Patent application number | Description | Published |
20120275545 | DISTORTION COMPENSATION APPARATUS AND DISTORTION COMPENSATION METHOD - A distortion compensation apparatus for performing distortion compensation processing by applying the inverse properties of distortion properties of said power amplifier to a transmission signal to be input to a power amplifier, includes a plurality of distortion compensation coefficient storage units configured to store a plurality of distortion compensation coefficients used for said distortion compensation processing, an offset correction processing unit configured to subject said distortion compensation coefficient stored in each of said plurality of distortion compensation coefficient storage units to offset correction processing, and to generate distortion compensation coefficients in the case that said offset correction processing has not been performed, corresponding to said plurality of distortion compensation coefficient storage units, in a pseudo manner and a distortion compensation processing unit configured to subject said transmission signal to said distortion compensation processing based on said distortion compensation coefficients generated in a pseudo manner. | 11-01-2012 |
20120288030 | DISTORTION COMPENSATION DEVICE AND DISTORTION COMPENSATING METHOD - A distortion compensation device which reduces a distortion of an amplifier which is added to an output signal of the amplifier, the distortion compensation device including: a plurality of distortion compensation coefficient storage circuits which stores a plurality of distortion compensation coefficients and outputs the distortion compensation coefficients according to an amplitude of an input signal of the amplifier, a distortion compensating processing circuit which adds the distortion compensation coefficient output from each of the plurality of distortion compensation coefficient storage circuits to the input signal of the amplifier, and a distortion compensation coefficient updating circuit which performs weighting processing on the distortion compensation coefficient output from each of the plurality of distortion compensation coefficient storage circuits to reduce the distortion compensation coefficient and which calculates an update value of the distortion compensation coefficient by using the distortion compensation coefficient which is subjected to the weighting processing. | 11-15-2012 |
20130015917 | DISTORTION COMPENSATION APPARATUS, TRANSMITTER, AND DISTORTION COMPENSATION METHODAANM ISHIKAWA; HiroyoshiAACI YokohamaAACO JPAAGP ISHIKAWA; Hiroyoshi Yokohama JPAANM Nagatani; KazuoAACI YokohamaAACO JPAAGP Nagatani; Kazuo Yokohama JPAANM Fudaba; NobukazuAACI YokohamaAACO JPAAGP Fudaba; Nobukazu Yokohama JP - A distortion compensation apparatus includes an amplifying unit, a plurality of distortion compensation coefficient storage units, a first address generating unit, a second address generating unit, and a distortion compensating unit. The amplifying unit amplifies an input signal. A plurality of distortion compensation coefficient storage units store the distortion compensation coefficients for compensating for the distortion of the amplifying unit by being associated with two different addresses. The first address generating unit generates a first address based on the current input signal. The second address generating unit generates a second address different from the first address based on the previous input signal. The distortion compensating unit obtains the distortion compensation coefficient corresponding to a combination of the first and second addresses from each of the distortion compensation coefficient storage units and performs a pre-distortion processing for the current input signal to the amplifying unit using the obtained distortion compensation coefficient. | 01-17-2013 |
20130040587 | DISTORTION COMPENSATION DEVICE, DISTORTION COMPENSATION METHOD, AND RADIO TRANSMITTER - A distortion compensation device includes: a frequency-characteristic adding unit configured to add a frequency characteristic to an error signal to generate an added error signal, the error signal being a difference between an input signal input to an amplifier and an output signal output from the amplifier; a distortion-compensation-coefficient updating unit configured to update a distortion compensation coefficient for compensating for a distortion characteristic of the amplifier based on the added error signal; and a distortion compensation unit configured to perform distortion compensation on the input signal using the updated distortion compensation coefficient. | 02-14-2013 |
20130321078 | DISTORTION COMPENSATION APPARATUS AND DISTORTION COMPENSATION METHOD - A distortion compensation apparatus including: a processor configured to generate a pre-distortion signal by compensating an input signal for a distortion based on a distortion compensation coefficient and a plurality of delayed signals obtained by delaying the input signal by a plurality of amounts of delay, and an amplifier configured to generate an amplified signal by amplifying the pre-distortion signal, wherein the processor calculates the distortion compensation coefficient based on the input signal, the pre-distortion signal, and the amplified signal, and calculates the plurality of amounts of delay based on the amplified signal. | 12-05-2013 |
20140072074 | ADDRESS CONTROLLER, TRANSMITTER, AND ADDRESS CONTROL METHOD - An address controller includes: a plurality of lookup tables configured to hold values corresponding to a plurality of addresses; a similarity detector configured to detect similarity between the plurality of lookup tables and to group similar lookup tables among the plurality of lookup tables; and a controller configured to read the values out of the plurality of lookup tables grouped by the similarity detector, using address control information common to grouped lookup tables. | 03-13-2014 |
20140146910 | DELAY QUANTITY ESTIMATION APPARATUS AND DELAY QUANTITY ESTIMATION METHOD - A delay quantity estimation apparatus comprises a first correlation value arithmetic unit to calculate a first correlation value as a correlation value between a first input signal and a feedback signal delayed with a first delay value; a second correlation value arithmetic unit to calculate a second correlation value as a correlation value between the first input signal and a feedback signal delayed with a second delay value; and a delay quantity estimation unit to estimate a delay quantity of the feedback signal with respect to the input signal on the basis of the first difference value as a difference between the first correlation value and the second correlation value, wherein the second delay value is a value given by adding a certain value to the first delay value. | 05-29-2014 |
20140167844 | DISTORTION COMPENSATION DEVICE AND DISTORTION COMPENSATION METHOD - A distortion compensation device includes: a distortion compensator configured to output, to a power amplifier, a predistortion signal obtained by performing distortion compensation processing on a transmission signal by using a distortion compensation coefficient, wherein the distortion compensator limits bands of a reference signal and a feedback signal so that the bands fall in a pass band and updates the distortion compensation coefficient based on an error between the reference signal and the feedback signal, the reference signal corresponding to the predistortion signal, the feedback signal corresponding to an output feedback of the power amplifier. | 06-19-2014 |
20140197885 | AMPLIFYING DEVICE, DISTORTION COMPENSATING DEVICE, AND AMPLIFYING METHOD - An amplifying device including: a first amplifier configured to generate a first output signal by amplifying an input signal, a second amplifier configured to generate a second output signal by amplifying the first output signal, and a processor configured to perform a first compensation by compensating a distortion for the second amplifier in accordance with the first output signal and the second output signal. | 07-17-2014 |
20140292405 | AMPLIFICATION DEVICE AND AMPLIFICATION METHOD - An amplification device includes: an amplitude adjustment circuit configured to adjust an amplitude level of an input signal so as to keep the amplitude level within a given range; an amplifier configured to amplify the adjusted signal; and a circuitry configured to change an amplitude level of the amplified signal, based on the amplitude level of the input signal and a first distortion compensation corresponding to the amplitude level of the input signal. | 10-02-2014 |
20140347132 | POWER AMPLIFIER APPARATUS, TRANSMITTER APPARATUS, AND METHOD OF CONTROLLING THE POWER AMPLIFIER APPARATUS - A power amplifier apparatus includes an amplifier configured to amplify an input signal converted into an analog signal, a distortion compensator circuitry configured to perform a pre-distortion process to an input signal at a second sampling rate higher than a first sampling rate at which the input signal is converted into an analog signal, a remover configured to remove a frequency component exceeding a frequency band corresponding to the first sampling rate from the input signal subjected to the pre-distortion process, a first rate converter configured to convert a sampling rate of the input signal from which the frequency component is removed from the second sampling rate to the first sampling rate, and a first signal converter configured to convert the input signal the sampling rate of which is converted into an analog signal at the first sampling rate to supply the input signal converted into the analog signal to the amplifier. | 11-27-2014 |