Patents by Inventor Kwang Eun Ahn
Kwang Eun Ahn has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7340005Abstract: A signal transmission apparatus comprises a plurality of look-up tables (LUTs) corresponding to operation areas of a nonlinear transmission device, an operational characteristic calculator, a LUT selector, and a predistorter. The LUTs are adapted to store gain values of input signal magnitudes. The LUT selector selects a LUT corresponding to a calculated operational characteristic. The selected LUT generates a gain value output signal. The predistorter generates a predistorted signal from the gain value output signal and an input signal. The predistorted signal is input to a nonlinear transmission device.Type: GrantFiled: June 3, 2004Date of Patent: March 4, 2008Assignee: LG Electronics Inc.Inventors: Wang-Rae Kim, Kwang-Eun Ahn, Woo-Sik Kim
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Patent number: 7116167Abstract: A predistortion linearizer may include a digital signal processor (DSP) for modeling a nonlinear characteristic of a high power amplifier (HPA) on a real time basis; a distortion signal generator for generating a distortion signal by using the signal modeled by the DSP; and a main path unit for combining the output signal of the HPA and the distortion signal of the distortion signal generator and transmitting an input signal without a distortion component. Since the nonlinear characteristic of the power amplifier is modeled on a real time basis to remove the distortion component contained in the output signal of the power amplifier, the nonlinear characteristic of the power amplifier is improved, and thus, an efficiency of the power amplifier can be maximized.Type: GrantFiled: July 20, 2001Date of Patent: October 3, 2006Assignee: LG Electronics Inc.Inventor: Kwang-Eun Ahn
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Patent number: 6973139Abstract: A base station transmitter having a digital predistorter and predistortion method is disclosed. The predistortion is accomplished by delaying a digital input signal, predistorted by a predistortion unit, for a predetermined time. A coefficient of a non-linear characteristic model of a power amplifier is generated using a digital output signal, converted from an amplified output signal of the power amplifier, and the delayed digital input signal. A reference signal is randomly generated to produce a predistortion model having a characteristic opposite to the non-linear characteristic of the power amplifier. A predistortion error function is extracted by subtracting the reference signal and the non-linear characteristic model of the power amplifier, after the produced coefficient is applied to the model. A coefficient of the predistortion unit is controlled adaptively using the predistortion error function.Type: GrantFiled: December 21, 2001Date of Patent: December 6, 2005Assignee: LG Electronics Inc.Inventors: Kwang-Eun Ahn, Woo-Sik Kim
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Publication number: 20040252783Abstract: A signal transmission apparatus comprises a plurality of look-up tables (LUTs) corresponding to operation areas of a nonlinear transmission device, an operational characteristic calculator, a LUT selector, and a predistorter. The LUTs are adapted to store gain values of input signal magnitudes. The LUT selector selects a LUT corresponding to a calculated operational characteristic. The selected LUT generates a gain value output signal. The predistorter generates a predistorted signal from the gain value output signal and an input signal. The predistorted signal is input to a nonlinear transmission device.Type: ApplicationFiled: June 3, 2004Publication date: December 16, 2004Applicant: LG Electronics Inc.Inventors: Wang-Rae Kim, Kwang-Eun Ahn, Woo-Sik Kim
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Patent number: 6522198Abstract: A power amplifier having a predistortion linearizer for improving the non-linear property of the power amplifier is disclosed. The powers amplifier includes a predistorter for outputting a distortion compensating signal to the high power amplifier, a delay line for delaying an input signal for a prescribed period of time and outputting a reference signal, a distortion component detection circuit for detecting a distortion component by comparing the output signal of the power amplifier with the reference signal of the delay line, and an adaptive controller for controlling the properties of the predistorter in order to minimize the detected distortion component.Type: GrantFiled: December 14, 2000Date of Patent: February 18, 2003Assignee: LG Electronics Inc.Inventor: Kwang Eun Ahn
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Publication number: 20020080891Abstract: A base station transmitter having a digital predistorter and predistortion method is disclosed. The predistortion is accomplished by delaying a digital input signal, predistorted by a predistortion unit, for a predetermined time. A coefficient of a non-linear characteristic model of a power amplifier is generated using a digital output signal, converted from an amplified output signal of the power amplifier, and the delayed digital input signal. A reference signal is randomly generated to produce a predistortion model having a characteristic opposite to the non-linear characteristic of the power amplifier. A predistortion error function is extracted by subtracting the reference signal and the non-linear characteristic model of the power amplifier, after the produced coefficient is applied to the model. A coefficient of the predistortion unit is controlled adaptively using the predistortion error function.Type: ApplicationFiled: December 21, 2001Publication date: June 27, 2002Applicant: LG ElectronicsInventors: Kwang-Eun Ahn, Woo-Sik Kim
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Publication number: 20020012404Abstract: A predistortion linearizer includes: a digital signal processor (DSP) for modeling a nonlinear characteristic of a high power amplifier (HPA) on a real time basis; a distortion signal generator for generating a distortion signal by using the signal modeled by the DSP; and a main path unit for combining the output signal of the HPA and the distortion signal of an error generator and transmitting an input signal without a distortion component. Since the nonlinear characteristic of the power amplifier is modeled on a real time basis to remove the distortion component contained in the output signal of the power amplifier, the nonlinear characteristic of the power amplifier is improved, and thus, an efficiency of the power amplifier can be maximized.Type: ApplicationFiled: July 20, 2001Publication date: January 31, 2002Applicant: LG Electronics Inc.Inventor: Kwang-Eun Ahn
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Publication number: 20010052816Abstract: A power amplifier having a predistortion linearizer for improving the non-linear property of the power amplifier is disclosed. The powers amplifier includes a predistorter for outputting a distortion compensating signal to the high power amplifier, a delay line for delaying an input signal for a prescribed period of time and outputting a reference signal, a distortion component detection circuit for detecting a distortion component by comparing the output signal of the power amplifier with the reference signal of the delay line, and an adaptive controller for controlling the properties of the predistorter in order to minimize the detected distortion component.Type: ApplicationFiled: December 14, 2000Publication date: December 20, 2001Applicant: LG Electronics Inc.Inventor: Kwang Eun Ahn
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Patent number: 6211734Abstract: An active distortion signal generating circuit for removing linear distortions in a power amplifier includes a linear processing circuit that receives a linear path signal and outputs a linear signal; a nonlinear processing circuit that receives a nonlinear path signal and outputs a distortion signal; and an output circuit that adds the linear signal and the distortion signal to obtain a first sum signal, that adds the first sum signal to a duplicate first sum signal to obtain a second sum signal and that generates control signals utilizing the linear signal, the distortion signal, the first sum signal and the second sum signal; and a variable attenuator and phase shifter that adjusts the distortion signal based upon the control signals. The active distortion signal generating circuit compensates the amplitude and phase errors of the input signal such that no input signal component appears at the output of the active distortion signal generating circuit.Type: GrantFiled: November 30, 1999Date of Patent: April 3, 2001Assignee: LG Information & Communications, Ltd.Inventor: Kwang Eun Ahn