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 data transmission method, data transmission system, and a transmitter and receiver are provided which can implement higher quality variable rate transmission by making a more positive rate decision. In a variable rate transmission method transmitting fixed time length frames, each including variable length transmitted data, a transmitting side transmits user data plus an error detecting code, and a receiving side, assuming the entire transmittable final bit positions of the frame data, carries out Viterbi decoding of the frame data to the final bit positions.

Abstract: A DS-CDMA transmission method capable of improving the accuracy of channel estimation using pilot symbols by eliminating cross-correlation between pilot symbols inserted into code channels in CDMA multiplexing carrying out fast signal transmission. In each frame assembler, the pilot symbols, which are used for channel estimation for coherent detection, are inserted into coded information data on code channels at fixed intervals, and then the data is modulated by the modulator. The modulated data symbols in each code channel from the modulator are spread by the spreading modulator, the pilot symbols are spread using a spreading code, whereas the information symbols are spread using different spreading codes assigned to respective code channels. The spread signals of the code channels are summed up by the adder to be transmitted.

Abstract: When errors occur in a received code sequence, an error concealment routine part 130 is actuated and a correct code sequence is generated based on a code sequence received before the errors are detected. A decoding routine part 21' executes a decoding process based on this code sequence and updates the internal state based on the decoded result. Thereafter, when the code errors are recovered, an error recovery routine part 140 is actuated. The error recovery routine part 140 re-estimates a correct code sequence during a time period when the errors are detected, based on a code sequence received before the errors are detected and a code sequence received after no more errors are detected, and generates a second estimated code sequence. The decode process part 21' executes the decoding process based on an internal state information for retaining the second estimated code sequence in an internal state storage part 23', and updates the internal state information based on the decoded result.

Abstract: A CDMA communication method capable of providing a multi-rate user with high quality transmission using a spreading sequence selected from sequences which consist of multilayer sequences arranged in a hierarchical tree structure. A higher level sequence C.sub.16 (1) and its inverted sequence C.sub.16 (1) are included in its lower level sequences {C.sub.32 (1), C.sub.32 (2)} and {C.sub.64 (1), C.sub.64 (2), C.sub.64 (3), C.sub.64 (4)}, for example, and a sequence from a higher level is selected to transmit a higher rate data: The C.sub.16 (1) is used to transmit data whose peak rate is twice the peak rate of the data transmitted using its lower level sequences {C.sub.32 (1), C.sub.32 (2)}, and four times (=2.sup.2) that of the data transmitted using the sequences {C.sub.64 (1), C.sub.64 (2), C.sub.64 (3), C.sub.64 (4)}. The C.sub.16 (l), however, cannot be selected if any one of its lower level sequences {C.sub.32 (1), C.sub.32 (2)} and {C.sub.64 (1), C.sub.64 (2), C.sub.64 (3), C.sub.

Abstract: A transmitted signal is enciphered or concealed to thereby prevent interference, even when data indicative of the receiver terminal is made public because of the use of a common access channel. In the transmitter, in a random-number bit adder 6, a random-number .alpha. (digital signal) generated by a random-number generator 5 is inserted into a transmitting data signal DA generated by a transmitting data generator 1, and the resultant is outputted as a signal (DA, .alpha.). An encipherment processor 2 enciphers the signal (DA, .alpha.) and outputs it as a signal (DA, .alpha.)'. In the receiver, this signal (DA, .alpha.)' is deciphered into (DA, .alpha.), and the random-bits .varies. are removed from (DA, .alpha.) to restore the signal DA.

Abstract: A radio channel initial transmission scheme for a mobile communication system which is capable of reducing an unnecessary interference with respect to the other radio channels as well as an unnecessary consumption of a battery of a mobile station. In the present invention, this is realized by not carrying out a transmission of the unnecessary general information during an initial period of a radio channel set up. More specifically, only the constantly necessary information among radio channel transmission signals is initially transmitted from a transmitting side of the base station and the mobile station, at a time of setting up a radio channel between the base station and the mobile station, and then the constantly necessary information and the general information other than the constantly necessary information are subsequently transmitted from the transmitting side, after a receiving side of the base station and the mobile station becomes ready to receive the radio channel properly.

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 communication equipment and telephones connected to a public communication network. Portable or mobile radio telephone equipment which is not registered in the system transmits a call request to the public network through a private control channel controlling section. A radio base station of the system transfers the call request through a private channel to a private branch exchange (PBX). The PBX serves to support the call to the public network in response to the call request transmitted through the private channel.

Abstract: Enabling reception quality to be improved and the capacity in terms of the number of simultaneous users in a cell to be increased, and speeding up the establishment of spreading code synchronization and the convergence of weighted coefficients, by feedback controlling weighted coefficients such that desired signal power to interference power ratio (SIR) becomes maximum. A coherent adaptive diversity configuration is employed to which absolute coherent detection is applicable. Adaptively feeding weighted coefficients back to diversity branches makes it possible to reduce the influence of the interference power from other users, and thus to increase the capacity in terms of the number of simultaneous users in the cell. Furthermore, the direction that provides the maximum received SIR is determined while rotating antennas in a state of having directivity with a predetermined angle range.

Abstract: A mobile communications system including a voice message function in both a communications network (10) and a mobile station (20). If the mobile station (20) does not respond, the communications network responds instead thereof, stores a message, and notifies the mobile station of the presence of the message. The mobile station requests the transfer of the message when accessible. The message can be positively sent to a mobile station even if it is not accessible for a long time.

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 generating an appropriate echo replica.

Abstract: A concrete circuit configuration is proposed of a multiplex transmitter for loading a standard ATM cell with multiplexed micro-frames which are each shorter than the standard ATM cell. The input micro-frames are delivered to a distributor 504 in the input order through an interface 503. The distributor 504 distributes the input micro-frames using distributing information input. The distributing information accords with the service condition of each connection or micro-frame. An extracting circuit 506 selects buffers in accordance with predetermined buffer selection logic. A cell cancellation monitor circuit 508 relinquishes micro-frames exceeding cell tolerable time periods T2-1-T2-m. A multiplexing processor 507 transfers the cell or a idle cell to a sender 511 in accordance with the cell transfer timing of the sender 511.

Abstract: An SIR measuring apparatus with a simple configuration capable of improving the accuracy of received SIR measurement in CDMA mobile radio equipment using pilot symbols. A received signal (20) is input to a synchronization detector (21) that regenerates the clock timing of symbols and frame timing equivalent to the repetition period of the pilot signal. An interpolating coherent detector (22) produces information symbols (23) obtained from the received signal (20) through absolute phase coherent detection. A decision signal power calculator (24) obtains desired wave power values. A quasi-interference power calculator (25) obtains differences between the power values of the information symbols and a fading envelope, and adopts the differences as the quasi-interference power. Integrators (26 and 27) integrate received desired wave power and quasi-interference wave power.

Abstract: An equalizer block forming part of a receiver compensates transmission path characteristics of a baseband received signal to generate a prediction signal, and differential-logic-converts a demodulated signal generated by demodulating the prediction signal to generate a differential-logic-conversion demodulated signal. A differential-detection demodulator block differential-detects the prediction signal from the equalizer block and subsequently demodulates the differential-detected prediction signal to generate a differential-detection demodulated signal. A selector block selects either the differential-logic-conversion demodulated signal from the equalizer block or the differential-detection demodulated signal from the difference-detection demodulator block.

Abstract: When a power supply to a mobile station is turned on, mobile station identification information is read out from a non-volatile storage of a subscriber information module. A module identification information is read out from the non-volatile storage of the mobile station. The mobile station identification information which is read out is collated against the own mobile station identification information, and module identification information which is read out is collated against identification information for the loaded subscriber information module. If the module identification information does not coincide, the communication processing information is read out from the loaded subscriber information module and is stored into the non-volatile storage of the mobile station to update its content. Identification information for subscriber information module is stored into the non-volatile storage of the mobile station to update it.

Abstract: The present invention provides a matched filter circuit available for processing long P/N codes in a small size circuit. A matched filter circuit according to the present invention performs the following processes in the proposed invention: i) sampling and holding circuits multiply part of the number of a long code; ii) multipliers are input in parallel to the sampling and holding circuit from the first multiplier register which can hold as many PN codes as the number of the sampling and holding circuits in i); iii) the PN codes are stored in the second multiplier register of the same capacity of the first multiplier resister when there is a PN code to be used sequentially to be PN codes; and iv) the PN codes in the second multiplier register are transmitted in parallel to the first multiplier register. The PN code is input to the second multiplier register in serial.

Abstract: A method and an apparatus for signal transmission in a CDMA mobile communication system which are capable of preventing an unnecessary increase of an amount of interference power due to the signal transmission through a radio channel and thereby preventing an unnecessary decrease of a system capacity. The radio channel transmission signals are transmitted through the radio channel, where the radio channel transmission signals contain the transmission signals which are formed by control signals or user signals and necessary signals which are necessary in maintaining the radio channel, and this radio channel transmission is controlled so that only signal portions for the necessary signals are transmitted without transmitting any other signal portions when there is no transmission signal to be transmitted.

Abstract: A RAKE receiver which is employed in a direct sequence spread spectrum communication system, and which can effectively receive multipath signals. A path searcher measures the amplitude of each path, selects N paths with larger amplitudes in descending order of magnitude, where N is the number of despreaders, and assigns the despreaders to the selected paths to despread the signals of the paths. This assignment of the despreaders to the paths is carried out such that a path with a large amplitude and a path with a small amplitude are assigned to adjacent despreaders and are input to the same pre-detection combiner. The outputs of the despreaders are combined by the pre-detection combiners, and detected by detectors whose outputs are RAKE combined by a post-detection combiner.

Abstract: In a communication system having a transmission station which transmits the data signal and a receiving station which receives the data signal, the transmission station consists of an adding means for adding an error detecting code showing a position of a transmission error, which occurs on said data signal, in said data signal to said data signal and a retransmission means for retransmission of a part in said data signal when said receiving station requests the retransmission of the part in said data signal. The receiving station consists of a judgment means for judging a position of the transmission error in said data signal on the basis of the error detecting code which is added by the adding means and a request means for requesting the retransmission of the part containing the transmission error in the data signal on the basis of the position of the transmission error.

Abstract: A CDMA mobile communication scheme capable of increasing a number of sectors while not increasing a number of perch channel spread codes and not jamming the control channel traffic, so as to obtain the capacity increase effect by the use of the sector configuration effectively. At the base station, a perch channel spread by an identical perch channel spread code assigned to the base station is transmitted from each one of at least two sectors of the base station. Then, upward signals from each mobile station are received at more than one reception sectors, the upward signals received at more than one reception sectors are despread by using an identical uplink spread code, and a maximal ratio combining of despread upward signals is carried out, in a case of carrying out a simultaneous reception at more than one reception sectors.