Patent application number | Description | Published |
20090201085 | POWER AMPLIFYING APPARATUS AND MOBILE COMMUNICATION TERMINAL - A power amplifying apparatus includes an input terminal configured to receive an input signal, a first power amplifier biased for class A or class AB operation which is configured to amplify the input signal, an output terminal connected to an output of the first power amplifier, a second power amplifier biased for class C operation which is configured to receive and amplify a part of the input signal, and a switch connected between an output of the second power amplifier and the output terminal. | 08-13-2009 |
20100120475 | WIRELESS COMMUNICATION APPARATUS AND POWER-SUPPLY APPARATUS - A wireless communication apparatus includes a power-supply apparatus configured to supply electric power to a load that is intermittently operated by using a battery as a power supply; and a control unit configured to control the power-supply apparatus, wherein the power-supply apparatus includes a capacitor; a switching unit capable of selectively forming a first path through which charging is performed from the battery to the capacitor and a second path through which the battery is connected in series with the capacitor, and wherein the control unit controls the switching unit so that the first path is formed during a period in which the load is idle and the second path is formed during a period in which the load is not idle, and thereby supplies the voltage of the sum of the battery voltage and the charged voltage of the capacitor in a non-idle period. | 05-13-2010 |
20110310990 | POWER AMPLIFICATION APPARATUS, OFDM MODULATION APPARATUS, WIRELESS TRANSMISSION APPARATUS, AND DISTORTION REDUCTION METHOD FOR POWER AMPLIFICATION APPARATUS - A power amplification apparatus that performs an inverse fast Fourier transformation on data allocated to a plurality of sub-carriers, converts time-domain data output in parallel from the inverse fast Fourier transformation into a time-domain analog signal, performs a power amplification on the time-domain analog signal, wherein a saturation output level of the power amplification is adjustable in accordance with a switching signal. The power amplification apparatus also compares an amplitude of a signal in each time slot of the time-domain analog signal with a predetermined threshold and switches the saturation output level of the power amplification based on an output of the comparing. | 12-22-2011 |
20140056373 | COMMUNICATION SYSTEM, COMMUNICATION DEVICE, AND RECEPTION DEVICE - A communication system including a transmission device having a plurality of transmission antennas that transmit a plurality of signals under a multiple input multiple output (MIMO) scheme; and a reception device having a plurality of reception antennas that receive the plurality of signals under the MIMO scheme. The transmission device is configured to add a preamble signal to a transmission signal transmitted to the reception device at an earliest timing among transmission signals that are modulated under an orthogonal frequency division multiplexing (OFDM) scheme, the transmission signals being output from the transmission antennas. The transmission device does not add the preamble signal to the transmission signals other than the transmission signal transmitted at the earliest timing. | 02-27-2014 |
20140140195 | COMMUNICATION METHOD AND TRANSMISSION APPARATUS - An electronic device that performs an inverse fast Fourier transform (IFFT) on N (N is an integer equal to or larger than 2) orthogonal frequency-division multiplexed (OFDM) transmission signals; performs a fast Fourier transform (FFT) on the N transmission signals which have been subjected to the IFFT; detects phases of the N transmission signals which have been subjected to the FFT; detects relative delay amounts of the N transmission signals based on the detected phases of the N transmission signals; and adjusts a timing at which at least one of the N transmission signals is subjected to the inverse fast Fourier transform based on the detected relative delay amounts. | 05-22-2014 |
20140140449 | COMMUNICATION METHOD AND RECEPTION APPARATUS - An electronic device that digitizes a baseband signal obtained from a received high-frequency signal; specifies a position of a preamble included in the digitalized signal; calculates a square of the preamble; specifies a peak from a value obtained by the square of the preamble; performs a fast Fourier transform (FFT) on the baseband signal using a position of the peak as a start of an FFT window; extracts phases of a plurality of frequency components for phase measurement from the baseband signal which has been subjected to the FFT; obtains a phase difference of the plurality of phases; and obtains a phase correction value of a reception signal using the phase difference and a phase reference. | 05-22-2014 |
20140254699 | MIMO COMMUNICATION METHOD, MIMO TRANSMITTING DEVICE, AND MIMO RECEIVING DEVICE - A first digital signal sequence including I and Q digital signal sequences is obtained, the first digital signal sequence being obtained by multiplying each bit of an I-sequence and a Q-sequence in a digital signal sequence system by a first code among codes constituting n-th order (n is an integer) orthogonal codes. A second digital signal sequence is obtained by multiplying I and Q digital signal sequences by a first coefficient greater than 1, the I and Q digital signal sequences being obtained by multiplying each of the bits in the I-sequence and the Q-sequence in the digital signal sequence system by a first code among codes constituting 2n-th order orthogonal codes. The first digital signal sequence and the second digital signal sequence are added on a bit-by-bit basis to create one digital signal sequence, and the one digital signal sequence is transmitted from a single antenna. | 09-11-2014 |
20150139345 | MIMO COMMUNICATION METHOD - A method of achieving diversity in a multiple-input-multiple-output (MIMO) communication system. The MIMO communication system has a lower number of receiving antennas compared to the number of transmitting antennas. In the MIMO communication system, selection diversity is achieved by using a switch that selectively chooses a receiver antenna based on a signal to noise ratio of the signal captured by the receiving antenna. Alternatively, the signals that are received by the respective receiving antennas are combined in order to achieve combination diversity. | 05-21-2015 |