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.

Method and apparatus for arithmetic coding and termination

Abstract: Methods and apparatuses for performing arithmetic encoding and/or decoding are disclosed. In one embodiment, an arithmetic decoder comprises a sequencer to generate a context identifier for an event of an event sequence, a probability estimator to determine a value for a LPS and a probability estimate for the LPS, and a decoding engine that includes a range register to assign a value to a range for the LPS. The value is based on the probability estimate, a value stored in the range register and the context identifier to a range for the LPS if the context identifier is not equal to an index and the value is not based on the value stored in range register if the context identifier is equal to the index. The decoding engine further determines a value of a binary event based on the value of the range for the LPS and bits from an information sequence.

Mobility enhancements for heterogeneous networks through interference coordination

Abstract: Mobility performance of heterogeneous networks (HetNets) is studied in terms of handover failure and ping-pong rates of user equipments (UEs) in co-channel deployment of macro- and pico- cells. Simulation assumptions and parameters of a related study item in 3GPP are used to investigate the impact of various handover-related parameters on mobility performance. Then, a mobility-based inter-cell interference coordination (MB-ICIC) technique is proposed, in which picocells configure almost blank subframes in order to protect high-mobility macrocell UEs. Through extensive simulations, MB-ICIC is shown to provide handover performance gains for both low-mobility and high-mobility UEs. In addition, we show through simulations that performance of the mobility state estimation technique in 3GPP standard specifications is good enough for supporting the proposed MB-ICIC in HetNets.

Millimeter-Wave Wireless Communication Systems: Theory and Applications

Abstract: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers.

Mobile communication system and mobile communication method

Abstract: An estimator 120 of a mobile station 100 a of the present invention estimates traveling speed information which is a value variable with either a traveling speed of the mobile station or a variation in the traveling speed. A comparison unit 130 or a comparison unit 320 compares the traveling speed information estimated by the estimator with a threshold defined as a value of traveling speed information for achieving a desired level of communication quality which varies depending on the traveling speed. A selector 150 or a selector 340 selects an applicable frequency band in response to a result of comparison.

Data communication regulating method of fixed rate system user, data communication regulation controller and portable terminal

Abstract: PROBLEM TO BE SOLVED: To provide a fixed rate system user communication regulating method for finitely applying communication regulation to a specific user, and for applying firm communication regulation which can not be easily released at a portable terminal side at the time of defining data communication such as packet communication as an object. SOLUTION: This data communication regulating method comprises a process for monitoring the data communication status of a fixed rate system user, and for judging whether or not the number of times of request or communication quantity within a predetermined period exceed a predetermined threshold, a process for setting the fixed rate system user as the object of communication regulation when it is judged that they exceed the predetermined threshold and a process for transmitting a communication regulation signal including the information of a communication regulation time to the portable terminal of the fixed rate system user when access is performed again from the fixed rate system user set as the object of communication regulation. The data communication of the portable terminal of the fixed rate system user is put in an inhibited status across the communication regulation time. COPYRIGHT: (C)2006,JPO&NCIPI