Patents Assigned to Bitwave Pte. Ltd.
-
Patent number: 7647077Abstract: The present invention provides a wireless headset with echo control and noise cancellation. The present invention also provides a method with phase reversion for echo control of a wireless headset wherein the wireless headset comprises closely disposed speakers and acoustic sensors. The present invention further provides a method with beamforming for noise cancellation of a wireless headset wherein the wireless headset comprises two separate units disposed in distance, and wherein each unit comprises an acoustic sensor.Type: GrantFiled: May 29, 2006Date of Patent: January 12, 2010Assignee: Bitwave Pte LtdInventors: Siew Kok Hui, Eng Sui Tan, Kok Heng Loh
-
Patent number: 7289586Abstract: A method of processing signals received from an array of sensors includes sampling and digitally converting the received signals. The digitally converted signals are processed to provide an output signal, the processing including filtering the signals using a first adaptive filter that enhances a target signal of the digitally converted signals and a second adaptive filter that suppresses an unwanted signal of the digitally converted signals, and processing the filtered signals in a frequency domain to further suppress the unwanted signal. The digitally converted signals are processed to determine a direction of arrival of the target signal, the processing including filtering the signals using a third adaptive filter.Type: GrantFiled: December 5, 2005Date of Patent: October 30, 2007Assignee: Bitwave Pte Ltd.Inventor: Siew Kok Hui
-
Publication number: 20060270468Abstract: The present invention provides a wireless communication system with echo control and noise cancellation. The present invention also provides a method with phase reversion for echo control of a wireless communication system wherein the wireless communication system comprises closely disposed speakers and acoustic sensors. The present invention further provides a method with beamforming for noise cancellation of a wireless communication system wherein the wireless communication system comprises two separate units disposed in distance, and wherein each unit comprises an acoustic sensor.Type: ApplicationFiled: May 29, 2006Publication date: November 30, 2006Applicant: Bitwave Pte LtdInventors: Siew Kok Hui, Eng Tan, Kok Loh
-
Publication number: 20060072693Abstract: A method of processing signals received from an array of sensors includes sampling and digitally converting the received signals. The digitally converted signals are processed to provide an output signal, the processing including filtering the signals using a first adaptive filter that enhances a target signal of the digitally converted signals and a second adaptive filter that suppresses an unwanted signal of the digitally converted signals, and processing the filtered signals in a frequency domain to further suppress the unwanted signal. The digitally converted signals are processed to determine a direction of arrival of the target signal, the processing including filtering the signals using a third adaptive filter.Type: ApplicationFiled: December 5, 2005Publication date: April 6, 2006Applicant: Bitwave Pte Ltd.Inventor: Siew Hui
-
Patent number: 6999541Abstract: A method of processing signals received from an array of sensors is disclosed comprising the steps of sampling and digitally converting the received signals and processing the digitally converted signals to provide an output signal, the processing including filtering the signals using a first adaptive filter arranged to enhance a target signal of the digitally converted signals and a second adaptive filter arranged to suppress an unwanted signal of the digitally converted signals and processing the filtered signals in the frequency domain to suppress the unwanted signal further.Type: GrantFiled: November 12, 1999Date of Patent: February 14, 2006Assignee: Bitwave Pte Ltd.Inventor: Siew Kok Hui
-
Patent number: 6249581Abstract: The present echo canceller utilizes the principle that the spectrum pattern of human speech does not change much in the short run. The inputs to the present echo canceller are x(t) and y(t), y(t) representing the incoming speech signal from a far-end speaker and x(t) representing the combination of speech signal from a near-end speaker and the echo. The processed forms of the input x(t) and y(t) are processed by applying the well-known Hanning window. They are then transformed into their respective frequency domain using the well-known fast Fourier transform (FFT), and the power spectrum Px and Py are calculated where Px=|xr(f)|+|xi(f)|+&egr;*|xr(f)|*|xi(f)| and Py=|yr(f)|+|yi(f)|+&egr;*|yr(f)|*|yi(f)| where &egr; is a scaling factor which controls the amount of echo to be suppressed, and converting Px and Py to bark scales Px(b) and Py(b).Type: GrantFiled: July 29, 1998Date of Patent: June 19, 2001Assignee: Bitwave Pte. Ltd.Inventor: Hui Siew Kok