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Institution

NTT DoCoMo

About: NTT DoCoMo is a based out in . It is known for research contribution in the topics: Base station & Mobile station. The organization has 4032 authors who have published 8655 publications receiving 160533 citations.


Papers
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Patent
21 May 2008
TL;DR: In this paper, the reference signal is generated by multiplying a first sequence formed by a non-orthogonal code sequence which is different at least between an adjacent cell and an own cell, by a second sequence.
Abstract: A base station apparatus for use in a mobile communication system includes: a unit configured to generate a reference signal; a unit configured to generate a transmission symbol including the reference signal; a unit configured to transmit the transmission symbol for each sector; and a unit configured to monitor a radio propagation state. The reference signal is generated by multiplying a first sequence formed by a non-orthogonal code sequence which is different at least between an adjacent cell and an own cell, by a second sequence. Whether to form the second sequence by using an orthogonal code sequence which is different among sectors or by using a non-orthogonal code sequence is determined according to the radio propagation state.

48 citations

Patent
02 May 2008
TL;DR: In this paper, a circulator extracts a transmission signal sent from a transmitter to antenna via the circulator and a duplexer, reflected by an antenna, and returned via the duplexe to the transmitter side.
Abstract: A circulator extracts a transmission signal sent from a transmitter to antenna via the circulator and a duplexer, reflected by an antenna, and returned via the duplexer to the transmitter side The amplitude and phase of the extracted signal are adjusted by an amplitude-and-phase adjuster to generate an offset signal having the same amplitude and the opposite phase with respect to a leaking transmission signal included in a signal output from a third terminal of the duplexer when combined by a combiner The offset signal is combined in the combiner with the leaking transmission signal included in the signal output from the third terminal of the duplexer to suppress the leaking transmission signal

48 citations

Proceedings ArticleDOI
24 Oct 2005
TL;DR: In this paper, a driver identification method is proposed based on the driving behavior signals that are observed while the driver is following another vehicle, such as the use of the accelerator pedal, brake pedal, vehicle velocity, and distance from the vehicle in front.
Abstract: In this paper, we propose a driver identification method that is based on the driving behavior signals that are observed while the driver is following another vehicle. Driving behavior signals, such as the use of the accelerator pedal, brake pedal, vehicle velocity, and distance from the vehicle in front, are measured using a driving simulator. We compared the identification rate obtained using different identification models and different features. As a result, we found the nonparametric models is better than the parametric models. Also, the driver's operation signals were found to be better than road environment signals and car behavior signals. The identification rate for thirty driver using actual vehicle driving in a city area was 73%.

48 citations

Patent
Ulas C. Kozat1
13 Mar 2013
TL;DR: In this article, a method and apparatus for low delay access to key-value-based storage systems is presented, where an erasure coding to apply to K portions of data as a function of delay performance of the storage system is discussed.
Abstract: A method and apparatus is disclosed herein for low delay access to key-value based storage systems. In one embodiment, the method for putting data into a key-value store comprises selecting an erasure coding to apply to K portions of data as a function of delay performance of the key-value based storage system including determining a number of parity blocks to satisfy one or both of a delay target of putting the object into the key-value store and a delay target of subsequent read requests based on an offline performance simulation of delay performance; applying the erasure coding to the K portions to create N blocks of data; and sending the N write requests to write blocks of data to the storage system, where each block is assigned a unique key in the key-value store.

48 citations

Proceedings ArticleDOI
08 Jun 2003
TL;DR: In this paper, a new feed-forward amplifier configuration that uses a Doherty amplifier with Class-F operation as the main amplifier is proposed, which can effectively reduce the power consumption of the power amplifiers for cellular base stations.
Abstract: A new feed-forward amplifier configuration is proposed that uses a Doherty amplifier with Class-F operation as the main amplifier. Due to the new configuration, the enhanced main amplifier operates well with less output back-off and achieves high efficiency under Class-F operation compared with Class-B amplifier (non Doherty amplifier). A 2-GHz band 1-W class feed-forward amplifier is investigated. A back-off improvement of 3 dB is experimentally achieved compared with a conventional feed-forward amplifier for the same intermodulation distortion level. The efficiency of the main amplifier is also improved from 33% to 52% when third-order intermodulation distortion of feed-forward amplifier is - 50 dB. The proposed technique can effectively reduce the power consumption of the power amplifiers for cellular base stations.

48 citations


Authors

Showing all 4032 results

NameH-indexPapersCitations
Amit P. Sheth10175342655
Harald Haas8575034927
Giuseppe Caire8282540344
Craig Gentry7522239327
Raj Jain6442430018
Karl Aberer6355417392
Fumiyuki Adachi54101015344
Ismail Guvenc5245113893
Frank Piessens5239110381
Wolfgang Kellerer495029383
Yoshihisa Kishiyama4837911831
Ravi Jain481607467
Josef A. Nossek4862310377
Tadao Nagatsuma4743011117
Christian Bettstetter4620411051
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202164
2020143
2019240
2018269
2017193
2016173