Device and method for recovering frequency redundant data in a network communications receiver
AssigneeAdvanced Micro Devices, Inc.
InventorsChien-Meen Hwang, Eugen Gershon
Life of this patent
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Abstract
A demodulation circuit for recovering frequency redundant quadrature amplitude modulated data comprises an A/D converter generating digitized carrier signal. A mixer receives the digitized carrier and generates a frequency shifted I-signal and a frequency shifted Q-signal. A bank of filters includes a narrow band filter centered at each one of a plurality frequency shifted sub-spectra to generate a digital data signal for each sub-spectrum. A selection circuit determines which one of the sub-spectrum data signals is the strongest and a receiver circuit recovers the transmitted data in response to the strongest sub spectrum data signal.
Claims16
A demodulation circuit comprising:
- a) an A/D converter generating a series of samples representing a frequency diverse modulated carrier including redundant data transmitted in a plurality of sub-spectra;
- b) a mixer receiving the series of samples and generating frequency shifted I-signal and a frequency shifted Q-signal representing redundant data in a plurality of frequency shifted sub-spectra;
- c) a filter bank including a plurality of narrow band filters, each centered at one of a plurality of the frequency shifted sub-spectra, each receiving the frequency shifted I-signal and the frequency shifted Q-signal, and each generating a sub-spectrum data signal comprising a sub spectrum I-signal and a sub-spectrum Q-signal;
- d) a selection circuit determining which one of the sub-spectrum data signals is the strongest sub-spectrum data signal;
- and
- e) a receiver circuit generating digital data in response to the strongest sub spectrum data signal.
A method of recovering data from a frequency diverse modulated carrier comprising:
- a) generating a series of digital samples representing redundant data transmitted in a plurality of sub-spectra of a frequency diverse modulated carrier;
- b) mixing the series of digital samples with a digital sine waveform and a digital cosine waveform to generate a frequency shifted I-signal and a frequency shifted Q-signal representing redundant data in a plurality of frequency shifted sub-spectra;
- c) filtering the frequency shifted I-signal and the frequency shifted Q-signal with a filter bank including a plurality of narrow band filters, each centered at one of a plurality of the frequency shifted sub-spectra to generate a plurality of sub-spectrum data signals, comprising a sub spectrum I-signal and a sub-spectrum Q-signal, each corresponding to one of the frequency shifted sub-spectra;
- d) determining which one of the sub-spectrum data signals is the strongest sub-spectrum data signal;
- and
- e) recovering digital data in response to the strongest sub spectrum data signal.
Dependencies are inferred from the claim text.