Abstract: Wireless devices and techniques providing improved system acquisition in an environment of multiple co-existing technologies over a common frequency band are disclosed. In one aspect, at a remote terminal, a power spectral distribution (PSD) of received signals is sequentially measured in contiguous segments of a frequency band of interest. One or more characteristics of the measured PSD is compared to at least one predetermined metric to identify the presence or absence of at least one technology type of the received signals in frequency locations across the band. A system acquisition operation is performed in accordance with the identification, such as a tailored scan of channels at locations where a desired technology is identified.

Abstract: There are obtained a transmitting apparatus capable of easily notifying information regarding radio waves required for an objective apparatus, a communication apparatus or a receiving apparatus capable of easily setting a frequency required at each place. a communication system or a broadcast receiving system employing the transmitting apparatus, the communication apparatus, and the receiving apparatus; and a control program, a communication method, and a broadcast receiving method to be used in the communication apparatus or the receiving apparatus. The radio wave tower 101 transmits not only radio waves for the television and the radio, but also the radio wave information 104 for communication and for reception of broadcasts by use of the radio wave information transmitting apparatus 102. For example, the portable terminal 106 first receives the radio wave information 104 in a new place and then obtains a center frequency based on the information for communication with the base station 110.

Abstract: An asynchronous delta-sigma modulator is proposed that comprises an input port, a filter, an envelope path, a phase path, an amplifier, and a feedback path that conveys the amplifier output signal to the filter. The envelope path extracts an envelope from the signal provided by the filter and issues an envelope signal. The phase path processes or processes a phase from the signal provided by the filter and issues a phase signal. The amplifier comprises input ports for the envelope signal and the phase signal. The amplifier issues an amplifier output signal based on said envelope signal and said phase signal. The feedback path conveys the amplifier output signal to the filter. The feedback signal contains both amplitude information and phase information. A corresponding method and computer-program products usable for production and operation of the delta-sigma modulator are also disclosed.

Abstract: A receiver supports a single carrier (SC) form of modulation and a multi-carrier form of modulation such as orthogonal frequency division multiplexing (OFDM). Upon receiving a signal, the receiver determines a maximum fluctuation range (MFR) as a function of at least a fourth-order cumulant of a received signal; and classifies a modulation type of the received signal as a function of the determined maximum fluctuation range. After determining the modulation type of the received signal, the receiver switches to that modulation mode to recover data from the received signal.

Abstract: Methods and systems to calibrate I/Q imbalance with digital equalizers to compensate frequency dependent IQ imbalance, weighted summation modules to compensate frequency independent IQ imbalance, switch modules to controllably direct calibration signals through selected components and to a digital compensation calculator and to control tuner phases during calibration. The equalizers and summation modules may provide genetic IQ imbalance compensation. Methods and systems disclosed herein may be implemented with respect to relatively wideband systems having non-linear spectrum responses, and other systems.

Abstract: This invention relates to a demodulating apparatus and a demodulating method for demodulating an input signal more quickly than before when the channels of the input signal are inverted. A correlator 152 calculates a correlation value indicative of the correlation between a known delayed detection sequence made of symbols of correct delayed detection values of a known sequence inserted in the input signal and a received delayed detection sequence obtained through delay detection of the input signal. If the imaginary part of the correlation value is less than zero, a channel control section 132 switches the channels of the input signal before feeding the signal to a frame synchronization circuit 122. This invention can be applied illustratively to a satellite broadcast receiving apparatus.

Abstract: A receiver includes a frequency translation bandpass filter (FTBPF) and an RF receiver section. The RF receiver section includes an amplifier section, a phase information detection module, an amplitude information detection module, and analog to digital conversion (ADC) modules. The FTBPF is operable to filter an inbound radio frequency (RF) signal to produce a filtered inbound RF signal. The amplifier section is operable to amplify the filtered inbound RF signal to produce an amplified inbound RF signal. The phase information detection module, when enabled, is operable to determine phase information from the amplified inbound RF signal. The amplitude information detection module, when enabled, is operable to determine amplitude information from the amplified inbound RF signal. A first one of the ADCs is operable to convert the phase information into digital phase information and a second one of the ADCs is operable to convert the amplitude information into digital amplitude information.

Abstract: A data processing apparatus able to start decoding at a timing earlier than the conventional timing and able to reduce the storage capacity required for a storing means for storing the encoded data until a decoding side decodes the input encoded data in comparison with the conventional storage capacity, which apparatus selects frame data from frame data f(5) having the last decoding order to frame data f(0) having the first decoding order for processing for calculating a delay time min_delay and calculates the delay time min_delay. It calculates the delay time min_delay indicating the delay time from when the decoding side starts to receive input of the frame data to when the data is decoded based on the specified size and the bit rate of the input of the frame data to the decoding side for each of the frame data for processing.

Abstract: Disclosed herein is a demodulation apparatus including: an operation determination block configured to determine whether the demodulation apparatus operates as part of either a first device or a second device with which the demodulation apparatus communicates, the first device being configured to ASK-modulate and transmit data, the second device being configured to load-modulate and transmit data; and first and second demodulation control blocks.

Abstract: The invention is related to an apparatus which includes a first generator configured to generate transfer function values of in-phase and quadrature channels. The apparatus further includes a determiner configured to determine compensation coefficients on the basis of the generated transfer function values of in-phase and quadrature channels. The apparatus further includes a second generator configured to generate compensated frequency domain symbols for at least one frequency pair by using the compensation coefficients.

Abstract: A method and apparatus for reconfiguring a GPS receiver. A device in accordance with the present invention comprises a Radio Frequency (RF) section, the RF section adaptable to receive at least one GPS signal from at least one GPS satellite; and a baseband section, coupled to the RF section, the baseband section comprising at least one correlator, wherein the at least one correlator is adaptable to reacaquire the at least one GPS signal based on a priori knowledge of the at least one GPS signal.

Abstract: A receiver/transmitter and related receiving/method capable of simultaneously receiving/transmitting discontinuous frequency band signal components of an input/output signal are provided. Phase swapping on in-phase/quadrature-phase local oscillation differential signals is applied to frequency down-conversion of the input signal or frequency up-conversion of a baseband signal to be outputted to radio domain, and thereby achieve simultaneously receiving discontinuous frequency bands of the input signal and simultaneously sending different baseband signal components on discontinuous frequency bands of the output signal.

Abstract: A wireless data transmitter including: a data modulator adapted to modulate a data signal based on a frequency signal; and at least one antenna adapted to wirelessly transmit the modulated data signal and the frequency signal independently.

Abstract: In one embodiment, an analog-to-digital converter (ADC) receives a radio frequency (RF) signal and converts the RF signal into a digital signal at an intermediate frequency. The ADC uses a sampling frequency that is a multiple of the intermediate frequency to perform the conversion. A selector receives the digital signal and outputs a combined in phase and quadrature signal at a plurality of sampling points based on the sampling frequency. A filter receives the combined in phase and quadrature signal and outputs a baseband in phase baseband signal and a baseband quadrature baseband signal.

Abstract: Systems (600) and methods (100) for demodulating a Gaussian Filtered Minimum Shift Keyed (GMSK) signal. The GMSK signal is defined in a transmitted symbol domain where each symbol is given by a product of a current data bit and a previous data bit. The GMSK signal is converted from the transmitted symbol domain to a data symbol domain. The conversion is achieved by approximating filtered complex output signals that would be produced by matched filters having filter shapes corresponding to pulses used in terms of a Laurent expansion. Subsequent to the convention of the GMSK signal, a trellis equalization of the GMSK signal is performed exclusively in the data symbol domain based on the terms of the Laurent expansion.

Abstract: A digital demodulating apparatus comprises circuit components constituting a tuner that applies channel select processing to a received signal, and a demodulator that demodulates the signal to which the tuner has applied channel select processing; a power supply unit that supplies power to each circuit component; a reception condition detecting unit that detects a reception condition when the tuner receives the signal; a power adjusting unit that adjusts the power to be supplied to each circuit component by the power supply unit, on the basis of a result of the detection by the reception condition detecting unit; a fading environment estimating unit that estimates a fading environment when the tuner receives the signal; and a power controlling unit that controls the power adjusting unit on the basis of a result of the estimation by the fading environment estimating unit so that the number of times of adjustments of the power by the power adjusting unit per unit time changes in accordance with the variability

Abstract: An object of the present invention is to increase measurement precision for measuring errors of a quadrature demodulator. An error measurement device 10 receives an I signal and a Q signal from a quadrature demodulator 4 for demodulating a signal to be demodulated including multiple carrier signals respectively different from each other in frequency, and measures a gain imbalance which is a ratio of the amplitude of the Q signal to the amplitude of the I signal.

Abstract: To detect phase mismatches between in-phase and quadrature signals of a quadrature demodulator. The phase mismatches can be detected using the signals obtained by removing high frequency components of output of a multiplier by a low pass filter, the output being the product of the in-phase signals of which low frequency components are removed by a first high pass filter by the quadrature signals of which low frequency components are removed by a second high pass filter.

Abstract: A receiving apparatus, a receiving method, and an imaging apparatus and method, adapted to receive high frequency image signals. The apparatus includes two or more receiver channels, each receiver channel including an antenna pattern including plural antenna elements to receive high frequency image signals, a receiving mechanism to process the high frequency image signals received by the antenna elements into baseband signals, an analog-to-digital conversion mechanism to convert the baseband signals from the receiving mechanism into digital signals, a phase shifting mechanism to phase shift the digital signals, and a combining mechanism to combine the phase shifted digital signals from the receiver channels into combined signals.

Abstract: A receiver configured to selectively receive an RF signal from an operating band having a plurality of RF channels. The receiver is configured to upconvert the desired RF channel to an intermediate frequency (IF) greater than the RF channel frequencies. The upconverted RF channel is downconverted to baseband or a low IF. The receiver can perform channel selection by filtering the baseband or low IF signal. The baseband or low IF signal can be upconverted to a programmable output IF.

Abstract: A receiver can be configured to include an RF front end that is configured to downconvert a received signal to a baseband signal or a low Intermediate Frequency (IF) signal. The receiver can downconvert the desired signal from an RF frequency in the presence of numerous interference sources to a baseband or low IF signal for filtering and channel selection. The filtered baseband or low IF signal can be converted to a digital representation. The digital representation of the signal can be upconverted in the digital domain to a programmable IF frequency. The digital IF signal can be converted to an analog IF signal that can be processed by legacy hardware.

Abstract: Multiple symbol noncoherent soft output detectors in accordance with embodiments of the invention are disclosed. In a number of embodiments, the multiple symbol noncoherent soft output detector uses soft metrics based on the Log Likelihood Ratio (LLR) of each symbol to provide information concerning the reliability of each detected symbol. One embodiment of the invention includes a receiver configured to receive and sample a phase modulated input signal, and a multiple symbol noncoherent soft output detector configured to receive the sampled input signal and to generate a soft metric indicative of the reliability of a detected symbol based upon observations over multiple symbols.

Abstract: A receiver receiving a Radio Frequency (RF) signal and generating a baseband signal is provided. An RF module receives the RF signal and down convert the RF signal according to a first oscillation frequency to generate an Intermediate Frequency (IF) signal. An IF module is coupled to the RF module and arranged to receive the IF signal and down convert the IF signal according to a second oscillation frequency to generate the baseband signal. A calibration module is coupled to the RF module and arranged to calculate the IF signal according to a third oscillation frequency to detect an I/Q mismatch, and generate an adjustment signal, accordingly, to calibrate the I/O mismatch.

Abstract: A performance monitor for generating a digital error signal based upon an RF input signal and an amplified RF output signal is provided.

Abstract: A receiver apparatus and method are provided blind amplitude estimation for a received complex signal, wherein the complex signal is analyzed to determine first and second order statistics of real part and imaginary part of the complex signal. Based on a predetermined non-linear function, amplitude scaling information is pre-calculated and used to derive a desired amplitude scaling information for said determined first and second order statistics. Thereby, a low complexity method for blind amplitude estimation for unknown data symbols distorted by an unknown amount of noise can be provided.

Abstract: Disclosed is a method of blind demodulation of signals arising from one or more transmitters, the signals including a mixture of symbols comprising at least one step of separating the transmitters by using the temporal independence of the symbol trains specific to a transmitter and the mutual independence of the transmitters.

Abstract: System(s) and method(s) are provided to transmit simultaneously a first and a second communication channel in a single-carrier waveform format with disparate error rate requirements. First channel and second channel are coded individually to form an alphabet for a first and second constellation. Prior to transmission, bits of information of the first and second channels are modulated with a hierarchical modulation constellation is generated through a combination of a first a second constellation; each constellation is assigned a configurable weight (e.g., a “hierarchic weight”) that is expressed in terms of a configurable energy ratio. The energy ratio determines the resilience of bits associated with the first and second channel. Bit mapping within the first and second constellation provides redundancy to mitigate error rate within each quadrant of the hierarchical constellation.

Abstract: This disclosure relates systems and methods for a high bandwidth modulation and transmission of communication signals.

Abstract: When a satellite broadcasting receiving device 5 is initially set up, a receivable channel is searched for each satellite. In this search, a wider frequency acquisition range than a frequency acquisition range which is generally used is set for a QPSK demodulation IC 15, while the frequency of a PLL 9 is fixed. Then, in the wider frequency acquisition range, an offset is shifted by a frequency step Fstep? by using a function for setting a frequency offset, the function being included in the QPSK demodulation IC 15. Thus, a signal search is carried out throughout a reception frequency range.

Abstract: A coding unit for determining two different types of modulation to be applied to two carrier signals such that each modulated carrier signal represents a data symbol in accordance with a group of modulation points, each modulation point representing a modulation of the first type and a modulation of the second type that can be applied to one of the carrier signals, the coding unit being arranged to associate the data symbol with a first one of the modulation points by applying a first mapping function to that data symbol and associate the data symbol with a second one of the modulation points by applying a second mapping function to that data symbol, the first and second mapping functions being such that they each map two different data symbols to a respective common modulation point; and determine the modulation of the first and second types to be applied to the first carrier signal to be the modulation of the first and second types represented by the first modulation point and the modulation of the first an

Abstract: A radio receiver comprises an input (14) for a modulated radio frequency signal, a frequency down converter (16) coupled to the input, the frequency down converter including quadrature mixers (32,34) for demodulating a received modulated radio frequency signal using a local oscillator signal. An analogue-to-digital converter (54, 56) is coupled to receive demodulated signals from the mixing means. The analogue-to-digital converter, which may comprise a continuous time sigma delta converter, has an input for a sampling clock frequency (f s). A voltage controlled oscillator (38) provides the local oscillator signal and supplies a frequency divider (60, 94) used to provide the sampling clock frequency.

Abstract: Disclosed are a method and apparatus for measurement report for the decision of transmission mode transition that obtain a threshold value of reporting CQI_difference of all frequency sub-bands; measure a CQI value at each CQI reporting frequency sub-band of whole frequency band in each measure time interval; determine a CQI_difference value based on the measured CQI value of each CQI reporting frequency sub-band; and compare the determined CQI_difference value with the threshold value, if a condition is satisfied, then the UE sends the determined CQI_difference value to the BS. After the UE has reported this measurement report to the BS, the BS may choose a more suitable data transmission mode for the UE based on this measurement report to make data transmission more effective.

Abstract: A method for synchronizing a receiver to a received signal begins by down-converting the received signal to a first baseband signal. A coarse frequency offset (CFO) of the first baseband signal is determined and is applied to the down-converting of the received signal to a second baseband signal. A fine frequency offset (FFO) of the second baseband signal is determined. The receiver is synchronized to the received signal using the CFO and the FFO.

Abstract: The present invention aims to efficiently calibrate the characteristics of a pair of reception or transmission low-pass filters by a receiving or transmitting circuit. A semiconductor integrated circuit includes an RF receiver that processes an RF reception signal, an RF transmitter that generates an RF transmission signal and a frequency synthesizer. A reception low-pass filter of the RF receiver suppresses undesired components contained in I and Q baseband reception signals. A transmission low-pass filter of the RF transmitter suppresses noise due to D/A conversion, which is contained in I and Q transmission analog baseband signals. A calibration test signal is supplied to the inputs of the pair of reception or transmission low-pass filters. A difference in phase between the pair of filters is detected by a phase detection unit. A calibration controller calibrates a relative mismatch between the cut-off frequencies of the pair of filters.

Abstract: A decoding device that decodes demodulated data obtained by demodulating a quadrature modulated signal arising from digital modulation of a carrier and detects synchronization, the decoding device includes, a decoder configured to decode first demodulated data that is the demodulated data obtained by demodulating the quadrature modulated signal and is composed of in-phase axis data and quadrature axis data. The decoding device decodes second demodulated data obtained by interchanging the in-phase axis data and the quadrature axis data of the first demodulated data. A synchronization detector is configured to detect a boundary between predetermined information symbol sequences from first decoded data obtained by decoding the first demodulated data and detect the boundary from second decoded data obtained by decoding the second demodulated data. The synchronization detector selects and outputs one of the first decoded data and the second decoded data based on a result of the detection of the boundary.

Abstract: A processing front-end for FM radio signals includes a receiver, a filter, and a mixer. The receiver obtains an FM radio signal including data content centered at a data frequency and programming content. The filter is coupled to the receiver and removes the programming content from the FM radio signal. The mixer accepts the filtered FM radio signal and shifts the center frequency of the data content to a lower frequency than the first frequency. The lower frequency is selected according to a sampling rate available in an analog-to-digital converter present in a subsequent processing stage, typically a low cost digital signal processor.

Abstract: A receiver estimates I/Q imbalance in I and Q input signals using circuitry to separate different frequency components of the I and Q input signals, and estimation circuitry arranged to estimate I/Q imbalance at the different frequency bands. The separating of the bands may be carried out in the frequency domain, and may involve combining corresponding values representing corresponding negative and positive frequency bands, and converting the separated frequency domain representations to a time domain representation before the estimation. The estimated imbalance may be used to correct the I and Q signals at the different frequency bands.

Abstract: A receive station of the present invention despreads a received signal over both long and short despreading periods to determine individual channel estimates over each symbol period of an extended period for multiple pilot signals. As a result, the present invention provides channel estimates sufficient for both slow and fast fading conditions. The receive station determines an average channel estimate for each of the pilot signals over the extended period by despreading the received signal over the extended period using mutually orthogonal extended spreading sequences. The receive station further determines a combined channel estimate for the pilot signals over each symbol period of the extended period by despreading the received signal over each symbol period using a common spreading sequence. Based on the average and combined channel estimates, the receive station determines individual channel estimates for each pilot signal over each symbol period of the extended period.

Abstract: A data communication device includes: an antenna resonance circuit; a detection circuit; an arithmetic processing device; and a first switch. The antenna resonance circuit receives a signal in the ASK (Amplitude Shift Keying) format. The detection circuit demodulates a digital baseband signal based on the reception signal. The arithmetic processing device detects an appearance time of an edge in the demodulated digital baseband signal based on a preamble part of the reception signal. The first switch short-circuits both end of the antenna resonance circuit at first timing in synchronization with the appearance time of the edge.

Abstract: Filter circuit includes Nth-order active filters switching circuit which switches shorting or non-shorting of active filter, and power-supply control circuit which controls such that a power supply of active filter is turned off when switching circuit shorts active filter. A receiver employing filter circuit turns off the power supply of active filter not needed when no interference wave exists within a given range from a desired frequency band. The foregoing structure allows lowering the power consumption of filter circuit.

Abstract: Phase shifting circuitry is provided for phase shifting at least one of first and second quadrature components of a data signal. The circuitry includes a first phase shifter adapted to phase shift, by a first phase angle, the first quadrature component by adding together weighted versions of the first and second quadrature components.

Abstract: A transmit circuit reduces undesired amplitude modulation (AM) in transmit signal pulses by substituting predetermined amplitude information for actual pulse amplitude information during portions of the pulse corresponding to nominally constant amplitudes. For example, GMSK and certain other modulation formats use a desired transmit pulse shape that includes a nominally flat middle portion. An exemplary AM reduction circuit detects generated pulse values corresponding to the nominally constant-amplitude portions of the transmit pulse and substitutes predetermined, preferably constant, amplitude values in their place. As such, the circuit may include a comparator used to detect the pulse values corresponding to variable amplitude portions of the pulse, which it passes through, and to detect those amplitude values corresponding to constant-amplitude portions of the pulse, which it replaces with substituted values. Such operation may include amplitude value filtering, and such operations may be modal, e.g.

Abstract: A receiver is provided for a quadrature-modulated signal, which can be divided into an inphase signal and a quadrature signal. The inphase signal is fed to first and third equalizers, and the quadrature signal is fed to second and fourth equalizers, wherein the first and second equalizers each perform a first equalization of the respective signal. An output of the first equalizer is connected to a second input of the fourth equalizer, which, by means of a second equalization of the quadrature signal, transmits an equalized quadrature signal as a function of the previously fed equalized inphase signal of the first equalizer. An output of the second equalizer is connected to the second input of the third equalizer, which, through a second equalization of the inphase signal, transmits an equalized inphase signal as a function of the previously fed equalized quadrature signal of the second equalizer.

Abstract: A system and method for estimating sample clock frequency offset (?s) in a digital radio mondiale (DRM) system such as, for example, DRM receivers. The system and method includes using a relationship given by the following equation: ? s = linearfit ( angle ? ( P G m P G ? _ ? tr m P G m ? - ? cycle P G ? _ ? tr m ? - ? cycle ) , l ) × N 2 ? ? × cycle × ( N + L ) wherein the PGm is the gain pilot received in the mth symbol and PG—trm is the gain pilot transmitted in the mth symbol, the PGm-cycle is the gain pilot received in (m-cycle)th symbol, the PG—trm-cycle is the second gain pilot transmitted in (m-cycle)th symbol, the l is the index of the sub-carrier associated with the gain pilot, the N is a factor of a sample point number of a useful symbol, the L is a sample point number of a guard interval, and the cycle is the interval of two symbols which are inserted gain pilots at the same sub-carriers (l).

Abstract: In the reception and demodulation of a communication signal with frequency hopping among a plurality of frequency bands, a demodulator is formed by a balance circuit. The demodulator performs frequency conversion by multiplying signals in_a and in_b, which are obtained by converting a received signal into differential signals, by local signals Lo—1a and Lo—1b with a frequency corresponding to a frequency band of the received signal, which are frequency-switched during a guard interval period of the received signal, in synchronization with a symbol of the received signal. Further, two output ends of the demodulator are charged/discharged through capacitors in synchronization with frequency switching of the local signal so that a voltage difference between the two output ends of the demodulator becomes a prescribed level.

Abstract: Disclosed are various embodiments of an input signal combiner. In one embodiment, a receive stage receives a multi-phase waveform and separates the multi-phase waveform into a plurality of waveforms. Analog-to-digital converters convert the plurality of analog waveforms into at least one digital signal. At least one gain stage adjusts an amplitude of each of the digital signals and combines the amplitude adjusted digital signals into at least one gain adjusted combined signal. A signal extraction stage extracts an inbound signal from the at least one gain adjusted combined signal according to a demodulation scheme.

Abstract: A multi-stage frequency offset (FO) estimation and compensation method and its circuit are described. The method includes performing at least a stage of primary-level FO estimation and compensation procedure, and a stage of advance-level FO estimation and compensation procedure. The first stage receives an input carrier signal of a larger FO and outputs a corrected carrier signal with an estimation error within the required estimation range of the next stage, to the next stage. Generated and fed forward stage-by-stage, the corrected carrier signal free of FO may be approached. Besides, since a feed-forward rather than a closed-loop approach is employed, the SNR requirement may be lower. Also, at primary-level, modulation may be first removed so the whole input carrier signal may be used to estimate FO; at advance-level, the periodic PN sequence in the input carrier signal may be utilized to estimate FO, thereby no dedicated training symbols are required.

Abstract: The present invention relates to estimating a direct current (DC) offset of a radio frequency (RF) receiver when an estimated amplitude of a continuous-transmission amplitude-modulated (AM) RF signal is below a first threshold and when the RF receiver is not receiving an RF input signal. The estimated DC offset of the RF receiver may be used to improve RF receiver performance, particularly over temperature and supply voltage variations. Estimating the DC offset of the RF receiver when the estimated instantaneous amplitude of the continuous-transmission AM RF signal is below the first threshold may minimize errors in the estimated DC offset.

Abstract: The present invention relates to a digital receiver for FM signals, in particular to a new demodulator structure and demodulating method, by which according to a first aspect of the invention the usual complex de-rotation process is reduced to a simple addition/subtraction. According to a second aspect of the invention, the requirements for the sampling frequency necessary for processing the demodulator signals are reduced substantially.

Abstract: According to one embodiment, a signal receiving apparatus includes a first setting module, a calculator, a detection module, a generator, and a determination module. The first setting module is configured to set a rising or falling of an arbitrary high pulse as a starting point. The calculator is configured to calculate a sampling period based on intervals between a plurality of high pulses. The detector is configured to set a multiple of the sampling period from the starting point as reference points and to detect positions where the plurality of high pulses are generated from each of the reference points. The generator is configured to generate a histogram for the positions where the plurality of high pulses are generated. The determination module is configured to determine positions obtained by adding a value of a peak in the histogram to each of the reference points as sampling points.