Abstract: A signal receiving device obtains information data based on a plurality of signals received at a plurality of antennas. The signal receiving device is divided into a first receiving unit and a second receiving unit. The first receiving unit carries out certain part of an entire receiving process, and the second receiving unit carries out the remaining part of the receiving process. The first receiving unit demodulates and synthesizes the received signals and decodes the synthesized signal to recover received information data. The first receiving unit modulates the received information data to obtain a modulation signal and transmits the modulation signal to the second receiving unit via a transmission cable. The second receiving unit recovers the received information data by demodulating the modulation signal received via the transmission cable, and obtains the information data by decoding the recovered information data.

Abstract: The present invention provides a correlator and a demodulation device including, first and second filter sections having different non-overlapping pass-frequency characteristics, first and second delay circuits that delay the signals output from the first and second filter section by one effective OFDM symbol period, first and second complex conjugate circuits that take the complex conjugates of the delayed signals, first and second complex operation sections that compute the complex-multiplies of the signals from the first and second filter sections and the respective signals for the first and second complex conjugate circuits, first and second moving average processing sections that take moving averages of GI lengths, proportion determination circuit that compares the maximum values of the autocorrelations from each of the first and second moving average processing circuits, and selection-combination circuit that selects the autocorrelation having the largest maximum value based on the comparison result.

Abstract: The calculator calculates the remainder of the division of which the dividend is the minimum accumulated value at which a carryover occurs in the ?? modulator and the devisor is a fractional set value, and calculates the quotient and remainder of the division of which the dividend is the devisor of the previous division and the devisor is the remainder of the previous division until the remainder becomes zero. The abnormal noise determiner determines that the fractional set value causes periodic abnormal noise based on the quotients calculated by the calculator using the fractional set value. The fractional setter sets in the ?? modulator the fractional set value changed to the extent that the output frequency of the VCO does not exceed a given value when the abnormal noise determiner determines that the changed fractional set value does not cause periodic abnormal noise.

Abstract: A diversity reception device includes branches, a controller and a combining section. Each branch includes a correlation section that generates a correlation signal that represents a correlation between a received signal and a delayed signal or between the received signal and a reference signal, where the correlation signal level disregarding the received signal level, a time position detector that detects time positions at which the level of the correlation signal is at a peak, a demodulation section that demodulates the received signal, and a multiplication section that multiplies the demodulated signal with a weighting factor. The controller controls the weighting factor on the basis of the respective levels of the correlation signals at the detected time positions. The combining section combines, by adding, the respective demodulated signals of the branches subsequent to the demodulated signal of each branch being multiplied with the weighting factor.

Abstract: Suitable gain control is achieved at low cost. In a receiving apparatus, an RF signal that is amplified by an RF amp is converted to an IF frequency by a frequency conversion unit and amplified by an IF amp, then the output signal from the IF amp that was converted to a digital signal by an ADC is inputted to a digital processing unit. The output from the ADC is then filtered to a desired frequency by a digital filter and inputted to the digital processing unit. In the digital processing unit the signal power before filtering by the digital filter and the signal power after filtering by the digital filter are measured, and the power difference is calculated. Based on the power difference, which indicates the ratio of unnecessary power, the digital processing unit controls the gain ratio of the RF amp and IF amp.

Abstract: A signal receiving device obtains information data based on a plurality of signals received at a plurality of antennas. The signal receiving device is divided into a first receiving unit and a second receiving unit. The first receiving unit carries out certain part of an entire receiving process, and the second receiving unit carries out the remaining part of the receiving process. The first receiving unit demodulates and synthesizes the received signals and decodes the synthesized signal to recover received information data. The first receiving unit modulates the received information data to obtain a modulation signal and transmits the modulation signal to the second receiving unit via a transmission cable. The second receiving unit recovers the received information data by demodulating the modulation signal received via the transmission cable, and obtains the information data by decoding the recovered information data.

Abstract: System and method of data communication and a semiconductor device capable of transmitting information data through a communication interface with a specified response duration without degradation in efficiency of operation. In a first information processing unit, when a first controller issues request signals of predetermined data processing, a first communication interface sends a pseudo response to the first controller in response to one of the request signals and transmits the request signal to a second information processing unit which in turn performs predetermined information processing indicated by the request signal and sends back response data. The first communication interface stores the received response data in memory and reads the response data from memory in response to a request signal issued for the second time onward from the first controller after complete storing of the response data, and then supplies the data to the first controller.

Abstract: An OFDM modulation signal receiving apparatus by which a user can generally grasp a reception state of an OFDM modulation signal and take measures to improve the reception quality thereof. The OFDM modulation signal receiving apparatus comprises: an autocorrelation calculating part that calculates an autocorrelation value of an OFDM modulation signal at predetermined periods; an intra-interval total sum value calculating part that sums up comparison result values obtained by comparing the autocorrelation value with at least one threshold in each predetermined interval to calculate an intra-interval total sum value of each predetermined interval; and a selection storage part that stores a piece of autocorrelation level data according to the intra-interval total sum value in each predetermined interval.

Abstract: An OFDM modulation signal receiving apparatus by which a user can generally grasp a reception state of an OFDM modulation signal and take measures to improve the reception quality thereof. The OFDM modulation signal receiving apparatus includes: a demodulating part that demodulates an OFDM modulation signal to obtain a demodulation signal value on a modulation coordinate for each sub carrier; an intra-interval total sum value calculating part that sums up, for each frequency distribution interval of the sub carriers, comparison result values obtained by comparing the sub carrier signal value to a predetermined determination value to calculate an intra-interval total sum value of each frequency distribution interval; and a selection storage part that stores a piece of noise level data according to the intra-interval total sum value for each frequency distribution interval.

Abstract: The Present invention provides a correlator including, a read-out processing circuit that reads out an OFDM signal in RAM as 2n?1 number of delay OFDM signals that are increased and delayed sequentially with their adjusted read-out timings. Complex conjugate circuits that outputs complex conjugates of the inputted nth to 2n?1th delay OFDM signals. Complex arithmetic circuits that perform complex multiplication to inputted original OFDM signal, the first to n?1th delay OFDM signals, and the output signals from the complex conjugate circuits. Moving average processing circuits take the moving average of the GI length, gain adjustment circuits adjust the gains, an adder circuit adds the outputs of the adjustment circuits, and a filter circuit smoothes the addition result. A control circuit variably controls the delay of the delay OFDM signals, the gains of the gain adjustment circuits, and the band characteristic of the filter circuit.

Abstract: An interference wave detecting apparatus includes a first Fourier transformer for frequency-converting a received signal; an extractor for extracting a known information signal from the frequency-converted received signal; an interpolator for performing interpolation to the known information signal in frequency domain, generating a first transmission path estimation signal as a frequency-domain information signal; an inverse Fourier transformer for inverse-Fourier-transforming the known information signal, generating a time-domain information signal; a waveform shaping section for shaping a waveform of the time-domain information signal; a second Fourier transformer for Fourier-transforming the shaped time-domain information signal, generating a second transmission path estimation signal as a frequency-domain information signal; and a comparing-computing section for comparing the first and second transmission path estimation signals, generating an interference wave detection result which indicates a ratio of

Abstract: There is provided a channel estimating method of performing frequency conversion by a first fast Fourier transformation on a reception signal and extracting a desired signal after demodulating the reception signal, and deriving electrical energy against time delay of a channel by inverse fast Fourier transformation of the extracted result, wherein: values of a low pass filter, having an output from oversampling the input to the first fast Fourier transformation, are thinned by a plurality of thinning circuits with the same synchronization and different discrete times, and based on the outputs of the plurality of thinning circuits, the electrical energy against time delay related to the reception signal arrival time position is derived by respectively performing the first fast Fourier transformation and the inverse fast Fourier transformation.

Abstract: An FSK signal modulator is provided in a transmitter which receives desired information to be transmitted on its input and which modulates the information to be transmitted to transmit a binary FSK signal. A counter counts a value of addition with the value of addition modified in accordance with a predetermined rule, depending on the value specified by the information to be transmitted, and for holding the counted value . The count value is determined by a threshold value decision circuit with respect to a threshold value. The result from the decision is output in the form of binary FSK signal. An FSK signal modulator will be provided which is simplified in circuit constitution.

Abstract: The present invention provides an FFT window spread generating method used in the modulation of an OFDM system. When OFDM-modulated received signals each having a time length greater than or equal to an effective symbol length are demodulated by FFT processing using a spread FFT window, the spread FFT window makes use of received signals each having the time length greater than or equal to the effective symbol length. Spreading windows spread before and/or after the effective symbol length are provided. Received signals lying within the spreading windows are added to their corresponding received signals lying within the effective symbol length and different in time position by the effective symbol length, and the amplitudes of the added received signals are reduced to half respectively, thereby generating the spread FFT window.

Abstract: The present invention provides a correlator and a demodulation device including, first and second filter sections having different non-overlapping pass-frequency characteristics, first and second delay circuits that delay the signals output from the first and second filter section by one effective OFDM symbol period, first and second complex conjugate circuits that take the complex conjugates of the delayed signals, first and second complex operation sections that compute the complex-multiplies of the signals from the first and second filter sections and the respective signals for the first and second complex conjugate circuits, first and second moving average processing sections that take moving averages of GI lengths, proportion determination circuit that compares the maximum values of the autocorrelations from each of the first and second moving average processing circuits, and selection-combination circuit that selects the autocorrelation having the largest maximum value based on the comparison result.

Abstract: A diversity reception device includes branches, a controller and a combining section. Each branch includes a correlation section that generates a correlation signal that represents a correlation between a received signal and a delayed signal or between the received signal and a reference signal, where the correlation signal level disregarding the received signal level, a time position detector that detects time positions at which the level of the correlation signal is at a peak, a demodulation section that demodulates the received signal, and a multiplication section that multiplies the demodulated signal with a weighting factor. The controller controls the weighting factor on the basis of the respective levels of the correlation signals at the detected time positions. The combining section combines, by adding, the respective demodulated signals of the branches subsequent to the demodulated signal of each branch being multiplied with the weighting factor.

Abstract: The Present invention provides a correlator including, a read-out processing circuit that reads out an OFDM signal in RAM as 2n?1 number of delay OFDM signals that are increased and delayed sequentially with their adjusted read-out timings. Complex conjugate circuits that outputs complex conjugates of the inputted nth to 2n?1th delay OFDM signals. Complex arithmetic circuits that perform complex multiplication to inputted original OFDM signal, the first to n?1th delay OFDM signals, and the output signals from the complex conjugate circuits. Moving average processing circuits take the moving average of the GI length, gain adjustment circuits adjust the gains, an adder circuit adds the outputs of the adjustment circuits, and a filter circuit smoothes the addition result. A control circuit variably controls the delay of the delay OFDM signals, the gains of the gain adjustment circuits, and the band characteristic of the filter circuit.

Abstract: A receiving apparatus may achieve optimal RF and IF gain control while suppressing saturated amplification due to interference. The receiving apparatus includes an RF variable gain Amp that amplifies a received RF signal, a mixer that converts an output signal of the RF variable gain Amp into an IF signal, an IF variable gain Amp that amplifies the IF signal, a demodulator that demodulates an output signal of the IF variable gain Amp, and an AGC circuit. The AGC circuit sets a period of gain control for the RF variable gain Amp to be shorter than a period of gain control for the IF variable gain Amp when gains of the RF variable gain Amp and the IF variable gain Amp are controlled based on the output signal of the IF variable gain Amp.

Abstract: A detector of patterns corresponding to pilot symbols is capable of detecting patterns of SP symbols promptly without using a TMCC signal. The SP location detector includes a multiplier which multiplies received signals generated by demodulating OFDM modulation signals in which pilot symbols are dispersively disposed in accordance with four types of patterns and which are transmitted periodically by a pseudo-random number bit sequence, four arithmetic circuits which are respectively provided corresponding to the four types of patterns and which respectively extract pilot symbols corresponding to respective patterns from results of multiplication by the multiplier and calculate sums of phase differences between the extracted pilot symbols, followed by outputting absolute values thereof, and a pattern detection circuit which detects the corresponding arithmetic circuit maximum in the calculated absolute value from within the four arithmetic circuits.

Abstract: Suitable gain control is achieved at low cost. In a receiving apparatus, an RF signal that is amplified by an RF amp is converted to an IF frequency by a frequency conversion unit and amplified by an IF amp, then the output signal from the IF amp that was converted to a digital signal by an ADC is inputted to a digital processing unit. The output from the ADC is then filtered to a desired frequency by a digital filter and inputted to the digital processing unit. In the digital processing unit the signal power before filtering by the digital filter and the signal power after filtering by the digital filter are measured, and the power difference is calculated. Based on the power difference, which indicates the ratio of unnecessary power, the digital processing unit controls the gain ratio of the RF amp and IF amp.