Adv Antest Corporation

Juichi Nakada

Eiji Nishino

Satoshi Koizumi

Hideki Ichikawa

Kenji Nowara

Shinsuke Tajiri

Koji Asami

Makoto Kurosawa

Takahioro Yamaguchi

Differences in outputs from multiple terminals are easily measured. There is provided a signal measuring device for receiving signals to be measured which are generated by modulating frequency-different signals different in frequency from each other, and are respectively output from different output terminals, including a combiner which combines the signals to be measured output from the output terminals, a quadrature demodulation unit which demodulates a result of the combining carried out by the combiner, an FFT unit which represents a result of the demodulation in the frequency domain, and a characteristic measuring unit, where the characteristic measuring unit measures data for respective frequencies of the result of the demodulation, acquires output-terminal-corresponding data, which correspond to the respective output terminals, based on the data, derives characteristics of the respective output terminals based on the output-terminal-corresponding data, and acquires a difference in the characteristics between the output terminals based on the derived result.

Device, method, and program for measuring signal, and recording medium

A phase measurement device measures an output of an amplifier when an input signal having input frequency components is fed to the amplifier, and includes multipliers for orthogonally transforming the output of the amplifier a phase acquisition section for acquiring phases &#x3b8;and &#x3b8;of the input frequency components in the output of the multipliers, and &#x3b8;and &#x3b8;(third distortion), and &#x3b8;and &#x3b8;(fifth distortion) of the distortion components, a match time/phase measurement section for measuring a match time point &#x394;t when &#x3b8;and &#x3b8;match each other and a distortion component phase measurement section for measuring phases &#x3b8;to &#x3b8;at the match time point &#x394;t. The phase acquisition section acquires at least one of &#x3b8;and &#x3b8;, and &#x3b8;and &#x3b8;(with the frequencies higher than those of &#x3b8;and &#x3b8;) or &#x3b8;and &#x3b8;(with the frequencies lower than those of &#x3b8;and &#x3b8;).

Phase measurement device, method, program, and recording medium

A signal power coefficient and a noise power coefficient are calculated for each channel, using parameters which have been optimized up to a small error value by an optimizing means, then using the thus-calculated signal power coefficient and noise power coefficient, there are determined a signal power and a noise power for each channel, and the signal power and the noise power thus determined are displayed on one and same display screen channel by channel.

CDMA signal waveform quality display system, method, and program, and storage medium storing the program

A multiplexed signal quality display system, method, and program, and recorded medium where the program is recorded. The invention measures the quality of a multiplexed signal from a communication device wherein a band width to be used and the number of communication channels capable of being accommodated are determined by a diffusion code length, and channels to be used having the number of communication channels, which are determined by a diffusion code length, are decided in terms of a diffusion code number affixed to the type of the diffusion code, to effect communication while ensuring multi-channel communication lines in one and same band.

Multiplexed signal quality display system, method, and program, and storage medium storing the program

When a signal having two or more frequency components is fed to a circuit to be measured, a phase of the signal output from the circuit to be measured is measured. A phase measurement device measures an output when an input signal having two input frequency components &#x3c9;and &#x3c9;is fed to an amplifier (circuit to be measured). The phase measurement device includes an orthogonal converter that subjects the output of the amplifier to an orthogonal conversion using an average frequency &#x3c9;, which is an average of &#x3c9;and &#x3c9;. A phase acquisitioner acquires phases &#x3b8;and &#x3b8;of the input frequency components in the output of the orthogonal converter and a phase &#x3b8;of a distortion component. A match time/phase measurer measures a match time &#x394;t during which phase &#x3b8;is matched with phase &#x3b8;, and measures phase &#x3b8;(&#x394;t) during that time. A distortion component phase measurer measures phase &#x3b8;(&#x394;t) of the distortion component in the match time &#x394;t. A display then displays &#x3b8;(&#x394;t) and &#x3b8;(&#x394;t).

A measurement data displaying device includes a measurement data recording unit and charge displaying unit. The measurement data recording unit records a measurement subject channel, a spreading code length corresponding to the measurement subject channel and measurement data which is a code domain power or noise component power of the measurement subject channel. The chart displaying unit displays a chart having a constant width, and represents the measurement data in a display area whose position is determined by the measurement subject channel and the spreading code length, and which has a width corresponding to the spreading code length.

Measurement data displaying device, method, and program, and recording medium on which the program is recorded

Since a multiplexed signal quality display system according to the present invention is provided with a memory means which stores measurement results obtained by measuring electric powers of signals present in all of channels within a band used and a display means which specifies a channel where the presence of a signal is predicted and which reads and displays the measured value of the specified channel, it is possible to display the waveform quality of a channel which is determined by desired Walsh code and Walsh code length.

Multiplexed signal quality display, method, and program, and recorded medium where the program is recorded

According to the present invention, the inputted spectrum diffusion signal is orthogonal-transformed ( ), and then, the common mode output Zre and the orthogonal mode output Zim are respectively AD-transformed ( ). Zre and Zim are respectively inputted to series connections of delay units respectively having a sampling period, and the corresponding delayed outputs are complex-multiplied ( ). Each output is N-points-complex-Fast-Fourier-transformed, and the absolute value of the each coefficient is squared. The squared absolute value is two-dimensionally displayed by setting a horizontal axis as a frequency axis and a longitudinal axis as a time axis ( ). Then, a carrier wave frequency error is obtained from the maximum peak of the frequency, and a timing phase is obtained from the time.

Spectrum diffusion signal analyzer and method of analyzing diffusion signal

An input delay correcting system for an interleave type A/D converter is to be provided. Even if sampling clock signals fed to A/D converters and are not exactly shifted a half cycle from each other, a digital signal outputted from an output terminal of an FIR filter becomes a pulse of a tuning exactly shifted a half cycle from the sampling clock signal fed to the A/D converter . A digital signal outputted from, an output terminal of the FIR filter corresponds to a signal resulting from delaying an output of the A/D converter by an integer multiple of the sampling clock signal cycle. Therefore, if the outputs from the output terminals and of the FIR filter are made alternate by a multiplexer , the outputs of the A/D converters and can be exactly shifted a half cycle with respect to the sampling clock signals fed thereto.

Input delay correcting system and method for A/D converter and storage medium

The present invention offers a method and apparatus for measuring the waveform quality of a CDMA signal with increased accuracy. A baseband digital measuring signal Z(k) from a quadrature transform/complementary filter 22 is applied to a demodulating part 25, wherein it is demodulated by a PN code of a pilot signal to detect a bit train and an amplitude a'.sub.i. An ideal signal R.sub.i is generated from the bit train, the amplitude a'.sub.i and the PN code. At the same time, auxiliary data A, B, C, H and I, which are used to solve approximate simultaneous equations for computing parameters that minimize the square of the difference between the ideal signal R.sub.i and the measuring signal Z(k), are generated in an ideal signal/auxiliary data generating part 26. The thus obtained auxiliary data and the measuring signal Z(k) are used to solve the simultaneous equations to estimate the parameters in a parameter estimating part 27. The parameters are optimized by repeatedly correcting the measuring signal Z(k), the ideal signal R.sub.i and the auxiliary data A, B, C, H, I based on-the estimated parameters and estimating the parameters based on the corrected data. When the parameters are optimized, the power coefficient .rho..sub.i is computed using the optimized measuring signal Z(k) and the PN code.

Method and apparatus for measuring waveform quality of CDMA signal

An input quadrature modulation signal which is converted into a digital signal is converted into a complex baseband signal in a converter 7. A rough estimation of parameters of the signal is made in a rough signal correction unit 51. Using the estimates, the complex baseband signal is corrected. Utilizing a data detection of the corrected signal, a reference signal which corresponds to a transmitted signal is formed from the detected data in a generator 52. The reference signal and the corrected signal are used to estimate parameters in a fine parameter estimation unit 23.

Parameter measuring apparatus for digital quadrature modulation signals

GMSK communication device test system

The signal to be measured is converted into digital form and read into a memory 13 using a trigger as the reference, and a signal of a length 1/5 that of the signal to be measured, in the vicinity of the trigger, is orthogonal-transformed (14). A frequency error .omega..sub.1 of the transformed output I.sub.1,Q.sub.1 is estimated (15) and is used to correct the output I.sub.I, Q.sub.I (16). The corrected output I.sub.2,Q.sub.2 is subjected to processing by a receiving filter (17), and the filtered output I.sub.3,Q.sub.3 is synchronized with a PN code to obtain an ideal signal R.sub.I,R.sub.Q and a phase difference .tau..sub.1 is calculated. The signal I.sub.3,Q.sub.3 and the ideal signal R.sub.I,R.sub.Q are used to obtain a frequency error .omega..sub.2 and a phase error .tau..sub.2 of the signal I.sub.3,Q.sub.3. All signals to be measured, stored in the memory 13, are subjected to orthogonal transformation (23) so that the frequency error .omega..sub.1 +.omega..sub.2 and the phase error .tau..sub.1 +.tau..sub.2 are removed, and the transformed output I.sub.5,Q.sub.5 and the signal R.sub.I,R.sub.Q are used to calculate modulation parameters as is the case with the prior art.

Method for measuring modulation parameters of digital

An in-phase component and a quadrature component of a digitized input DQPSK modulated signal are provided from interpolation filters, respectively. An instantaneous amplitude and an instantaneous phase of the input signal for each symbol clock are detected from the in-phase and quadrature components and are fed to adders. At the same time, that one of symbols '0, 0,' '0, 1,' '1, 0' and '1, 1' which corresponds to the instantaneous phase is detected by a symbol detector. An ideal reference signal generating part generates an ideal amplitude component and an ideal phase component corresponding to the detected symbol and provides them to a parameter calculating part. In an I-Q origin offset detecting part, an I-Q origin offset is calculated on the basis of the relationship between a triangle formed by the current detected vector corresponding to an ideal symbol and a vector detected one symbol clock before and a triangle formed by the said two vectors. An amplitude and a phase corresponding to the calculated I-Q origin offset are provided to the adders, respectively, and are corrected with respect to the detected instantaneous amplitude and phase, thereafter being fed to the parameter calculating part 22. In the parameter calculating part, a transmitter gain, and an amplitude variation, offset frequency and phase error per symbol clock are calculated.

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Tokyo, Japan

Juichi Nakada