Anritsu Corporation

Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Hiroshi Itahara

Yuichi Hagiwara

Takashi Seike

Yoshihide Gotou

A multicarrier transmission apparatus that achieves both power efficiency in a high-frequency amplifier and quality of transmission signal in a radio transmission system in next-generation mobile communications that supports high speed data packet transmission. In the apparatus, adaptive peak limiterperforms adaptive hard limit processing on baseband signals of frequency channels passed through multiplexing sectionstofor users, multicarrier signal generating circuitwith peak suppressing function performs peak limit processing on a synthesized multicarrier signal, hybrid distortion compensating circuitcorrects non-linear distortion due to high-frequency amplifierand the multicarrier signal is transmitted from an antenna (ANT).

Multicarrier transmission method and apparatus

A synchronous follow-up apparatus includes a PLL portion that outputs a first clock signal, and a control loop portion. The control loop portion includes a reference frequency signal generating portion that outputs a reference frequency signal, a clock signal generating portion that generates a second clock signal having the same frequency as a frequency of the first clock signal based on the reference frequency signal generated by the reference frequency signal generating portion, and a frequency control signal generating portion that generates a frequency control signal to change the frequency of the second clock signal based on a frequency difference between the first clock signal and the second clock signal that occurs after a predetermined time and outputs the frequency control signal to the clock signal generating portion.

Synchronous follow-up apparatus and synchronous follow-up method

A power amplifying apparatus includes a distributing unit that divides an input digital signal to a plurality of the input digital signals so as to distribute the input digital signals to a plurality of devices respectively, and a synthesizing unit that synthesizing output signals from the devices to output the synthesized output signal. Each of the devices includes a delay regulating unit that regulates a delay amount of the input digital signal, a digital/analog converting unit that converts the digital signal regulated by the delay regulating unit to an analog signal, and an amplifying unit that amplifies the analog signal to output the amplified analog signal to the synthesizing unit.

Power amplifying apparatus, power combining system and delay measuring method for power combining system

A power amplifying apparatus has: a signal converting section () which converts an input signal of an orthogonal coordinate system to an amplitude signal and phase signal of a polar coordinate system, which then converts the phase signal to an orthogonal-coordinate phase signal of the orthogonal coordinate system, and which outputs the amplitude signal and the orthogonal-coordinate phase signal; a modulating section () which performs orthogonal modulation on the orthogonal-coordinate phase signal, and which outputs the modulated signal to a nonlinear power amplifier (); and a correcting section () which outputs a gain control signal for the nonlinear power amplifier (). The correcting section () has a correction LUT which is produced on the basis of an output signal of the nonlinear power amplifier () and the input signal of the orthogonal coordinate system, and outputs the gain control signal with reference to the correction LUT on the basis of the amplitude signal.

Power amplifying apparatus

A hybrid distortion compensation method and apparatus that greatly improves the capability to compensate for non-linear distortion due to a high frequency power amplifier over a wideband in strict conditions of smaller size and reduced power consumption. An adaptive pre-distortion section () and a feed forward distortion compensation circuit () are connected via a D/A converter (), an A/D converter () and the like, and signals of parts of the feed forward distortion compensation circuit () are taken out using a switch circuit (SW), fed back to a digital signal processing system, and processed using highly accurate digital signal processing in a control-monitoring section (). After an adjustment section () makes characteristics of two input signals of the feed forward distortion compensation circuit () coincide, feed forward distortion compensation is performed. A sequencer () controls the components sequentially.

Hybrid distortion compensation method and hybrid distortion compensation device

A multicarrier transmission apparatus that achieves both power efficiency in a high-frequency amplifier and quality of transmission signal in a radio transmission system in next-generation mobile communications that supports high speed data packet transmission. In the apparatus, adaptive peak limiterperforms adaptive hard limit processing on baseband signals of frequency channels passed through multiplexing sectionstofor users, multicarrier signal generating circuitwith peak suppressing function performs peak limit processing on a synthesized multicarrier signal, hybrid distortion compensating circuitcorrects non-linear distortion due to high-frequency amplifier, and the multicarrier signal is transmitted from an antenna (ANT).

A digital modulation signal measuring device of the present invention is designed to generate a signal string of an ideal base band component after correcting frequency deviation of a base band component included in a digital modulation signal to be measured, detect a noise component included in the digital modulation signal based on this ideal base band component, and output (display) the spectrum of the detected noise component together with the spectrum of the base band component. Therefore, according to the digital modulation signal measuring device of the present invention, it is possible to easily recognize the quality of a noise component included in a digital modulation signal during actual transmission of the digital modulation signal, to guess the cause of generating the noise and to improve the transfer quality at easy.

Digital modulation signal measuring device and method capable of evaluating spectrum of noise component

A cable line quality evaluating method for evaluating a quality of a cable line for transmitting a digital modulation signal in a bidirectional manner comprises the steps of extracting a noise signal of an upstream line from one of a cable line connection point for evaluating a head end of the cable line evaluated in the quantity and the cable line evaluated in the quantity and a connection point between a tap-off and the cable line evaluated in the quality, generating a pseudo random signal, modulating a carrier signal of its predetermined frequency by means of the pseudo random signal, and then outputting the modulated signal as a test carrier, outputting an output signal obtained by adding the noise signal of the upstream line and the test carrier, selectively receiving the signal of its predetermined frequency from the output signal, and modulating the selectively received signal, and comparing the modulated signal with the pseudo random signal in bits, and then measuring a bit error rate.

Method and apparatus for quality evaluation of cable circuit

In a noise sequence generator, a plurality of memories store plural types of noise sequences that are non-correlated with each other, respectively. A noise sequence readout section reads out the noise sequences stored in the plurality of memories so that the code periods are prime numbers of each other. A sequence-adding section adds the noise sequences read out in parallel from the plurality of memories by means of the noise sequence readout section, thereby outputting the addition result as a series of noise sequences. In a CN controller, a setting section sets a value to determine an amplitude of a digital modulation signal row to a register. A multiplying section multiplies the setting value of the register by the to-be-inputted digital modulation signal row. A CN adding section adds a series of noise sequences outputted from the sequence adding section of the noise sequence generator to an output of the multiplying section, and outputs the addition result.

Noise code string generator and CN controller comprising it

A digital communication system modulated signal generation apparatus incorporates a fading simulator for adding fading to a signal to be transmitted to a device to be tested. A baseband signal generation unit generates a digital baseband signal at a predetermined clock rate, and sequentially outputs time information corresponding to the predetermined clock rate. A fading parameter generation unit receives the time information sequentially output from the baseband signal generation unit together with the digital baseband signal, and output a desired fading parameter set in advance in correspondence with the time information. A fading addition operation unit executes a fading addition operation for the digital baseband signal output from the baseband signal generation unit by using the desired fading parameter output from the fading parameter generation unit, and outputs a signal indicating the result. A digital/analog conversion unit D/A-converts the signal output from the fading addition operation unit. A quadrature modulation unit quadrature-modulates the signal converted by the digital/analog conversion unit, and outputs the quadrature-modulated signal as a modulated signal.

Digital communication system modulated signal generation apparatus

In a frequency spectrum analyzing apparatus which utilizes a DFT (discrete Fourier transform) filter bank, and can detect the peak value of the amplitude of an input signal, a time sequence signal generation circuit samples an input signal to convert it into a time sequence signal. A memory stores the time sequence signal. The DFT filter bank receives a time sequence signal read out from the memory by a control device, and performs DFT filter bank processing corresponding to a plurality of desired frequencies while shifting a window function by a predetermined number of sample point units. An absolute value calculation unit calculates absolute values in units of outputs from the DFT filter bank. A peak value detection unit detects peak values in units of outputs from the absolute value calculation unit. A display device displays the frequency spectrum on the basis of these peak values.

Growing community of inventors

Kanagawa, Japan

Hiroshi Itahara