Abstract: A modulation apparatus is disclosed that enables great improvements in signal transmission rate in a limited frequency band as compared with conventional modulation schemes. Modulation apparatus 100 has first and second frequency-increasing SSB modulators 110 and 120. The modulators 110 and 120 are configured to have respective carrier frequencies with a difference by a frequency corresponding to the reciprocal of the symbol rate (i.e. fundamental frequency of the input symbol). Adder 130 combines a LSB signal obtained from the SSB modulator 120 set for a higher carrier frequency, and a USB signal obtained from the SSB modulator 110 set for a lower carrier frequency to obtain a modulation signal.

Abstract: A path search circuit according to the present invention has an orthogonal multi-beam forming section 4 for directional reception with a plurality of orthogonal multi-beams orthogonal one to another, correlation-operating sections 61–6M for correlation-operating outputs of the orthogonal multi-beam forming section 4 with a known signal, weight multiplying sections 81–8Nb for multiplying the output of the correlation-operating section 61–6M by a weight converted into a beam space, delay profile generating sections 91–9Nb for generating delay profiles from the output signals of the weight multiplying sections 81–8Nb, and a path detecting section 10 for detecting a reception timing and arrival direction of arrival path from the delay profile. This path search circuit can enhance the accuracy of path direction detection by the use of a directional reception signal, and further reduce the direction dependence of path timing detection accuracy.

Abstract: Baseband signal generator 107 outputs a transmission baseband signal with a coefficient for setting antenna directivity multiplied and a gain control signal to transmit power amplifier 114 and transmit power amplifier 114 amplifies the transmission baseband signal with a gain corresponding to the gain control signal and transmits the signal from antenna 102. ATT 118 attenuates the output signal of amplifier 114 according to the gain control signal, amplitude/phase comparator 110 calculates amplitude and phase errors between the attenuated signal with a frequency equalized by frequency conversion sections 120 and 121 and the input signal of amplifier 114 and phase/amplitude correction section 108 corrects the transmission baseband signal and gain control signal so as to eliminate the errors. This makes it possible to correct the amplitude and phase shifts of the transmission signal during a communication with other apparatuses and reduce the size and cost of the apparatus.

Abstract: An adaptive antenna radio communication device comprises a divided band direction estimating unit (4) for estimating the direction by calculating the cross correlations between a pilot signal and sub-carrier signals of the respective divided bands received by an array antenna (1) and calculating a spatial profile from correlation matrices determined by combining the correlation values between antenna elements of the different sub-carriers according to the output of the cross correlation calculation; a divided band array weight creating unit (5) for creating a weight of a receive array having a directional beam in the direction of estimation for each divided band; and a sub-carrier directivity creating unit (6) for creating a directivity by multiplication-combining the created receive array weight with the corresponding sub-carrier signal.

Abstract: A transmission weight computing section computes a transmission weight for directional transmission using an OFDM signal. A transmission correcting value memory section stores one correcting value for correcting the transmission weight for each sub-carrier of an OFDM signal or each band gathering a plurality of sub-carriers. A transmission weight correcting section corrects the transmission weight by the correcting value. A transmitting branch weights transmission data by a transmission weight outputted from the transmission weight correcting section on a sub-carrier-by-sub-carrier basis and delivers it to an antenna.

Abstract: Frequency converting sections 104a to 104n convert the frequency of modulated transmission signals to signals of an intermediate frequency by multiplying the transmission signals by a local signal; filter sections 105a to 105n attenuate the transmission signals after frequency conversion in the frequency regions outside the frequency band of the desired signals; and E/O sections 106a to 106n convert the transmission signals from electric signals to optical signals and output them to the O/E sections 151a to 151n of the base station apparatus 150.

Abstract: An amplitude-phase information acquiring section 105 acquires information indicating variation in amplitude and phase, using a probe signal that suffers the same variation in amplitude and phase as a communication traffic signal received by antennas suffers, between each antenna and the amplitude-phase information acquiring section 105. A received power measuring section 106 measures the received power of the communication traffic signal and the probe signal. A correction value control section 107 adaptively determines, based on the amplitude-phase information and the received power, a correction value for correcting for the variation of the amplitude and phase of the communication traffic signal. A correcting section 108, for each antenna, corrects for the variation of the amplitude and phase of the communication traffic signal by using the correction value determined based on the received power.

Abstract: A radio communication apparatus using an array antenna has a plurality of reception branches for conveying reception signals received at the antenna element of the array antenna, and a calibration branch for selecting one of the plurality of reception branches and conveying the reception signal. Channel estimations are made respectively on the reception-branch signals and a calibration-branch signal. RAKE composition is made on the channel estimation values, a result of which is used to detect amplitude and phase deviations on the reception branch thereby carrying out a correction.

Abstract: A path search circuit according to the present invention has an orthogonal multi-beam forming section 4 for directional reception with a plurality of orthogonal multi-beams orthogonal one to another, correlation-operating sections 61-6M for correlation-operating outputs of the orthogonal multi-beam forming section 4 with a known signal, weight multiplying sections 81-8Nb for multiplying the output of the correlation-operating section 61-6M by a weight converted into a beam space, delay profile generating sections 91-9Nb for generating delay profiles from the output signals of the weight multiplying sections 81-8Nb, and a path detecting section 10 for detecting a reception timing and arrival direction of arrival path from the delay profile. This path search circuit can enhance the accuracy of path direction detection by the use of a directional reception signal, and further reduce the direction dependence of path timing detection accuracy.

Abstract: A receiver having an array antenna estimates arrival directions of multiple paths that arrive with an angular spread. Consequently, arrival direction estimation accuracy can be ensured without increasing throughput even if the power every path is low by estimating an average arrival direction of an entire set of multiple paths having the angular spread from a result of one angular spectrum by multiple correlation operation units that perform mutual correlation operations with pilot signals for baseband signals received by the array antenna, a path detection unit that detects multiple arrival path receiving timings by generating a delay profile based on output of each of the correlation operation units, a path correlation value synthesis unit that synthesizes a correlation operation value calculated in the multiple correlation operation units and an arrival direction estimation unit that collectively estimates multiple path arrival directions using output of the path correlation value synthesis unit.

Abstract: A reception radio circuit 104 and a reception radio circuit 105 receive radio communication signals from a mobile station 109 and calibration signals from a CAL-CDMA radio signal transmission section 110 through respective a reception antenna 102 and a reception antenna 103, followed by performing down-conversion of received signals. A reception CDMA signal processing section B (for CAL) 107 measures characteristic errors of respective reception radio circuits while observing the calibration signals undergoing down-conversion, before holding the measured characteristic errors in a compensation table of a recorder 108. A reception CDMA signal processing section A (for communication) 106 performs CDMA demodulation processing of radio communication signals from the mobile station 109, which signals are subjected to the down-conversion, at the same time as observing operation of the reception CDMA signal processing section B (for CAL) 107, on the basis of the characteristic errors held in the compensation table.

Abstract: Tap coefficient string generator 103 converts to parallel a set of spreading codes generated by spreading code generator 102 for every one symbol, then gives them to the tap coefficient write terminal of programmable digital filter 106 via tap coefficient string write bus 104 and updates the tap coefficient of programmable digital filter 106 for every one information symbol. Upon the completion of reception of a section spread by the series of the Nth symbol, the shift register in programmable digital filter 106 is filled with the received signals of that section. If the series of the Nth symbol counted from the start of the long code is set as the tap coefficient of the programmable digital filter, correlative peaks appear at the matched filter output.

Abstract: The array antenna radio communication apparatus of the present invention combines the outputs of calibration desired signal generator 101 and calibration interference signal generator 102 using combination section 104. When changing the power of the combined calibration signal, it fixes the power of calibration desired signal to avoid phase rotations due to the power control section and changes only the power of the calibration interference signal by power control section. The array antenna radio communication apparatus supplies this combined calibration signal to a plurality of radio circuits simultaneously or alternately and performs reception processing on only the calibration desired signal by received signal processing section 112 and measures reception characteristics.

Abstract: Received signal provided via plural antennas 101 are memorized in memory 102. First weight controller 103 calculates the first weights by which the received signals are weighted, and second weight controller 104 calculates the second weights using the received signals. Multipliers 107 and 108 multiply the memorized received signals by the first weights, while multiply the memorized received signals by the second weights when a channel quality of radio signals deteriorates due to a change of the radio signal's direction of arrival Adder 109 synthesizes the multiplication results. Propagation path distortion compensator 110 estimates a deterioration of the channel quality using synthesis result to compensate.

Abstract: A high frequency signal received by an antenna is converted into a base-band signal through frequency conversion and quadrature detection in a radio circuit. Through search processing of the base-band signal in a timing control circuit, timings for a plurality of paths are detected, whereby first and second replica code timing indicating signals, a timing pulse, and first and second delay time indicating signals are generated. In first and second replica code generators, first and second replica codes are generated at timings indicated by the first and second replica code timing indicating signals, respectively. In first and second correlators, a correlation value of the base-band signal and the first replica code and a correlation value of the base-band signal and the second replica code are determined, respectively. In first and second synchronous detectors, output signals of the first and second correlators undergo synchronous detections, respectively, whereby first and second symbols are outputted.

Abstract: A pseudo-random noise series generator which can change the timing of generation of a PN series arbitrarily and with no instantaneous cut-off of the output. At the time of system start, the whole period or a certain beginning length of a PN series generated by a tapped shift register is stored into a RAM. The stored PN series is output from a position designated by an address signal. An address generator for generating the address signal on an externally applied timing control signal increments an address by one for each step from an initial value set by the timing control signal. In the case where a new timing different from the old timing is set by the timing control signal, the address is incremented or decremented instantaneously by a difference between the old timing and the new timing and a normal incrementing operation is thereafter started again.

Abstract: A spectrum spread receiver is provided with a delayed waveform phase determination circuit which determines whether or not a detected delayed waveform is in the phase as the previously-detected delayed waveform, and outputs a delayed waveform switch signal if they are out of phase with each other. If the delayed waveform switch signal is in an ON state, on the basis of the signal despread by a second despreading circuit 7 and the delayed waveform switch signal, a demodulation circuit 9 demodulates the first half and second half of a received signal, as a boundary is a received signal at which a delayed waveform switch signal is turned on, by using the phase estimated from a first known signal and the phase estimated from a second known signal, thereby preventing the received signal from becoming degraded.

Abstract: A synchronizer of a fast frequency hopping spread spectrum receiver includes a correlator and a peak detection circuit for detecting the peak of the output signal of the correlator and outputting a detection signal. A sampler has the output signal of the correlator pass therethrough when the detection signal is outputted from the synchronizer. A code discriminating circuit discriminates the code of the output signal of the sampler. M pieces of frequency synthesizers of the correlator output M pieces of sinusoidal wave signals having the same frequencies as the frequencies of M pieces of carriers, respectively. A delay line of the correlator includes a plurality of delay elements connected with one another in a cascade, and delays the input signal of the correlator by each delay element and converts the input signal into M pieces of parallel input signals having different delay time, respectively. Besides, the delay time of respective delay elements is defined as a chip period.