Abstract: Received baseband signals from a plurality of antennas 111 to 11Q are linearly combined through multiplication by weighting coefficients, then a decision signal is delayed for one symbol duration, and the delayed signal is multiplied by a feedback filter coefficient wb* to generate intersymbol interference, which is subtracted from the linearly combined output y(i). The subtracted output is subjected to a signal decision to obtain a decision signal, then the difference between the input into a decision unit 17 and the decision signal is obtained as an error signal e(i), and weighting coefficients w1* to wQ* and the feedback filter coefficient wb* are estimated in a parameter estimation part 71 so that the square of the error signal e(i) is minimized.

Abstract: The present invention provides a path-diversity system featuring a small-size phase compensating circuit. This circuit calculates a compensating coefficient according to the signals of a pilot block or a pair of pilot blocks surrounding an information block, and then compensates information signals thereafter by the calculated compensating coefficient.

Abstract: In the method of handover control, when a mobile station recognizes that the mobile station has moved to an overlapping area, the mobile station notifies this fact to a network side and in response the network side sets up only a communication channel between a handover target base station and an exchange station for controlling that handover target base station, without setting up a radio channel between the handover target base station and the mobile station, while continuing the communication by not releasing the communication channel between the currently located base station and the exchange station and the radio channel between the currently located base station and the mobile station, so that it becomes possible to reduce a transmission control load for transmission between the base station and the exchange station as well as a control load for controlling the exchange station itself.

Abstract: In the balance adjustment using a pilot signal in a distortion detector and a distortion canceller of a feed-forward amplifier for amplifying a CDMA transmission signal, a pilot code is spread by a long code different from that of the CDMA transmission signal to obtain the pilot signal. The pilot signal is converted to a signal of the transmission frequency band, and the converted signal is injected into the transmission signal at the input side of the amplifier. The pilot signal frequency band is detected from the output of an auxiliary amplifier of the distortion canceller and converted to the base band, thereafter being despread to detect the pilot signal (code).

Abstract: A paging scheme for a mobile communication system which is capable of suppressing the power consumption of the mobile station by reducing the intermittent ratio while keeping an average time required for the paging shorter than a case of merely increasing a number of time-slots. Each base station transmits a paging channel on which a paging signal for each mobile station is transmitted at intermittent timings, where the paging channel has a data transmission rate higher than a required paging channel rate of the mobile communication system, so as to shorten a transmission time of the paging signal for each mobile station. Then, each mobile station judges a presence or absence of the paging signal for that mobile station by receiving the paging channel at these intermittent timings. The paging channel may have a data transmission rate which is variable.

Abstract: A data transmission device comprises a transmitter device and a receiver device. The transmitter device divides a data string to be transmitted into an original data string requiring protection against code error and a data string requiring no protection. The transmitter device then carries out an error detection code adding operation and error correction coding at a redundancy code rate of 1/N on the original data string to generate a coded data string. The transmitter device divides the coded data string by N, and outputs the N divided coded data strings and the data string requiring no protection on a communication line under a time division multiplexing control. The receiver device receives the N coded data strings and the data string requiring no protection.

Abstract: 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.

Abstract: A mobile station position estimation scheme for a cellular mobile communication system which is capable of estimating a position of a mobile station in a simple manner even in the general cellular mobile communication systems in which base stations are not synchronized. According to this mobile station position estimation scheme, a first signal sequence and a second signal sequence which are uniquely predetermined for the mobile station are exchanged between the mobile station and the base station, and then a position of the mobile station is estimated at one station among the base station and the mobile station, by obtaining a phase difference between the first signal sequence and the second signal sequence and calculating an estimated distance between the base station and the mobile station according to the phase difference.

Abstract: Achieving high speed spreading code synchronization of a forward link control channel. A control channel information signal and traffic channel information signals are each spread by different first spreading codes which are fed from a first spreading code (short code) generator (11), and which have a period equal to the period of an information symbol. Subsequently, only the control channel information signal is spread by a third spreading code which is fed from a third spreading code (long code masked portion complex conjugate code) generator (12), and which has a form of complex conjugate of a long code (second spreading code) used for spreading in common. The signals of the entire channels are summed up by an adder (13) at appropriate timings, and the resultant sum is spread by the second spreading code fed from a second spreading code generator (14), thereby being output as a spread modulation signal.

Abstract: In a communication system across an in-office PC system (10) and an in-enterprise LAN system (20), in order to perform a transmission of packet data from a DDTE (22) on the LAN side to a M-DTE (14) on the personal station side without a need of a provision of complicated means, when receiving packet data addressed to the M-DTE (14) from the DTE (22), a LAN side control unit (23) transmits a connection request including the incoming packet address to a PBX (11) of the in-office PC system (10), the PBX (11) notifies a PS (13) of the incoming signal for the packet address through a CS(12), and on the other hand, the M-DTE (14) connected to the PS (13) acknowledges the incoming signal through the PS (13) and the CS (12) when the packet address which received this notice corresponds to the M-DTE (14), thereby achieving a connection. After the connection, the control unit (23) transmits packet data to the M-DTE (14).

Abstract: In CDMA mobile communication of the packet switching mode which is one-way, the packet is transmitted to divide to a frame unit. In this time, the first, the second and the third transmission timing which are obtained to divide to three pieces the predetermined frame are set up for increasing the transmission efficiency by realizing the retransmission of the frame unit, as the transmission timing of a backward control signal in a backward channel,. Base station 100 transmits a forward signal (a forward control signal and an user data signal) by using code A (a forward channel) at any frame. When the forward signal is received at this frame by mobile station 70, mobile station 70 transmits a receiving acknowledgment signal (a backward control signal) of the forward signal by using code A' at the first transmission timing of the next frame.

Abstract: A cell selection scheme for a CDMA mobile communication system which is capable of reducing an amount of interference power and thereby preventing the degradation of the system capacity. In this scheme, each base station transmits a perch channel which is spread by using a spread code assigned to each base station. Then, a mobile station receives more than one perch channels transmitted from more than one base stations, calculates a transmission attenuation value of each received perch channel, and judges a located cell according to calculated transmission attenuation values of these more than one perch channels.

Abstract: An object of the present invention is to reduce the control time required when a channel handover is performed in a mobile communication system. The conventional system has such shortcomings that a long time is required for re-designating a channel when a channel handover procedure results in failure. Particularly, in the common access type system, there is such a problem that since a channel handover is required to be performed several times during a channel handover procedure, an extra time is required for performing the handover procedure. The present invention has a plurality of base stations for covering the service area, and a mobile station for performing a communication with the base stations through radio channels.

Abstract: A scheme for intermittent reception of paging signals in a mobile communication system, in which each base station repeatedly transmits a frame which contains: at least one regular reception section having a plurality of paging indication regions provided in corresponding to a plurality of groups, in which a paging presence information for indicating a presence of a paging with respect to a mobile station of a group is set in a paging indication region corresponding to that group when a paging with respect to a mobile station of that group occurs; and a mobile station alerting section having a plurality of identification information setting regions provided in correspondence to a plurality of paging indication regions, in which an identification information of a mobile station called by a paging indicated by a paging indication region is set in an identification information setting region corresponding to that paging indication region.

Abstract: A CDMA demodulating apparatus with an improved interference canceling effect when there are a large number of communicators. A reception signal having a frame configuration in which a pilot signal of a known pattern is inserted between information signals is received from a plurality of communicators. Transmission data of each communicator is demodulated, an interference canceler for estimating is provided in a plurality of stages, in each channel of each stage, a variation of transmission path is estimated in each path to achieve data demodulation and estimation of interference replica. The later the stage, the more error of interference signal replica can be reduced, thereby improving the interference canceling effect. An even better effect can be obtained when interference canceling is performed after detecting a reception level of each channel by summation of reception power of each path of each channel, and channel ranking is determined in the order of higher reception level.

Abstract: In an error control device, an error correction decoding portion 33 selects a bit position which has low reliability from the received signal by means of a predetermined bit number, generates error patterns by assuming that the errors exist at the bit position, and carries out modified Chase decoding for the received signals on the basis of each error pattern in modified Chase decoding portion 332. Modified Chase decoding portion 332 calculates the reliability of each error pattern by using the reliability of each bit in the received signal.

Abstract: An ATM transmission system which transmits voice data in an asynchronous transfer mode (ATM). It implements compression of a mute section over a channel by detecting the mute section of a call and by physically suppressing its transmission over the channel as an ATM cell. A transmitting side detects the mute section, generates vocal/mute information, and generates a mute start cell and a mute end cell. A receiving side generates a mute section at a fixed interval when receiving the mute start cell, and returns to a normal receiving mode of a speech spurt cell immediately when receiving the mute end cell. The suppression of the mute section makes it possible to reduce the occupied bandwidth, and to increase the channel efficiency.

Abstract: In a system with a spread spectrum transmitter and receiver employing composite spreading codes, the transmitter spreads, in a spreading part, a baseband modulated signal by a short code from a short code generator and a long code from a long code generator with a longer chip period than that of the short code and then transmits the spread baseband modulated signal. The receiver despreads a spread baseband received signal in a receiving part by a pair of short and long codes in one despreading part to obtain a baseband modulated signal of a direct path and despreads the spread baseband received signal by the pair of short and long codes delayed by a multipath delay time difference in the other despreading part to obtain a baseband modulated signal of a delayed path, and the baseband modulated signals thus obtained are diversity-detected to obtain a detected baseband signal.

Abstract: A wire line data transmission scheme in a mobile communication system for reducing the wire line transmission const. Radio state qualities of a plurality of radio channels between the plurality of base stations and the mobile station are measured, and a validity and a redundancy in composition of each radio channel is judged according to the corresponding measured radio state quality. Then, a transmission in the wire line transmission paths is controlled by stopping a transmission of transmission signals for those radio channels which are judged as invalid or redundant according to the obtained judgement result. All of measuring, judging, and controlling can be carried out by each base station, or by the mobile station. Also, measuring and judging can be carried out by the mobile station while controlling is carried out by each base station, or measuring can be carried out by the mobile station while judging and controlling can be carried out by each base station.

Abstract: Multiplex transmission apparatus 10 on the transmitting side multiplexes received signals from non-voice signal input output apparatus 14 and voice signal input output apparatus 16, and also transmits the multiplexed signal from communications network 30 by digital portable telephone 12 on the transmitting side. The digital portable telephone transmits a signal per 20 msec, so that multiplex transmission apparatus 10 alternately transmits the voice signal and the non-voice signal at an interval of 20 msec, for example. Multiplex transmission apparatus 20 sorts out the voice signal and the non-voice signal from the supplied signal by checking the error detecting code of the supplied signal. Multiplex transmission apparatus 20 can judge the type of the signal according to the type of the error detecting code, because a different error detecting code is added to each signal.