIR
filtering with a 100 dB min filter stopband and
linear demodulation minimises distortion products. Addition filtering of the
demodulated audio signal by an adaptive-filter
attenuates extraneous background noise, to further improve the
clarity of reception.
DRX-1 Digital Radio Receiver Description
SHARC DSP Radio Library
- A set of DSP Radio Library functions
implemented on the SHARC ADSP-2106x, which performs
DSP demodulation on baseband IQ components and FIR Filtering
operations on audio and speech signals. The filtering is aimed at
filtering the demodulated audio (e.g. from short-wave receivers)
to improve the clarity of reception. Different filtering modes
are aimed at Speech (Single Side Band, SSB, NBFM), Music
(Amplitude Modulation, AM), Morse Code (Continuous Wave, CW) and
Data (AM). The 32-bit floating-point DSP allows filtering with a
-100 dB minimum stopband, a figure unobtainable from 16-bit
fixed-point DSPs.
- The DSP Radio Library is supplied with
documentation and DSP example code. The full DSP source code is
available.
SHARC DSP Radio Library Description
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