Ntt Mobile Communications Network, Inc.

Ntt Docomo, Inc.

Matsushita Communication Industrial Co., Ltd.

Nit Docomo, Inc.

Ntt Communications Networks, Inc.

Fujitsu Corporation

Akihiro Higashi

Koji Ohno

Seizo Onoe

Etsuhiro Nakano

Takehiro Nakamura

Hiroshi Kawakami

Motoshi Tamura

Junichiro Hagiwara

Hiroki Morikawa

Masatomo Nakano

Mamoru Sawahashi

Fumiyuki Adachi

Narumi Umeda

Shinsuke Ogawa

Hirofumi Takagi

Kenichi Higuchi

Yukihiko Okumura

Yoshihiro Ishikawa

Kazufumi Yunoki

Tadao Takami

Hidetoshi Ishikawa

Tomohiro Dohi

Taku Nagase

Akira Kaiyama

Kiyohito Nagata

Xuan Fu

Seiji Hagiwara

Jianrong Wu

Hisashi Nakagomi

Toyota Nishi

Tadashi Matsumoto

Roland Go

Seizou Onoe

Akira Hiroike

Ryusuke Kaneda

Kanehiro Imai

Yukio Yamauchi

Fumio Kikuchi

Shinsuke B-109 Lions Mansion Shin-Yokohama Ogawa

Fumio Ntt Docomo Inc Ip Department Sanno Park Tower Kikuchi

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 control for varying a maximum transmission power of a transmitter according to a propagation loss or a distance between the transmitter and a receiver is made possible to reduce deterioration of a user capacity to a minimum. In a wave propagation loss measurement section, a calculation is performed on the basis of an amplification factor of a reception amplifier, amplitude information and a base station transmission power information of a reception baseband signal to calculate a wave propagation loss of a reception signal, thereby estimating a propagation loss of transmission signal. The wave propagation loss information is inputted to a maximum amplification amount designation circuit to decide a maximum amplification factor. The maximum amplification amount designation circuit adjusts a maximum transmission power of the transmission signal by designating the decided maximum amplification factor to a transmission amplifier.

CDMA wireless transmission apparatus, CDMA wireless transmitter-receiver system and transmission power control method of the CDMA wireless transmission apparatus

A control method of searching for a neighboring cell of a mobile station communicating with a base-station is provided in a direct sequence CDMA mobile communication system which transmits information by carrying out double modulation using a first spreading code group and a second spreading code. The first spreading code group includes spreading codes that have a same repetition period as an information symbol period and are used in common by the base stations, and the second spreading code has a repetition period longer than the information symbol period. The base stations are assigned different second spreading codes. The control method stores at least one second spreading code and its phase into a first table, which second spreading code corresponds to a perch channel whose second spreading code and phase are known; stores a second spreading code used by a neighboring base station into a second table; searches for a perch channel whose second spreading code and phase are unknown; and searches for a perch channel whose second spreading code and phase are known. The neighboring cell search method can save the power consumption and time required for the mobile station to carry out the cell search with preventing an increase in the total cost of the system.

Control method of searching neighboring cells, mobile station, and mobile, communication system

Information stored in an IC card which can be set to a block state, where any functions permitted to a user authority holder is not effective and an unblock password is required to set the IC card back to an initial state, is more secured than that stored in an IC card without the block state. The IC card of the present invention is further provided with a counter counting the number of incorrect unblock passwords, and is set to a more secured state of operation where only administrative authority holder can release the IC card.

IC card having block state of operation and method of providing information security for the same

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 using ATM cells, and with the mobile stations using the CDMA signals by mapping a plurality of logical channels into a plurality of physical channels. The CDMA signals are spreading using two types of spreading code sequences, that is, a short code and a long code.

An exclusive OR of outputs from a plurality of shift stages of an M-series generator is formed, thereby obtaining an M-series which has a desired delay, which in an example is a three bit delay with respect to the output code from the generator. Similarly, outputs from a plurality of shift stages are combined and an exclusive OR thereof is formed to provide another delayed M-series. An exclusive OR of each output from the simultaneously delayed code generator and an output from another M-series generator is formed, thus simultaneously obtaining a plurality of Gold code series.

Simultaneous plural code series generator and CDMA radio receiver using same

A CDMA radio receiver includes a plurality of reception fingers for effecting a dispreading of a received signal with a plurality of spread codes to derive received data. The receiver includes a plural code generator for simultaneously generating and supplying spread codes to the plurality of reception fingers, and a controller for designating a plurality of spread codes which are to be generated and supplied to the plural code series generator and for specifying to which finger they are to be supplied. The plural code series generator includes a shift register having a plurality of shift stages in which a first initial value is loaded by the controller and adapted to be subject to a shift operation in synchronism with a clock.

A control method of searching for a neighboring cell of a mobile station communicating with a base station is provided in a direct sequence CDMA mobile communication system which transmits information by carrying out double modulation using a first spreading code group and a second spreading code. The first spreading code group includes spreading codes that have a same repetition period as an information symbol period and are used in common by the base stations, and the second spreading code has a repetition period longer than the information symbol period. The base stations are assigned different second spreading codes. The control method stores at least one second spreading code and its phase into a first table, which second spreading code corresponds to a perch channel whose second spreading code and phase are known; stores a second spreading code used by a neighboring base station into a second table; searches for a perch channel whose second spreading code and phase are unknown; and searches for a perch channel whose second spreading code and phase are known. The neighboring cell search method can save the power consumption and time required for the mobile station to carry out the cell search with preventing an increase in the total cost of the system.

Control method of searching neighboring cells, mobile station, and mobile communication system

In CDMA mobile communication systems, there are cases in which communications are interrupted with the local base station while the mobile station is searching for channels other than the communication channel. A method is offered of preventing loss of information due to interruptions in such a case. There are a first transmission step for transmitting signals from the mobile station to the base station at a transmission rate R and a transmission output level P (when the transmission output is p in FIG. C), a suspension step of suspending signal transmissions from the mobile station to the base station (when no transmission output power as shown in the same drawing), and a second transmission step of transmitting signals from the mobile station to the base station at a transmission rate R higher than the transmission rate R and a transmission output level P higher than the transmission output level P (when 2p in the same drawing). Due to this second transmission step, it is possible to transmit information which was not transmitted during the suspension period.

Signal strength measurement method and device

A mobile station according to the present invention that is capable of connecting simultaneously to a plurality of base stations comprises a reception radio portion and TPC bit detecting portions, for receiving and detecting TPC bits (transmission power control signals) from the plurality of base stations during soft handover; a combining portion, for combining the detected TPC bits to determine a combination signal; and a transmission power control deciding portion, for controlling the transmission power of the mobile station based on the combination signal determined by the combining portion. A method according to the present invention governs use of the mobile station hereof.

Transmission power control method, mobile phone, base station, and recording medium

A receiving method using a CDMA radio receiver with a plurality of receiving fingers each composed of a code generator, a correlator and a detector. In a visited cell search while in the ON-state of the power supply, different long-period spreading codes are set in the code generators, and if none of correlated outputs from the correlators respectively corresponding to the code generators exceed a threshold value, then new different long-period spreading codes are set in the code generators. If any one of the correlator outputs exceeds the threshold value, the mobile station is decided as staying in the cell corresponding to the long-period spreading code set in that correlator, and this long-period spreading code and time points at which peaks of correlator outputs were obtained with the long-period spreading code are set in the receiving fingers in descending order of the magnitude of correlation peaks.

Method and apparatus for receiving CDMA radio communication

Growing community of inventors

Kanagawa, Japan

Akihiro Higashi