Noise suppressor circuit and associated method for suppressing periodic interference component portions of a communication signal
First Claim
1. A noise suppressor for suppressing selected noise component portions of a receive signal having an informational component portion, said noise suppressor comprising:
- a noise component estimator coupled to receive at least a signal indicative of the receive signal, said noise component estimator for estimating time-domain periodic noise component portions of the receive signal which are generated by at least one source of periodic interference and for generating a time-domain noise component estimate signal responsive thereto, said noise component estimator including an autocorrelator for correlating the signal indicative of the received signal with the signal indicative of the received signal delayed by a plurality of delay periods, the autocorrelator further for generating a plurality of autocorrelation signals of values indicator of autocorrelations therebetween, said noise component estimator further including a sorter coupled to receive the autocorrelation signals, the sorter for determining which of the autocorrelation signals applied thereto, and the time delay associated therewith, correlates most closely with the signal indicative of the received signal, and for generating a delay amount signal responsive thereto; and
a noise component subtractor coupled to receive the signal indicative of the receive signal and to receive the time-domain noise component estimate signal generated by said noise component estimator, said noise component subtractor for subtracting values of the time-domain noise component estimate signal from the signal indicative of the receive signal and for forming a noise-suppressed signal responsive thereto, the noise-suppressed signal representative of the receive signal in which the noise component portions generated by the source of periodic interference are suppressed.
3 Assignments
0 Petitions
Accused Products
Abstract
A noise suppressor, and associated method, suppresses periodic noise components of a communication signal. The period of the periodic noise components of the communication signal is determined by correlating the communication signal with the communication signal, delayed by various delay amounts. Once the period of the noise component portion is determined, a periodic signal exhibiting a corresponding periodicity is generated and subtracted from the communication signal. The resultant, difference signal forms a noise-suppressed communication signal. When embodied in a radiotelephonic device, background noise formed of an engine sound caused by the running engine of a motor vehicle at which the radiotelephonic device is operated can be suppressed during operation of the noise suppressor.
80 Citations
13 Claims
-
1. A noise suppressor for suppressing selected noise component portions of a receive signal having an informational component portion, said noise suppressor comprising:
-
a noise component estimator coupled to receive at least a signal indicative of the receive signal, said noise component estimator for estimating time-domain periodic noise component portions of the receive signal which are generated by at least one source of periodic interference and for generating a time-domain noise component estimate signal responsive thereto, said noise component estimator including an autocorrelator for correlating the signal indicative of the received signal with the signal indicative of the received signal delayed by a plurality of delay periods, the autocorrelator further for generating a plurality of autocorrelation signals of values indicator of autocorrelations therebetween, said noise component estimator further including a sorter coupled to receive the autocorrelation signals, the sorter for determining which of the autocorrelation signals applied thereto, and the time delay associated therewith, correlates most closely with the signal indicative of the received signal, and for generating a delay amount signal responsive thereto; and a noise component subtractor coupled to receive the signal indicative of the receive signal and to receive the time-domain noise component estimate signal generated by said noise component estimator, said noise component subtractor for subtracting values of the time-domain noise component estimate signal from the signal indicative of the receive signal and for forming a noise-suppressed signal responsive thereto, the noise-suppressed signal representative of the receive signal in which the noise component portions generated by the source of periodic interference are suppressed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
Specification