Patent application number | Description | Published |
20100303163 | DEMODULATING CIRCUIT, DEMODULATING METHOD, AND RECEIVING SYSTEM - A demodulating circuit includes: a fast Fourier transform circuit which fast Fourier transforms a received signal and outputs a plurality of carrier signals; an output selecting circuit which selects at least two signals from the plurality of carrier signals, the at least two signals including a first signal modulated in accordance with a first modulation method and a second signal modulated in accordance with a second modulation method; an inverse fast Fourier transform circuit which inverse Fourier transforms transmission path characteristic values including a first transmission path characteristic value obtained based on the first signal and a second transmission path characteristic value obtained based on the second signal; and an FFT window control circuit which controls a position of an FFT window based on the inverse Fourier transformed transmission path characteristic values. | 12-02-2010 |
20110004806 | DATA RECEIVING CIRCUIT AND DATA PROCESSING METHOD - A data receiving circuit includes: a first de-interleave circuit configured to de-interleave first data which is demodulated and is soft-decision-processed; a second de-interleave circuit configured to de-interleave second data which is demodulated and is soft-decision-processed; a memory configured to be shared by the first de-interleave circuit and the second de-interleave circuit and store respective hard decision information and respective soft decision information of the first data and the second data; and a memory control circuit configured to vary a first through fourth number of bits stored in the memory, the first number corresponding to the hard decision information of the first data, the second number corresponding to the soft decision information of the first data, the third number corresponding to the hard decision information of the second data, the fourth number corresponding to the soft decision information of the second data. | 01-06-2011 |
20120300883 | DEMODULATION CIRCUIT, DEMODULATION METHOD AND RECEIVING APPARATUS - A demodulation circuit includes a hard decision process unit and a soft decision process unit. The hard decision process unit is configured to perform a hard decision process using a demodulated signal, and the demodulated signal is a demodulated received signal. The soft decision process unit is configured to determine a range of assignment with respect to a transitioning part in the demodulated signal, calculate a likelihood value of a bit, and perform a soft decision process. | 11-29-2012 |
20120307944 | RECEIVING APPARATUS AND RECEIVING METHOD - A receiving apparatus includes a symbol timing detection unit, a Fourier transform unit, a first symbol timing correction unit, and an interpolation synthesis unit. The symbol timing detection unit is configured to detect a Fourier transform start position from a received transmitting signal of a symbol unit, the Fourier transform unit is configured to perform a Fourier transform using the detected Fourier transform start position. The first symbol timing correction unit is configured to calculate and correct an amount of change between the Fourier transform start position of a reference symbol and the detected Fourier transform start position, and the interpolation synthesis unit is configured to perform an interpolation synthesis of a plurality of delay profiles corresponding to a plurality of symbols including the reference symbol and a symbol in which the amount of change is corrected. | 12-06-2012 |
20130301759 | RECEIVING DEVICE AND RECEIVING METHOD - A receiving device for receiving OFDM signals in which arrangement of pilot signals changes with symbol time, includes: an inverse Fourier transform unit configured to calculate an impulse response by performing an inverse Fourier transform on pilot signals included in a received signal; a first Doppler frequency estimation unit configured to estimate a first Doppler frequency from a phase rotation amount at peak positions between impulse responses of pilot signals of different subcarriers of the impulse responses; a second Doppler frequency estimation unit configured to estimate a second Doppler frequency from a phase rotation amount between impulse responses of pilot signals of the same subcarrier of the impulse responses; and a Doppler frequency selection unit configured to select one of the first and the second Doppler frequency estimated by the first and the second Doppler frequency estimation unit so as to reduce influence of a multipath. | 11-14-2013 |
20140270022 | DATA SIGNAL CORRECTION CIRCUIT, RECEIVER, AND DATA SIGNAL CORRECTION METHOD - A data signal correction circuit includes a channel characteristic calculator unit configured to calculate a channel characteristic estimate value of a received data signal on the basis of a pilot signal, a path detector unit configured to determine a delay quantity of multipath propagation of the received data signal on the basis of the calculated channel characteristic estimate value, and an adaptive filter configured to receive the delay quantity and the channel characteristic estimate value as input items, adjust an input interval of the channel characteristic estimate value along a carrier frequency axis in accordance with the delay quantity, and perform adaptive equalization on the channel characteristic estimate value inputted to the adaptive filter at the adjusted input interval. | 09-18-2014 |
20140294128 | RECEIVER AND SYNCHRONIZATION CORRECTING METHOD - A receiver includes a transformation part configured to convert a time domain received signal to a frequency domain signal, a known signal extraction part configured to extract a known signal from the frequency domain signal, an estimation part configured to estimate a channel characteristic based upon the extracted known signal, a time direction extraction part configured to extract channel characteristic values of a particular carrier in a time direction from the estimated channel characteristic, a power spectrum acquiring part configured to acquire a power spectrum from the channel characteristic values extracted in the time direction, an error calculation part configured to calculate a carrier frequency error from the power spectrum, and a carrier correction part configured to correct for a carrier frequency of the received signal based upon the carrier frequency error. | 10-02-2014 |
20140294130 | RECEIVER AND SIGNAL PROCESSING METHOD - A receiver includes a detector to detect an interfered-with carrier from a received and demodulated signal, a fast Fourier transform computation part to perform fast Fourier transform to convert a time domain signal to a frequency domain signal and adjust an output power level of a desired carrier wave contained in the frequency domain signal based upon the detected interfered-with carrier, and a channel estimation part to estimate a channel characteristic based upon a non-interfered-with pilot signal that is not subject to influence of the interfered-with carrier and an interpolation value interpolated based upon the non-interfered-with pilot signal, the non-interfered-with pilot signal being obtained by removing, based upon the interfered-with carrier, an interfered-with pilot signal that is subject to the influence of the interfered-with carrier and an interpolation value interpolated based upon the interfered-with pilot signal. | 10-02-2014 |
20140301506 | DATA PROCESSING METHOD - A data receiving circuit includes: a first de-interleave circuit configured to de-interleave first data which is demodulated and is soft-decision-processed; a second de-interleave circuit configured to de-interleave second data which is demodulated and is soft-decision-processed; a memory configured to be shared by the first de-interleave circuit and the second de-interleave circuit and store respective hard decision information and respective soft decision information of the first data and the second data; and a memory control circuit configured to vary a first through fourth number of bits stored in the memory, the first number corresponding to the hard decision information of the first data, the second number corresponding to the soft decision information of the first data, the third number corresponding to the hard decision information of the second data, the fourth number corresponding to the soft decision information of the second data. | 10-09-2014 |
Patent application number | Description | Published |
20090010370 | Digital Broadcast Demodulator and Digital Broadcast Demodulation Method for Suppressing Degradation of Reception Characteristics - A digital broadcast demodulator receives a tuner signal output from a tuner and carries out demodulation processing on the tuner signal by using an internal clock signal that is synchronized with a reference signal. The digital broadcast demodulator has an internal clock-signal generator and an internal clock frequency controller. The internal clock-signal generator generates the internal clock signal, and the internal clock frequency controller controls a frequency of the internal clock signal in accordance with a reception channel. | 01-08-2009 |
20090097576 | OFDM RECEIVER APPARATUS HAVING A PLURALITY OF RECEIVER CIRCUITS AND OFDM RECEIVING METHOD - A receiver circuit in each branch has an FFT unit that performs Fourier transform on OFDM signals. A slave branch FFT window control unit determines whether an undesired wave is a preceding wave or a delay wave, and notifies a master branch of the result. In response to the notification from the slave branch, a master branch FFT window control unit controls a position of an FFT window that indicates a time range in which Fourier transform is performed on OFDM signals. | 04-16-2009 |
20090097577 | OFDM RECEIVING APPARATUS HAVING PLURALITY OF OFDM BRANCHES - An OFDM signal is demodulated to generate a frequency domain signal in each of a plurality of branches. A diversity combining unit combines the demodulated signals respectively obtained in each of the branches. A clock recovery unit recovers the clock for the OFDM signal. A guard correlation unit detects the phase error of the OFDM signal. A decision unit identifies a branch having high reliability. A clock error correction unit generates a correction instruction, in accordance with the average value of the phase errors in the branch having high reliability. The clock recovery unit in each of the branches respectively corrects the error of the clock in accordance with the correction instruction. | 04-16-2009 |
20090097593 | BROADCAST DEMODULATION DEVICE - In a demodulation device with a plurality of branches, the receiving quality of each branch and signal quality after composing signals from the plurality of branches is inspected. If the signal quality is good, the operation of a branch whose receiving quality of each branch is the worst is stopped. When activating a stopped branch, the synchronous detection information of an already operated branch is applied to a branch to be newly activated and time needed for a newly activated branch to become synchronous is reduced. | 04-16-2009 |
20090285086 | OFDM Receiver and OFDM Receiving Method - An FFT unit generates a frequency domain signal by converting an OFDM signal using Fourier transform. A delay amount calculation unit generates a delay profile of the OFDM signal. The control determination unit detects a main wave and an interference wave using the delay profile. When the time difference between the main wave and a preceding wave is larger than a guard interval of the OFDM signal, an FFT window control unit sets the start position of the FFT window at a position shifted forward from the symbol start position of the main wave by an amount corresponding to the guard interval. | 11-19-2009 |
20090285318 | Digital Broadcast Receiver and Digital Broadcast Receiving Apparatus - An FFT unit generates a frequency-domain signal for one-segment broadcasting and a frequency-domain signal for full-segment broadcasting. Under a good reception environment, the frequency-domain signal for the full-segment broadcasting is extracted by a switching control unit and the transmitted data for the full-segment broadcasting are recovered. When the reception environment deteriorates, both the one-segment broadcasting and the full-segment broadcasting are temporary demodulated. After a delay time due to the demodulation process has passed, a reception mode is switched from the full-segment broadcasting to the one-segment broadcasting. | 11-19-2009 |