Patent application number | Description | Published |
20080198799 | Radio Communication System - In a wireless communication system using the contention method, collisions between transmission signals sent from terminals to a base station are avoided, and a communication area is flexibly formed while suppressing unnecessary radiation of the communication area. The base station includes antennas disposed such that wireless zones cover mutually different areas, wireless units connected to the antennas in one-to-one correspondence, and for, via the respective antennas, receiving wireless signals from the terminal stations in the wireless zones and transmitting wireless signals to the terminal stations in the wireless zones, a data processing unit for processing the wireless signals received by the plurality of wireless units and generate data to be transmitted to the terminal stations, and a communication control unit for controlling the wireless units so as to, during a slot other than a transmission request slot, form one communication area combining the wireless zones of all of the antennas, and during the transmission request slot, form mutually independent communication areas less than or equal in number to the antennas. | 08-21-2008 |
20080198835 | Wireless Transmission System And Wireless Transmission Method And Wireless Station For Use Therein - The present invention provides a wireless station capable of increasing the probability that a path diversity effect can be obtained in a case where a plurality of wireless stations transmit packets using a modulation/demodulation scheme with an anti-multipath property. A delay amount determining section ( | 08-21-2008 |
20090036052 | WIRELESS STATION, WIRELESS TRANSMISSION METHOD FOR THE WIRELESS STATION, AND WIRELESS TRANSMISSION SYSTEM USING THE WIRELESS STATION - A wireless station according to the present invention is a wireless station used as one of a plurality of relay stations forming transmission paths, respectively, different from each other, in a wireless transmission system for transmitting a packet from a transmitting station to a receiving station through the plurality of relay stations, and the wireless station comprises: a reception section for receiving a packet transmitted from the transmitting station, and receiving a packet which is transmitted, based on the packet transmitted from the transmitting station, from a relay station other than the one of the plurality of relay stations, and is transmitted before the one of the plurality of relay stations performs transmission, by using a transmission parameter for obtaining a path diversity effect in the wireless transmission system; a transmission parameter estimation section for estimating the transmission parameter used by the relay station other than the one of the plurality of relay stations, based on the packet received by the reception section from the relay station other than the one of the plurality of relay stations; a transmission parameter selection section for selecting the transmission parameter other than the transmission parameter which is used by the relay station other than the one of the plurality of relay stations, and is estimated by the transmission parameter estimation section; and a transmission section for transmitting, to the receiving station, the packet received by the reception section from the transmitting station, by using the transmission parameter selected by the transmission parameter selection section. | 02-05-2009 |
20090097584 | WIRELESS TRANSMISSION SYSTEM, WIRELESS TRANSMISSION METHOD, AND WIRELESS STATION AND TRANSMITTING STATION USED THEREIN - The present invention provides a wireless transmission system capable of exerting a maximum path diversity effect by using combinations formed by a plurality of symbol waveforms even when a maximum number of effective branches is limited to a small number. A transmission timing controlling section ( | 04-16-2009 |
20100239039 | WIRELESS TRANSMISSION SYSTEM, AND WIRELESS STATION AND METHOD USED FOR SAME - A wireless transmission system capable of performing multi-station simultaneous transmission of data by wireless is provided. The wireless transmission system includes a plurality of wireless stations for transmitting and receiving data. Transmitter-side wireless stations, a multipath channel, and receiver-side wireless stations constitute a system for path diversity. At least one wireless station among the wireless stations determines, depending on a response packet with respective to a multi-station simultaneous transmission request packet transmitted by itself or other stations, a plurality of delay amounts from a reference timing during multi-station simultaneous transmission in the wireless transmission system, and a plurality of symbol waveforms that are a basis for a modulated waveform. A difference between each delay amount is set to be larger than or equal to a predetermined delay resolution for each symbol waveform, and a difference between maximum and minimum values of the delay amounts is set to be smaller than or equal to a predetermined maximum delay. | 09-23-2010 |
20120002707 | PLL FREQUENCY SYNTHESIZER - A PLL frequency synthesizer includes: a phase comparator configured to detect a phase difference between a reference clock signal and an output signal of the PLL frequency synthesizer; a loop filter configured to output a control value composed of a total of an integer value and a decimal value; a first controller configured to output a first control signal corresponding to the integer value in synchronization with a first clock; a second controller configured to output a second control signal representing the decimal value as a mean value in synchronization with a second clock, and when the PLL frequency synthesizer is in a locked state, to limit a range of values which the second control signal can have to a range in the locked state; and a digital controlled oscillator configured to oscillate at a frequency based on a combination of frequency control by the first and second control signals. | 01-05-2012 |
20120119800 | PLL FREQUENCY SYNTHESIZER - In a digital PLL frequency synthesizer, after lock detection, first oscillating signal phase information is switched to second oscillating signal phase information by an estimation section based on previous oscillating signal phase information and a phase difference. As a result, the first oscillating signal phase information which has a risk of an error in the normal state (locked state) is not used. In addition, a conventional high-speed latch circuit for reclocking is not required. As a result, power consumption can be reduced, compared to the conventional art, while reducing or avoiding a degradation in phase-noise characteristics. | 05-17-2012 |
20120119839 | PLL FREQUENCY SYNTHESIZER - Disclosed is a PLL frequency synthesizer the phase noise characteristics of which are improved. To achieve this, in an ADPLL frequency synthesizer ( | 05-17-2012 |
20120139654 | FREQUENCY SYNTHESIZER - A frequency synthesizer includes a control circuit configured to generate a digital control signal; and a digitally controlled oscillator of which oscillation frequency changes according to the generated digital control signal. The control circuit includes an operational circuit configured to divide an integer portion of a numerical value representing a phase difference between a reference signal and an oscillation frequency signal of the digitally controlled oscillator into high-order bits and low-order bits including a redundant bit as an MSB, and two encoders configured to encode the high-order bits and the low-order bits to generate control signals. The digitally controlled oscillator includes two capacitive element groups having capacitance values controlled by the control signals. The oscillation frequency of the digitally controlled oscillator changes according to a total capacitance value of the two capacitive element groups. | 06-07-2012 |