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US 8,150,346 B2Granted
Detecting a signal in the presence of noise
AssigneeSilicon Laboratories Inc.
InventorsJavier Elenes, Dana Taipale
Life of this patent
Estimating the term…
Abstract
In one embodiment, the present invention includes a method for receiving an incoming radio frequency (RF) signal in a receiver, estimating a signal-to-noise ratio (SNR) of a constant modulus (CM) signal in the incoming RF signal based on a calculated magnitude of the incoming RF signal, and indicating presence of a modulated signal in the incoming RF signal if the estimated SNR is greater than a threshold.
Claims21
A method comprising:
- receiving an incoming radio frequency (RF) signal in a receiver;
- providing the incoming RF signal to an estimator to estimate a signal-to-noise ratio (SNR) of a signal at a first candidate frequency in the incoming RF signal without demodulating the incoming RF signal based on a calculated magnitude for each of a plurality of samples of the incoming RF signal;
- and
- indicating presence of a modulated signal corresponding to the signal at the first candidate frequency in the incoming RF signal if the estimated SNR is greater than a threshold and indicating non-presence of the modulated signal if the estimated SNR is less than the threshold.
1 more element
An apparatus comprising:
- a transceiver to receive and transmit radio signals, the transceiver including:
- a receiver having a low noise amplifier (LNA) to amplify an incoming radio frequency (RF) signal;
- a mixer to downconvert the RF signal to a second frequency signal;
- a digitizer coupled to the mixer to digitize the second frequency signal;
- a processor coupled to the digitizer to process the digitized second frequency signal, wherein the processor is to determine presence of a signal in the incoming RF signal at a candidate frequency without demodulation of the signal, based on a calculated magnitude for each of N samples of the incoming RF signal, the processor comprising a digital signal processor (DSP) to perform a coordinate rotation digital computer (CORDIC) operation to determine the calculated magnitude;
- and
- a demodulator coupled to the processor to demodulate a signal present in the incoming RF signal in a receive mode of operation.
4 more elements
A system comprising:
- a transceiver to receive and transmit radio signals, the transceiver including:
- a receiver having an amplifier to amplify an incoming radio frequency (RF) signal;
- a mixer to downconvert the RF signal to an intermediate frequency (IF) signal;
- an analog-to-digital converter (ADC) coupled to the mixer to digitize the IF signal;
- a digital signal processor (DSP) coupled to the ADC to process the digitized IF signal, wherein the DSP is to perform a blind scan detection for a signal in the incoming RF signal at a candidate frequency without demodulation of the signal, based on a comparison of an estimated signal-to-noise ratio (SNR) of the signal obtained from a calculated magnitude for each of a plurality of samples of the signal to a threshold and the transceiver is to detect a signal having a SNR of less than 0 decibels;
- and
- a demodulator coupled to the DSP to demodulate a signal present in the incoming RF signal in a receive mode of operation;
- a host processor coupled to the transceiver to instruct the transceiver to perform the blind scan detection;
- and
- a non-volatile storage to store digital audio content.
7 more elements
Dependencies are inferred from the claim text.