Abstract: A distortion compensating apparatus for compensating for a distortion of a transmission power amplifier. A delay time decision unit calculates the correlation between a transmission signal and a feedback signal fed back from the output side of the transmission power amplifier while varying phase difference between both signals, and decides the total delay time caused in the transmission power amplifier and a feedback loop on the basis of the phase difference in which the correlation is the maximum. A delay unit delays the transmission signal before a distortion compensation processing by the total delay time, and inputs the delayed signal into a distortion compensating apparatus arithmetic unit, which calculates and stores a distortion compensation coefficient on the basis of the transmission signal and the feedback signal fed back from the output side of the transmission power amplifier.

Abstract: In a distortion compensation device which uses distortion compensation coefficients to subject distortion compensation processing to an input signal and supply the result of the distortion compensation processing to a distorting device, calculates the distortion compensation coefficients based on the input signal before distortion compensation and the feedback signal fed back from the output side of the distorting device, and stores the calculated distortion compensation coefficients in association with the input signal, (1) the feedback signal is AD-converted; (2) the AD-converted output is subjected to fast Fourier transform (FFT) processing; (3) the FFT calculation result is used to calculate the value of either the signal-to-noise ratio SNR, or the adjacent channel leakage power ratio ACLR, or the noise level; (4) the delay time occurring in the distorting device and feedback loop is adjusted such that the difference between the above calculated value at the current time and the above calculated value at

Abstract: In an adaptive predistorter type distortion compensating apparatus for calculating a distortion compensating coefficient by using an adaptive algorithm so as to reduce an error between a reference signal and a feedback signal of a circuit which generates a distortion on the basis of the reference signal, and for compensating the distortion by providing the distortion compensating coefficient to the reference signal, a phase adjustment circuit is provided for determining a phase shift value which reduces a phase difference between a reference signal and a feedback signal, for correcting the phase of the reference signal or the feedback signal by the phase shift value, and for calculating the distortion compensating apparatus after the correction.

Abstract: A searcher for a CDMA receiver apparatus includes a correlator obtaining a correlation value between a spreading code sequence and a spreading code sequence within a received signal, and a non-linear processor carrying out a non-linear conversion to convert one of the correlation value and a predetermined value indicative of the correlation value into correlation value information which has a data width smaller than that of the one of the correlation value and the predetermined value. The correlation value information is used to carry out a search process to search for a synchronizing timing with respect to the spreading code sequence within the received signal.

Abstract: An input complex base band signal x(t) is complex-multiplied by a distortion compensation coefficient h(p), quadrature-modulated by a quadrature modulator QMOD, and input into a power amplifier AMP. A part of the output from the power amplifier AMP is input into a band pass filter BPF, the band pass filter BPF extracts an adjacent channel leakage power band, and a power detector detects an adjacent channel leakage power value. A distortion compensation coefficient arithmetic unit GA using a genetic algorithm computes a distortion compensation coefficient based on an adjacent channel leakage power value on an adjacent channel leakage power ratio and an input complex base band signal x(t), and outputs a distortion compensation coefficient h(p) as a function of a power value p of the input complex base band signal.

Abstract: In a distortion compensating apparatus for adaptively compensating a non-linear distortion of a circuit having the non-linear distortion, an adaptive equalizing processor adaptively selects, from among a filter coefficient group preliminarily held in a memory, a filter coefficient which makes an out-of-band power of an output signal reduced to be set in a digital filter.

Abstract: A communication control apparatus installed in a base station or a mobile station in mobile communications system estimates the relative moving speed of an opposing station, and adjusts the values of communication parameters for a searcher, a transmission power control unit, an absolute synchronous detector unit, etc. according to an obtained moving speed.

Abstract: An input complex base band signal x(t) is complex-multiplied by a distortion compensation coefficient h(p), quadrature-modulated by a quadrature modulator QMOD, and input into a power amplifier AMP. A part of the output from the power amplifier AMP is input into a band pass filter BPF, the band pass filter BPF extracts an adjacent channel leakage power band, and a power detector detects an adjacent channel leakage power value. A distortion compensation coefficient arithmetic unit GA using a genetic algorithm computes a distortion compensation coefficient based on an adjacent channel leakage power value or an adjacent channel leakage power ratio and an input complex base band signal x(t), and outputs a distortion compensation coefficient h(p) as a function of a power value p of the input complex base band signal.

Abstract: A distortion compensation apparatus returns a part of an amplified output signal of a power amplifier amplifying a transmission signal, reads a distortion compensation signal from a distortion compensation table, multiplies the transmission signal with the distortion compensation signal thereof, and inputs the signal to the power amplifier. The distortion compensation signal corresponding to a signal calculated based on an error signal that is a difference between the transmission signal and the amplified output signal, the distortion compensation signal from the distortion compensation table and the step size parameter, and to a power of the transmission signal.

Abstract: In a distortion compensating apparatus for adaptively compensating a non-linear distortion of a circuit having the non-linear distortion, an adaptive equalizing processor adaptively selects, from among a filter coefficient group preliminarily held in a memory, a filter coefficient which makes an out-of-band power of an output signal reduced to be set in a digital filter.

Abstract: The invention relates to a spread-signal multiplexing circuit for frequency-multiplexing a plurality of spread signals that were generated in parallel according to the SSMA scheme. An object of the invention is to adapt to various degrees of multiplicity and to keep the SN ratio and the power efficiency high. To this end, a spread-signal multiplexing circuit of the invention comprises an amplitude monitoring part for multiplexing a plurality of spread signals and determining amplitude of a resulting signal in time-series order; a delaying part for delaying the spread signals in parallel by a time that is equal to a propagation delay time of the amplitude monitoring part; and a multiplexing part for generating a multiplexed signal by multiplexing the delayed spread signals while weighting the delayed spread signals in parallel using weights that are smaller as an average value of the determined amplitude is larger.

Abstract: In a radio apparatus which compensates for non-linear distortion of a transmission power amplifier, a distributor feeds back the output signal of the transmission power amplifier, an error-signal estimating arithmetic unit digitally estimates an error signal, which is ascribable to non-linear distortion of the power amplifier, using a transmit signal and feedback signal, the transmit signal and the error signal are DA-converted by separate DA converters, and a combiner combines the output signals of the DA converters and inputs the combined signal to the transmission power amplifier to perform distortion compensation.

Abstract: A distortion compensation apparatus returns a part of an amplified output signal of a power amplifier amplifying a transmission signal, reads a distortion compensation signal from a distortion compensation table, multiplies the transmission signal with the distortion compensation signal thereof, and inputs the signal to the power amplifier. The distortion compensation signal corresponding to a signal calculated based on an error signal that is a difference between the transmission signal and the amplified output signal, the distortion compensation signal from the distortion compensation table and the step size parameter, and to a power of the transmission signal.

Abstract: A parallel operation system of transmission amplifiers enable the parallel running by the two distortion compensation amplifiers using the digital pre-distorter system and to provide a parallel operation system of the transmission amplifiers that makes it possible to switch to respective single running easily. The parallel operation system includes first and second transmission amplifiers which receive common input signals for outputting amplified signals from respective ones; and a coupling unit which combines outputs of the first and second transmission amplifiers, to provide as its output; the first and second transmission amplifiers each having a main amplifier; and a modulation unit disposed on the input side of the main amplifier; wherein the output of one of the modulation units included in the first and second transmission amplifiers is fed in common to the main amplifiers included in the first and second transmission amplifiers.

Abstract: A communication control apparatus installed in a base station or a mobile station in mobile communications system estimates the relative moving speed of an opposing station, and adjusts the values of communication parameters for a searcher, a transmission power control unit, an absolute synchronous detector unit, etc. according to an obtained moving speed.

Abstract: A communication control apparatus installed in a base station or a mobile station in mobile communications system estimates the relative moving speed of an opposing station, and adjusts the values of communication parameters for a searcher, a transmission power control unit, an absolute synchronous detector unit, etc. according to an obtained moving speed.

Abstract: In a CDMA receiver for applying despread processing to direct wave or delayed waves that arrive via each path of multiple paths, applying synchronous detection processing to the despread signals obtained, combining the detection signals of respective paths and discriminating the received data on the basis of the combined signal, (1) a weighting unit provided for every path measures power of delayed received waves that arrive via its own path and, if the reception power is less than a set level (breakpoint level), subjects an output signal to weighting conforming to the reception power; (2) a RAKE combiner combines signals output from the weighting units of the respective paths; and (3) a data discrimination unit discriminates receive data based upon the output signal of the combiner.

Abstract: The present invention provides a transmission device for predistorting a digital signal in order to compensate distortion, then amplifying and transmitting it. A digital input signal is converted to a first analog signal by a first D/A converter. Separately, the digital input signal is also subjected to predistortion. A compensating signal is then generated from the digital input signal and the predistorted signal. The compensating signal generated thereby is converted into a second analog signal by a second D/A converter. The first analog signal and second analog signal are then added, this addition operation giving a compensated analog transmission signal. This analog transmission signal is supplied to the amplifier for amplification, and then transmitted via an antenna.

Abstract: In a transmission power control apparatus for measuring SIR, which is a ratio of a receive signal to an interference signal, and controlling transmission power of a mobile station in such a manner that the measured SIR will agree with a target SIR, a fading detector detects the rate of change in fading, a correction unit corrects the target SIR based upon the rate of change in fading, and a transmission power control command creation unit creates a command for controlling transmission power of the mobile station in such a manner that the measured SIR will agree with the corrected target SIR, and transmits this command.

Abstract: In a radio apparatus which compensates for non-linear distortion of a transmission power amplifier, a distributor feeds back the output signal of the transmission power amplifier, an error-signal estimating arithmetic unit digitally estimates an error signal, which is ascribable to non-linear distortion of the power amplifier, using a transmit signal and feedback signal, the transmit signal and the error signal are DA-converted by separate DA converters, and a combiner combines the output signals of the DA converters and inputs the combined signal to the transmission power amplifier to perform distortion compensation.