Abstract: A short cell management unit capable of carrying out OAM (operation, administration and maintenance) functions on short cell connection basis (newly defined F7 flow) included in VC (virtual connection) in addition to OAM functions on VC basis (F5 flow) which are defined in a conventional B-ISDN. The F7 flow includes the entire OAM functions such as fault management, performance management, which are included in F4 and F5 flows that carry out the management by causing a standard OAM cell defined in the existing B-ISDN to flow. To implement this, a variable length OAM cell is newly provided as one of the short cells, and a base station and a switching office are newly provided with a short OAM cell/standard OAM cell translator for carrying out mapping between the short OAM cell and the standard OAM cell. Furthermore, a generally used standard OAM processor is used for implementing the management functions (F4 and F5 flow) defined in the standard B-ISDN.

Abstract: An automatically gain-controlled analog received signal is AD converted to a digital signal, which is subjected to quadrature demodulation processing through operation. The quadrature demodulation result is subjected to low-pass filter processing through operation, that is, a digital detection is performed by software processing to a variable in each software processing in accordance with changes in the modulation method of the received signal and in the symbol transmission rate.

Abstract: A control channel is searched for call waiting in a mobile station where the power supply for a receiving circuit is turned off during a break time of receiving level measurements, wherein in a first control channel selection mode, all the control channels are divided into a plurality of groups, the receiving levels of the control channels are measured group by group intermittently and sequentially. The intermittent measurement of these groups are repeated until a control channel having a receiving level equal to or greater than a first predetermined value is detected. When a receiving level equal to or greater than the first predetermined value is detected, the receiving levels of all the control channels are measured in a second control channel selection mode.

Abstract: A coherent tracking apparatus for a CDMA receiver capable of achieving high accuracy tracking by suppressing noise. It includes a demodulation correlator for detecting correlation between a received spread signal and a demodulation spreading code replica inphase with a received spreading code included in the received spread signal by multiplying them, an absolute coherent detector for demodulating information data through absolute coherent detection of the correlation signal (despread signal) fed from the demodulation correlator, a tracking correlator for detecting correlation by multiplying the received spread signal by a pair of tracking spreading code replicas whose phases are shifted by .+-.

Abstract: A variable rate transmission method that can vary the transmission rate of data. A transmitting side supplies a transmitted data sequence to an error detecting encoder 105 and a frame memory 103. The frame memory 103 stores data of a variable length to be transmitted in one frame. The error detecting encoder 105 calculates an error detecting code (such as CRC code) for each frame of the transmitted data. A multiplexer 104 adds the calculated error detecting code ahead of the transmitted data to place it at the initial position of the frame, and sequentially outputs the data sequence frame by frame. A receiving side calculates an error detecting code of the data in each transmitted frame in the same manner as the transmitting side, and compares the calculated error detecting code with the error detecting code at the initial position of the frame. The end bit of the frame data is decided as a position at which the two error detecting codes coincide.

Abstract: For the transmission of variable length coded data blocks, a threshold arithmetic calculation circuit (9) obtains a threshold from an average of the bit lengths of the variable length coded data blocks for each group of such block, and the judgment circuit (10) makes a judgment as to whether or not those variable length coded data blocks have bit lengths exceeding the threshold of the block group to which such data blocks belong. Then, a block divider circuit 11 divides the variable length coded data blocks having bit lengths exceeding the threshold into blocks having small bit lengths. Each block thus obtained is fixedly equalized in bit length to an average length level and transmitted in that condition.

Abstract: A scheme for enabling a roaming call termination connection for a mobile subscriber between mobile communication networks adopting different roaming number allocation schemes is disclosed.

Abstract: In a mobile communication system, a data communication fixed station 3 and a voice communication fixed station 4 control a common service area, the connection between a mobile station 5 and the data communication fixed station 3 can be quickened. The data communication fixed station 3 notifies, sequentially, the voice communication fixed station 4 of channel informations (e.g., usable channels, traffic quantity). The voice communication fixed station 4 receives the channel information via a broadcast channel for voice communication, and broadcasts the channel information to the mobile stations. When the mobile station 5 is to execute packet communication with an ISDN 1 via the data communication fixed station 3, the mobile station 5 selects an appropriate channel among the channels broadcasted thereto, and notifies the data communication fixed station 3 of the selected channel.

Abstract: A scheme for controlling transmission powers during a soft handover in a CDMA mobile communication system, in which the receiving quality can always satisfy the reference quality even when a relationship between the receiving qualities at the base stations is reversed within the selective combination interval. In this transmission power control scheme, one radio channel among a plurality of radio channels is selected as a reference radio channel at the prescribed selective combination interval, and then a transmission power control is carried out at a prescribed transmission power control interval so that a receiving quality of the reference radio channel satisfies a prescribed reference quality, while not switching the reference radio channel within the prescribed selective combination interval.

Abstract: Input is applied to a two-partition circuit that substantially equally distributes input power into two partitions having a phase difference of 90.degree., and the thus-distributed output is applied to a first driver that generates circularly polarized wave. The two outputs of the second driver, in which the circularly polarized waves generated from the first driver are coupled, are combined in a combining circuit. The end portion of the opening of the sealed case incorporating the first driver fits together with the end portion of the opening of the sealed case incorporating the second driver such that the two sealed cases together with the first and second drivers may rotate relative to each other around their cylindrical axis. The phase difference between the input of the two-partition circuit and the output of the combining circuit changes according to the relative angle of rotation around the cylindrical axis between first and second drivers.

Abstract: A transmission power control scheme for a mobile communication system for suppressing the transmission power to an absolutely necessary minimum level, and increasing the subscriber capacity by reducing an amount of interference. In this scheme, at a time of controlling a transmission power of each radio channel at one of the base station and the mobile station so as to make a difference between a target CIR and a reception CIR of each radio channel at another one of the base station and the mobile station smaller, the target CIR for all radio channels at that another one of the base station and the mobile station are set independently, and/or the target CIR for each radio channel is changed at that another one of the base station and the mobile station, according to a channel quality of each radio channel at either one of the base station and the mobile station.

Abstract: In a broadband antenna using a semicircular conductor disc, a semicircular cutout is formed in the semicircular radiator concentrically therewith. Alternatively, a semicircular arcwise radiating conductor with a semicircular cutout defined concentrically therewith is bent into a cylindrical shape to form a radiator.

Abstract: A method for setting up perch channels in a mobile communication by a cellular system, capable of setting up a perch channel and a perch channel list for surrounding base stations at each newly provided base station autonomously. At the newly provided base station, reception levels of signals transmitted by mobile stations to surrounding base stations are measured by scanning uplink control channels corresponding to perch channels, and a perch channel of the newly provided base station and a perch channel list to be signaled by the newly provided base station are autonomously set according to the measured reception levels.

Abstract: A private mobile communication system serves to support communication between mutual portable or mobile radio telephone equipment which are registered in the system, and communication between the portable or mobile radio telephone equipment and a telephone connected to a public network. A portable or mobile radio telephone equipment which is not registered in the system transmits a request for call to the public network through a private control channel controlling section. A radio base station in the system transfers the request for call transmitted through a private channel to a PBX. The PBX serves to support the call to the public network in response to the request for call transmitted through the private channel.

Abstract: The communication terminal (102) is provided with a notice unit (204) for recognizing a state of use of itself and states of use of the data terminals (103.sub.1) through (103.sub.n) and notifying a result of the recognition to the network side, whereas the network system (101) is provided with a storage unit (303) for registering a communication terminal in which the communication terminal (102) and at least one of the data terminal (103.sub.1) through (103.sub.n) became usable and deleting the registration of the communication terminal (102) or a communication terminal in which the data terminals (103.sub.1) through (103.sub.n) became unusable, in accordance with a result of the notice made by the notice unit (204), so that a receiving possible state of the communication terminal (102) is preliminarily registered on the side of the network system (101). Moreover, the receiving standby state is discriminated between a voice-only standby state and a voice and packet simultaneous standby state.

Abstract: A mobile communication system is provided in which a base station commands a mobile station (or field monitor) to measure the field strength for a specific channel. The mobile station reports the measured results to the base station. The measured results are used in conjunction with base station identification codes to obtain a single representative value which is used to determine what channels can be selected and used by the system. This enables an existing cellular system to be utilized as a first mobile communication system, and makes it possible to construct a second mobile communication system in the same area as the service area of the first system.

Abstract: The present invention relates to an echo canceler for training an echo path estimation without providing a hindrance to a speech. The echo canceler of the present invention includes a pseudo noise generator for generating a certain pseudo noise. This pseudo noise is forcibly supplied to a transmission line for transmitting a far-end talker's voice. Here, in the case where the far-end talker's transmitting speech level is faint or the far-end talker is in a speechless condition, a certain correlation is established between the pseudo noise and a signal of the transmission line for transmitting the near-end talker's voice. Based on such a correlation as just mentioned, a coefficient for generating an echo replica is calculated. Therefore, a training for estimating an echo path is performed based on the pseudo noise and without depending on the far-end talker's voice, thereby enabling to generate an appropriate echo replica.

Abstract: A transmitter receiver implementing both frequency division duplex and time division duplex in one device in a CDMA mobile communication system. In the FDD mode, data in an interleave memory in an interleaver is read at a predetermined read rate V.sub.R =V.sub.N, where V.sub.N is a normal rate. In the TDD mode, a transmitting carrier frequency is set identical to a receiving carrier frequency, and the read rate V.sub.R of the interleave memory and the write rate V.sub.W of the deinterleave memory are set at V.sub.R =V.sub.W >2V.sub.N. The transfer rate V.sub.T from column to column of the memories are set identical in the FDD mode and the TDD mode. This makes it possible to create a vacant duration while transferring from column to column, and to perform reception or transmission during the vacant duration. The remaining operation of the TDD mode is the same as the operation of the FDD mode.

Abstract: A communication method and system which can enlarge the communication capacity using a rather simple system. The communication method and system provides different spreading codes to two signal systems at a receiving station.

Abstract: In a time diversity receiver, where in time diversity is performed using the detector output, without any use of a receiving level detection circuit, thereby simplifying the receiver circuitry and reducing power consumption.