Device and method for adjusting input gain for multiple signal formats in a data network
AssigneeAdvanced Micro Devices, Inc.
InventorColin D. Nayler
Life of this patent
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Abstract
A network receiver is configured for receiving a modulated carrier signal from another network transceiver via a network medium, the modulated carrier signal may be either a pulse position modulated (PPM) carrier or a quadrature amplitude modulated (QAM) carrier. The network receiver is configured to select an optimal gain setting for the input amplifier corresponding to whether the modulated carrier is PPM or QAM.
Claims22
A network receiver configured for receiving a modulated carrier signal from another network transceiver via a network medium, the network receiver comprising:
- a) an input amplifier for amplifying a received modulated carrier signal according to one of a plurality of amplifier gain settings and outputting an amplified carrier signal;
- b) an envelope detector configured for outputting an envelope signal in response to the amplified carrier signal;
- c) a first gain control circuit configured to select a first gain setting in response to the envelope signal, the first gain setting being optimal for receiving a pulse position modulated carrier signal;
- d) a second gain control circuit configured to select a second gain control setting in response to the envelope signal, the second gain setting being optimal for receiving a quadrature amplitude modulated signal;
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- e) selection circuitry configured to determine whether the envelope signal represents a pulse position modulated carrier or an amplitude modulated carrier and sets the amplifier gain setting to the first gain setting or a second gain setting respectively.
A method of determining a gain setting for an input amplifier generating an amplified carrier signal in a receiver configured for receiving a modulated carrier signal from a network medium, the method comprising:
- a) generating an envelope signal from the amplified carrier signal representing the amplified carrier signal power;
- b) determining a first gain setting in response to the envelope signal, the first gain setting selected for receiving a pulse position modulated carrier signal;
- c) determining a second gain setting in response to the envelope signal, the second gain setting selected for receiving a quadrature amplitude modulated carrier signal;
- d) determining whether the modulated carrier signal is a pulse position modulated carrier or a quadrature amplitude modulated carrier;
- and
- e) setting the gain of the input amplifier to the first gain setting if the modulated carrier signal is determined to be a pulse position modulated carrier and setting the input amplifier gain to the second gain setting if the modulated carrier signal is determined to be a quadrature amplitude modulated carrier.
A network receiver configured for receiving a modulated carrier signal from another network transceiver via a network medium, the network receiver comprising:
- a) an input amplifier for amplifying a received modulated carrier signal according to one of a plurality of amplifier gain settings and outputting an amplified carrier signal;
- b) a first gain control circuit for providing a first amplifier gain setting based on a carrier signal modulated in accordance with a first modulation method;
- c) a second gain control circuit for providing a second amplifier gain setting based on a carrier signal modulated in accordance with a second modulation method;
- d) a selection circuit for analyzing the carrier signal and automatically identifying whether the carrier signal is modulated in accordance with the first modulation method or the second modulation method, and for providing a gain control signal to the input amplifier to amplify the carrier signal with either the first amplifier gain setting or the second amplifier gain setting based on the modulation method identified by the selection circuit, wherein the selection circuit includes envelope detection circuitry for detecting the duration of a power pulse in the envelope signal, and wherein the selection circuit provides a gain control signal coupling the first amplifier gain setting to the input amplifier if the duration of a power pulse is less than a duration on the order of a duration of a pulse position modulation power pulse.
Dependencies are inferred from the claim text.