1
Yuji Aburakawa, Hirohito Suda, Yasushi Yamao: Radio base station system and central control station with unified transmission format. NTT Docomo, Oblon Spivak McClelland Maier & Neustadt P C, July 4, 2006: US07072586 (102 worldwide citation)

A central control station, which controls radio base stations connected thereto via radio links and optical fiber links, includes a demultiplexing unit which demultiplexes signals supplied from an upper-level station, signal conversion units which convert the respective demultiplexed signals into co ...


2
Yoshiaki Tarusawa, Shigeki Saito, Yasushi Yamao, Toshio Nojima: Frequency synthesizer having compensation for nonlinearities. Nippon Telegraph and Telephone Corporation, Cushman Darby & Cushman, December 25, 1990: US04980652 (82 worldwide citation)

In a phase locked loop frequency synthesizer, the frequency of a VCO is switched by changing the division ratio of a variable ratio frequency divider in the feedback path of the loop. At the time of switching, a prepositioning voltage is applied to the VCO to realize fast frequency switching. To cor ...


3
Yasunori Suzuki, Shinji Mizuta, Tetsuo Hirota, Yasushi Yamao: High-efficiency linear power amplifier. NTT BoCoMo, Oblon Spivak McClelland Maier & Neustadt P C, May 9, 2006: US07042283 (73 worldwide citation)

A transmission signal and a pilot signal are predistorted by a digital predistorter 13 by use of a power-series model, and the predistorted output is converted by a digital-analog converter 14 to an analog signal. The analog signal is up converted by a frequency converter 15 to an RF-band signal, wh ...


4
Kouji Chiba, Toshio Nojima, Yasushi Yamao, Shigeru Tomisato, Tadao Takami: Linear transmitter. Nippon Telegraph & Telephone Corporation, Cushman Darby & Cushman, October 5, 1993: US05251330 (73 worldwide citation)

This invention relates to a linear transmitter which controls the bias voltage of either the drain electrode or collector electrode of an amplifier for radio frequency based on the envelope of the modulated signal, and is characterized in that it controls the bias voltage of the radio frequency ampl ...


5
Lan Chen, Narumi Umeda, Yasushi Yamao: Packet transmission method, base station and mobile station. NTT Docomo, Oblon Spivak McClelland Maier & Neustadt P C, October 28, 2008: US07443816 (38 worldwide citation)

A packet transmission method in which packets are transmitted between a base station and a mobile station communicating with the base station includes the steps of: recognizing the size of each of the packets to be transmitted; determining a transmission rate for each packet in accordance with the r ...


6
Shigeki Saito, Yasushi Yamao: Phase likelihood comparison diversity receiver. Nippon Telegraph and Telephone Corporation, Cushman Darby & Cushman, April 13, 1993: US05203023 (36 worldwide citation)

In the diversity receiver which switches between receiver branches to receive phase modulated signals, this invention can achieve a diversity effect with a circuit of simple construction which by switching between receiver branches based on relative modulation phase error, and can attain diversity e ...


7
Yasushi Yamao: Antenna selection diversity reception system. Nippon Telegraph & Telephone, Armstong Westerman Hattori McLeland & Naughton, April 13, 1993: US05203024 (27 worldwide citation)

An antenna selection diversity receiver system for TDM signals that switches antennas for every assigned time slot so that the best receive signal quality is obtained in the assigned time slot according to the prediction made by using the signal quality just before the assigned time slot. The predic ...


8
Hijin Sato, Narumi Umeda, Yasushi Yamao: Rendering multicast service with sufficient reception quality to wireless terminals. NTT Docomo, Oblon Spivak McClelland Maier & Neustadt P C, May 17, 2005: US06895216 (24 worldwide citation)

The method of invention provides a multicast service from an information delivery apparatus to wireless terminals through wireless routes. The method includes the step of transmitting, from the information delivery apparatus, a plurality of sets of multicast information, wherein these sets are ident ...


9
Shogo Ito, Yasushi Yamao, Shinzo Ohkubo: Time diversity communications system. NTT Mobile Communications Network, Cushman Darby & Cushman IP Group of Pillsbury Madison & Sutro, August 11, 1998: US05794124 (24 worldwide citation)

A system wherein time diversity reception is performed for each error-corrected or error-detected code word without distinguishing between the address signal and the message signal, the code words being the units which make up the address and message signals. A received signal comprising correctly d ...


10
Ichiro Okajima, Yasushi Yamao: Method and device for communicating via an ad-hoc wireless network. NTT Docomo, Oblon Spivak McClelland Maier & Neustadt P C, May 29, 2007: US07224954 (22 worldwide citation)

A communication method used when a mobile station receives a signal from a base station in a mobile communication system is provided. The method includes the steps of: deciding one or a plurality of mobile stations which can communicate with the mobile station via a predetermined wireless network an ...