Ntt Docomo, Inc.

Ntt Mobile Communications Network, Inc.

Nippon Telegraph and Telephone Corporation

Nippon Telegraph and Telephone Public Corporation

Nit Docomo, Inc.

Ntt Decomo, Inc.

Seizo Onoe

Takehiro Nakamura

Yoshihiro Ishikawa

Etsuhiro Nakano

Akihiro Higashi

Mikio Iwamura

Hiroshi Kawakami

Takahiro Hayashi

Motoshi Tamura

Junichiro Hagiwara

Yoshiaki Ofuji

Minami Ishii

Narumi Umeda

Masafumi Usuda

Mamoru Sawahashi

Kouji Ohno

Shinji Uebayashi

Akihiro Maebara

Yukihiko Okumura

Yoshihisa Kishiyama

Motohiro Tanno

Takaaki Sato

Kazunori Obata

Kazufumi Yunoki

Masayuki Motegi

Kenichi Higuchi

Nobuhiko Miki

Yasuhiro Kato

Fumiyuki Adachi

Hidekazu Taoka

Teruo Kawamura

Koji Ohno

Masatomo Nakano

Hiroki Morikawa

Hidehiro Ando

Tomoyuki Yamada

Masafumi Hata

Daisuke Koizumi

Yoshitsugu Shimazu

Takanori Utano

Naoki Nakaminami

Yoshitaka Hiramoto

Masafumi Masuda

Mayu Yamada

Yoshiaki Nakajima

Tetsuro Imai

Masayuki Sakamoto

Masayuki Koshino

Rie Nagato

Takeshi Hattori

Isao Shimizu

Yutaka Ohto

Shinji Ueda

Masaharu Hata

Syuji Yasuda

Yoshiaki Oofuji

Takaaki Satoh

Mitsuru Murata

Shuji Yasuda

Toshinori Fujii

Yoshinobu Fukumine

Tamami Suzuki

Kimitoshi Funakawa

Hidemi Yamaguti

A communication apparatus to be used for a newer system employing an FDD scheme in an area where an older system and the newer system coexist. The communication apparatus includes a first communication unit communicating at least a downlink data channel of the newer system using a frequency band belonging to a first frequency range (3.4-3.8 GHz); and a second communication unit communicating at least an uplink control channel of the newer system using a frequency band belonging to a second frequency range (2 GHz band) lower than the first frequency range. The second frequency range is used for uplink and downlink communications in the older system.

Communication system, communication apparatus, and communication method

A base station in a mobile communications system which uses a single-carrier technique for uplink includes a classifying unit which classifies, for each of multiple user apparatuses according to a path loss between the respective user apparatus and the base station, the multiple user apparatuses into two or more groups; and a scheduler which plans allocating of uplink resources to the user apparatuses. Uplink signals of each user apparatus that have multiple frequency components lined up in equal frequency intervals are multiplexed using a distributed frequency division multiplexing technique such that they are made mutually orthogonal on a frequency axis, the scheduler plans the resource allocating such that the user apparatuses belonging to different groups utilize different group bands or different time slots, and the group bands are specified by dividing a system band into groups.

Base station and method in mobile communications system

A shared transmission/reception apparatus (OF-TRX) includes: a transmission/reception processor section (TRX-B) for a mobile communication system B configured to perform frequency conversion processing on a transmission baseband signal for the mobile communication system B outputted from a signal converter section (E/O), and to output a transmission radio frequency signal for the mobile communication system B; a power level adjuster section (VA) configured to adjust a power level of a transmission radio frequency signal for a mobile communication system A inputted from a transmission/reception processor section (TRX-A) for the mobile communication system A; a combiner section (COM) configured to generate a transmission radio frequency signal by combining the transmission radio frequency signal for the mobile communication system A outputted from the power level adjuster section (VA) and the transmission radio frequency signal for the mobile communication system B outputted from the transmission/reception processor section (TRX-B) for the mobile communication system B; and a common amplifier section (PA) configured to amplify a power level of the transmission radio frequency signal outputted from the combiner section (COM) at a predetermined amplification rate, and to output the resultant signal.

Radio base station apparatus

In this invention, a channel estimation value of data symbols of a data channel is calculated by weighting and averaging pilot symbols in a parallel time multiplexing method. Also, a channel estimation value of data symbols during each data symbol interval is calculated by dividing data symbols in a slot into a plurality of data symbol intervals, selecting pilot symbols suitable for calculation of a channel estimation value of data symbols during each data symbol interval and weighting and averaging that pilot symbols. Also, a fading frequency is detected based on an inner product value of pilot symbols. Weighting factors are changed based on the detected fading frequency. Also, a channel estimation value is calculated by weighting and averaging pilot signals using a plurality of weighting sequences. The calculated channel estimation value is used to demodulate received data. The output data with the highest quality is selected by judging reliability of these plurality of demodulated data. It is also possible to select some weighting sequences based on the result of the reliability judgment of the demodulated data for predetermined period of time. In this case, after the selection, demodulation is performed by using these selected weighting sequences only.

Channel estimation device and method, demodulation device and method, and fading frequency decision device and method

A shared AMP includes: a transmission/reception processor section (TRX-B) for a second mobile communication system configured to perform frequency conversion processing on an inputted transmission baseband signal for a mobile communication system B, and to output a transmission radio frequency signal for the second mobile communication system; a power level adjuster section (VA) configured to adjust a power level of an inputted transmission radio frequency signal for a first mobile communication system; a combiner section (COM) configured to generate a transmission radio frequency signal, by combining the transmission radio frequency signal for the first mobile communication system outputted from the power level adjuster section (VA) and the transmission radio frequency signal for the second mobile communication system outputted from the transmission/reception processor section (TRX-B) for the second mobile communication system; and a common amplifier section (PA) configured to amplify a power level of the transmission radio frequency signal outputted from the combiner section (COM) at a predetermined amplification rate, and to output the resultant signal.

A base station including a transmitting and receiving amplifier for amplifying CDMA signals exchanged with a mobile station; a radio stage connected to the transmitting and receiving amplifier for carrying out D/A conversion of a transmitted signal that undergoes baseband spreading, followed by quadrature modulation, and for carrying out quasi-coherent detection of a received signal, followed by A/D conversion; a baseband signal processor connected with the radio stage for carrying out baseband signal processing of the transmitted signal and the received signal; a transmission interface connected with the baseband signal processor for implementing interface with external channels; and a base station controller for carrying out control such as management of radio channels and establishment and release of the radio channels. The base station communicates with the external channels by mapping logical channels into physical channels. The CDMA signals are spread using a short code and a long code.

Base station apparatus of mobile communication system

A signal transmission method checks, when detecting an occurrence of a communication request, whether the communication request is a high speed communication (step S). In the case of the high speed communication, it checks whether the number of current high speed communications (m) plus one is greater than the upper limit (m) of the high speed communication (step S). If greater, it cancels the request as a call loss (S), and sets to a variable a the ratio (h) of the rate of the high speed communication to that of a low speed communication. If the communication request is the low speed communication, it sets one to the variable a (step S). It compares n plus a with n(step S), where n is the total number of all the current communications, a is the value associated with the communication request, and nis the upper limit of the number of communications acceptable in a bandwidth, all of which are expressed in terms of the number of the low speed communications. If n plus a is greater than n, the communication request is canceled as a call loss (S). Otherwise, the total number of the current high speed communications (m) and the total number of all the current communications (n) expressed in terms of the number of the low speed communications are updated, and a channel is assigned to the communication request (step S).

Signal transmission method and base station in mobile communication

A channel estimation value of data symbols of a data channel is calculated by weighting and averaging pilot symbols in a parallel time multiplexing method. Also, a channel estimation value of data symbols during each data symbol interval is calculated by dividing data symbols in a slot into a plurality of data symbol intervals, selecting pilot symbols suitable for calculation of a channel estimation value of data symbols during each data symbol interval and weighting and averaging that pilot symbols. Also, a fading frequency is detected based on an inner product value of pilot symbols. Weighting factors are changed based on the detected fading frequency. Also, a channel estimation value is calculated by weighting and averaging pilot signals using a plurality of weighting sequences. The calculated channel estimation value is used to demodulate received data.

A mobile communication system includes an extension transmission/reception server configured to transmit/receive user data transmitted/received between mobile stations to/from a base station by using an extension transmission/reception transmitting/receiving the data within a radio access network, and the base station configured to transmit/receive the user data to/from the extension transmission/reception server.

Mobile communication system, extension transmission/reception server, extension transmission/reception controller, base station, radio network controller, mobile station and communication method

A base station captures phase difference information between a long period spreading code of a common control channel of the base station and a long period spreading code of a common control channel of a neighboring base station of the base station from a mobile station. The base station transmits the phase difference information to a mobile station. The mobile station carries out cell search in accordance with the received phase difference information.

Neighboring base station information update method, information management method for cell search in mobile communications system, cell search method of mobile station, mobile communications system, mobile station, base station and control station

A CDMA apparatus including a propagation path variation estimator for estimating propagation path variations between respective prior transmit power control sections and a current transmit power control section to obtain propagation path variation estimation values, wherein each of the propagation path variation estimation values is obtained by estimating a propagation path variation between a different corresponding prior transmit power control section and the current transmit power control section; propagation path variation correction part for generating a plurality of corrected products, each corrected product obtained by multiplying at least one of vector, amplitude and/or power of a received signal of the different corresponding prior transmit power control section by said propagation path variation estimation value obtained by estimating the propagation path variation between the different corresponding prior transmit power control section and the current transmit power control section; and averaging part for averaging the plurality of corrected products.

Channel identifier assigning method and mobile communications system

Resource measurement deviceacquires a measured value x of the resource use condition in transmitting/receiving sectionin respect of the wireless resource that is the subject of monitoring. Also, correction value calculation devicecalculates a correction value in accordance with the number of packet users at transmitting/receiving sectionand adjustment deviceadjusts the call acceptance threshold value xusing the correction value, so as to obtain a corrected threshold value x'. Comparatorthen compares the measured value of the resource use condition x and the corrected threshold value x&#x2032; and outputs the comparison result to call acceptance control device. If x&#x2267;x&#x2032;, call acceptance control devicerestricts acceptance of new calls. Thus, the call acceptance control method, mobile communication system and base station device whereby deterioration of communication quality is suppressed irrespective of the switching system are provided in mobile communication in which multiple access is performed with shared wireless resources.

Call acceptance control method, mobile communication system and base station device

A signal transmission method and apparatus over a forward traffic channel in cellular mobile communications that can simultaneously perform one or more high speed communications whose transmission rates are higher than or equal to a predetermined rate, and one or more low speed communications whose transmission rates are lower than the predetermined rate between a plurality of mobile stations and a base station.

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Yokohama, Japan

Seizo Onoe