| Patent application number | Description | Published |
|---|
| 20100271124 | Distortion Compensation Device - A distortion in an amplified signal obtained by amplifying a first input signal, is compensated for by applying a correction factor to the first input signal. The correction factor is updated based on the first input signal and the amplified signal. Updating the correction factor is prohibited when a value of the first input signal is same as a value of a second input signal among a plurality of input signals input previous to the first input signal. | 10-28-2010 |
| 20100310007 | Filter Device - An input signal to a filter device is allowed to be written into one of a plurality of sequentially connected cells if the input signal is not the zero-valued sample. Each cell receives the input signal and multiplies the input signal by one of a plurality of weight coefficients. The input signal is stopped to be written into any of the cells if the input signal is the zero-valued sample. A result of a filtering operation is output from the last cell. | 12-09-2010 |
| 20100323638 | PHASE CORRECTOR AND PHASE CORRECTION METHOD - A phase corrector in a radio transmitter includes a quadrature modulator which modulates a first carrier signal by using an in-phase component and a quadrature component of a first signal, a quadrature demodulator which demodulates a feedback signal by using a second carrier signal to generate a second signal including an in-phase component and a quadrature component, a phase detector which detects a phase error between the first signal and the second signal based on the in-phase components and the quadrature components of the first signal and the second signal, and a phase shifter which performs phase shift of any one of the first signal, the second signal, the first carrier signal and the second carrier signal based on a sum value obtained by adding to the phase error a first phase amount varying on a time base in a given phase range. | 12-23-2010 |
| 20100323639 | PHASE CORRECTION APPARATUS AND PHASE CORRECTION METHOD - A phase correction apparatus in a wireless transmitter includes a modulator for modulating a first carrier signal by an in-phase component and a quadrature-phase component of a first signal, a demodulator for demodulating a returned signal by a second carrier signal and generating a second signal including an in-phase component and an quadrature-phase component, a phase detector for detecting a phase error between the first signal and the second signal based on the in-phase components and the quadrature-phase components of the first and second signals, and a phase shifter group for performing a phase shift based on the phase error, the phase shifter group including a first phase shifter for performing a phase shift on any of the first signal, the second signal, the first carrier signal, and the second carrier signal and a second phase shifter for shifting a phase of the first signal. | 12-23-2010 |
| 20100323640 | PHASE CORRECTION APPARATUS AND PHASE CORRECTION METHOD - A phase correction apparatus in a wireless transmitter includes a modulator configured to modulate an in-phase component and a quadrature component of a first signal by a first carrier wave signal, a demodulator configured to demodulate a returned signal by a second carrier wave signal and generate a second signal that includes an in-phase component and a quadrature component, a phase detector configured to binarize the in-phase components and the quadrature components of the first and second signals according to signal levels, and detect a phase error between the first signal and the second signal based on combinations of the binarized signal components in the first signal and the second signal, and a phase shifter configured to phase-shift the first signal, the second signal, the first carrier wave signal, or the second carrier wave signal, based on the phase error. | 12-23-2010 |
| 20110268226 | MEMORY EFFECT CANCELLER, TRANSMITTER, AND MEMORY EFFECT CANCELLING METHOD - A memory effect canceller includes a sample obtaining section that obtains a plurality of discrete-time samples of a transmission signal supplied to a power amplifier that amplifies a transmission signal, a signal generation section that generates a correction signal that is a weighted linear combination, using given weighting coefficients, of partial derivatives of a transfer function of the power amplifier, wherein the transfer function has been defined in advance with a plurality of discrete-time samples as input variables, and wherein the partial derivatives are based on the discrete-time samples obtained by the sample obtaining section at respective times, and a signal correction section that corrects an output signal of the power amplifier based on the correction signal. | 11-03-2011 |
| 20110293051 | RECEIVING DEVICE, LINEARIZER, AND DISTORTION COMPENSATION METHOD - A receiving device which receives a signal transmitted from a transmitting device by using a power amplifier, the receiving device includes a calculating unit which performs distortion compensation on a symbol included in a reception signal, a delay unit which holds a signal for a result from the distortion compensation, and the calculating unit performing the distortion compensation on a second symbol at a timing later than a first symbol based on a coefficient corresponding to an amplification characteristic of the power amplifier and on the signal for the result from the distortion compensation with respect to the first symbol held by the delay unit. | 12-01-2011 |
