Abstract: 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.

Abstract: 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 djusts a maximum transmission power of the transmission signal by designating the decided maximum amplification factor to a transmission amplifier.

Abstract: 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.

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: 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: 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 mobile communication system using spread spectrum, performing respective multiplications of an I and Q channel signals by a spreading code replica, integration over one spreading code period, and square-law detection of the integrated signals to remove data modulation components and residual carrier frequency components. The square-law detected signals are added to obtain signal power over one spreading code period while updating the clock phase of a digital control clock generator. The information of power is stored in a memory in an acquisition mode controller, and the clock phase of the digital control clock generator 30 is fixed at the spreading code replica phase at which a maximum correlation detection power over one spreading code period is obtained. Subsequently, a confirmation mode is started for confirming the spreading code acquisition phase.

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: A base station selection scheme for a CDMA cellular system capable of reducing the transmission power of the mobile station and increasing the subscriber capacity, by accounting for the uplink interference power at each base station. An uplink interference level is measured at each base station, while a perch channel is transmitted from each base station to the mobile station, and a perch channel reception level of the perch channel transmitted from each base station is measured at the mobile station. Then, a connection target base station to be connected with the mobile station is selected according to a received SIR (Signal to Interference Ratio) of each base station determined from the perch channel reception level measured at the mobile station and the uplink interference level measured at each base station.

Abstract: A coherent detection method including a step of estimating a transfer function of a propagation path using pseudo-pilot signals which consist of some information symbols adjacent to pilot signals. The information symbols in the pseudo-pilot signals are assumed to be known. The method includes the steps of estimating the transfer functions using the pilot signals, carrying out interpolation coherent detection of the information symbols using the estimated transfer functions, storing the detection results as the pseudo-pilot signals, reestimating the transfer functions associated with the information symbols corresponding to the pseudo-pilot signals by using the pseudo-pilot signals and the corresponding received signal under the assumption that the pseudo-pilot signals have a known correct pattern, and carrying out the interpolation coherent detection of the individual information symbols by using the transfer functions obtained by the reestimation.

Abstract: CDMA mobile communication method and system for realizing an autonomous distributed control of radio channel allocation, a synchronization control for a smooth establishment/switching, and a VOX control for a capacity increase are provided. At either one station of each base station and the mobile station, one of a plurality of prescribed short spread codes is selected, and a data sequence to be transmitted is spread by using the selected short spread code and a prescribed long spread code and then transmitted, while at another one station, the data sequence before spreading is reproduced and received by despreading the data sequence from that either one station by using the selected short spread code and the prescribed long spread code.

Abstract: A repeater improving the effect of a RAKE reception. A received signal from a base station parallelly passes a first path including a first delay circuit and a second path including no delay circuit, and is transmitted to a mobile station. A received signal from the mobile station parallelly passes a third path including a second delay circuit and a fourth path including no delay circuit, and is transmitted to the base station. The delay time of the delay circuits are set at one chip interval or more of a spreading code. This forcedly produces multipath waves which are resolvable by a RAKE receiver. The RAKE receiver estimates amplitudes of desired wave components for individual delayed waves, performs weighting of the respective delayed wave components from detectors by using the estimated amplitudes, and makes symbol decision in terms of the combined weighted signal.

Abstract: A code sequence generator having a register for holding n-bit code, and a calculation circuit for performing matrix calculation on the content of the register, and sequentially generating a code sequence by feeding back the calculation results to the register. The matrix which is set in the calculation circuit is changed by selectively reading a matrix from a memory circuit that stores precalculated matrices. This makes it possible to set a desired register state in a short time even if the desired code sequence is very long, and to generate any code sequences without changing the rate of a clock signal.

Abstract: A base station of a CDMA communication system includes a transmission de-correlator for eliminating interferences between communication channels of a downlink. The transmission de-correlator has a memory storing a set of data representative of the products of transmission information bits for the respective channels, and the sums of the products of the spread code data sequences for the respective channels, and the elements of an inverse matrix with respect to a predetermined matrix of a cross-correlation between the spread code data sequences for the respective channels. The sums correspond to additions of the products along a direction of columns or to additions of the products along a direction of rows of the inverse matrix. A counting device is operative for causing the memory to sequentially output the data therefrom. An adder serves to calculate a sum of the data outputted from the memory.

Abstract: A received signal of a control channel of each cell is despread by each spreading code in a correlation detector. The received level of the despread output in a window, including its peak, is measured in a level measuring part and an interference signal level outside the window is also measured. In a control part the difference or ratio between the measured received level and the interference signal level is obtained as a comparison signal for each spreading code, and the comparison signal is compared in terms of magnitude to thereby determine the visited cell of a mobile station.

Abstract: An apparatus for heat treating and quickly cooling substrates. The apparatus includes a cylindrical furnace core tube for containing substrates, a heater enclosing the furnace core tube, and outer cylinder enclosing and containing the furnace core tube and the heater, a blower for drafting cooling air to the space between the furnace core tube and the outer cylinder along the longitudinal direction of the furnace core tube, and a switching valve connected between the blower and both ends of the outer cylinder for switching the direction in which the cooling air travels. Since the direction of the cooling air is changed, the entire furnace core tube is uniformly cooled.