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 call admission control in CDMA mobile communication system

Abstract: A call admission control scheme for a CDMA mobile communication system which can satisfy a given connection quality (blocking probability) while guaranteeing a predetermined communication quality. At each base station, a blocking probability and an outage probability of communication quality at each base station are calculated to adjust a maximum number of simultaneously connectable users at each base station according to the calculated results, and a call admission control is carried out according to the adjusted maximum number of simultaneously connectable users. A maximum number of simultaneously connectable users or an interference threshold can be determined from a first relationship between an offered traffic and a maximum number of simultaneously connectable users or an interference threshold for guaranteeing the prescribed communication quality and a second relationship between an offered traffic and a maximum number of simultaneously connectable users or an interference threshold for satisfying the prescribed blocking probability, and used for the call admission control.

Radio relay system, radio relay apparatus, and radio relay method

Abstract: A radio relay system is disclosed that is capable of preventing communication degradation in a case where radio signals are relayed using the same frequency band in a mobile communication environment. The radio relay system includes a first radio station, a second radio station, and a radio relay apparatus for relaying a radio signal that is exchanged between the first radio station and the second radio station. The radio relay apparatus includes a phase correction determining unit that determines a phase correction amount of the relayed signal based on channel information pertaining to channels established between the first radio station, the second radio station, and the radio relay apparatus, and a phase correction unit that corrects the relayed signal based on the phase correction amount determined by the phase correction determining unit.

Proactive deployment of decision mechanisms for optimal handover

Abstract: To achieve optimal selection of new access points for mobile devices (10) being located in a mobile communication environment (14), according to the present invention there is provided a method of assisting handovers for a mobile device in a mobile communication environment. It is proposed to proactively deploy a handover decision mechanism in relation to a handover and in view of the operational context of the mobile device (10). This proactively deployed handover decision mechanism is then used to determine a new access point for the mobile device (10).

Base station, user device, and method used in mobile communication system

Abstract: A base station used in a mobile communication system employing a single carrier scheme for uplink transmission is disclosed. The base station includes a scheduler configured to allocate one or more uplink resource blocks to a user device according to uplink channel conditions of the user device; and a reporting unit configured to report scheduling information indicating the allocation result to the user device. An uplink control channel of the user device is mapped to a resource block in a transmission frame including multiple resource blocks according to a hopping pattern based on the scheduling information; and the uplink control channel is mapped to a resource block according to the same hopping pattern regardless of whether the uplink control channel is associated with a user data channel.

Special Section on the Joint Call for Proposals on High Efficiency Video Coding (HEVC) Standardization

Abstract: The five papers in this special section were among those submitted in response to the joint call for proposals on high efficiency video coding (HEVC) standardization. Although at this point of development it is still unclear which specific elements the final HEVC standard will contain, the selection of the papers was made such that together they would cover most of the promising tools and technologies that seem likely to be included in the standard.