Abstract: An information processing apparatus executes processing based on received information conforming to IEEE 802.11n, and includes: an incident angle measuring unit acquiring a received signal and measuring an incident angle of the received signal's radio wave; a reliability estimating unit estimating reliability of a measurement result of the incident angle, by analyzing a state of occurrence of fading using a relationship between frequency and signal intensity of the received signal; and a processing unit executing or controlling processing utilizing the measurement result of the incident angle. The processing unit executes or controls the processing utilizing the measurement result of the incident angle if the estimating unit judges that the reliability of the measurement result of the incident angle is high, and prohibits the processing utilizing the measurement result of the incident angle if the estimating unit judges that the reliability of the measurement result of the incident angle is low.

Abstract: This application discloses, among other things, a receiving device including channel signal output unit for sampling a received signal at a sampling rate switched one of in a predetermined range and between a plurality of values and outputting a channel signal, control unit for controlling the sampling rate in the channel signal output unit, response estimation unit for estimating a response based on the channel signal output by the channel signal output unit, evaluation unit for evaluating a reception characteristic based on an estimation result of the response by the response estimation unit, and determination unit for determining the sampling rate in the channel signal output unit based on an evaluation of the reception characteristic at a plurality of sampling rates by the evaluation unit.

Abstract: A receiver apparatus is disclosed. The receiver apparatus includes a plurality of signal receiving devices and a plurality of channel signal outputting devices for sampling signals received by the signal receiving devices at sampling rates switched within a predetermined range or between multiple values and outputting channel signals. The receiver apparatus also includes control devices for controlling the sampling rates in the channel signal outputting devices. The receiver apparatus also includes response estimating devices for estimating responses on the basis of the channel signals output from the channel signal outputting devices. The receiver apparatus also includes evaluating devices for evaluating reception characteristics on the basis of the responses estimated by the response estimating devices.

Abstract: A communication system for pulse based communication using a sequence acquisition system using the correlation method in UWB communications which generates a pulse detection signal differing in phase by exactly a predetermined period (?) from the transmission information of a pulse signal of a predetermined period at the transmission side and reception side, uses the pulse detection signal to establish synchronization at the reception side, then generates transmission information at the reception side by making its phase different by exactly a predetermined time from the synchronized pulse detection signal so as to establish synchronization between the reception signal and the transmission information, whereby it is possible to enable synchronization acquisition and shorten the synchronization acquisition time without complicating the hardware and even without the presence of information in the transmission signal.

Abstract: A wireless communication device is provided. The wireless communication device executes digital processing for a received UWB signal with use of an A/D converter having an adequate sample rate and resolution, and thus can obtain precise reception timing information. Since the sample rate of an A/D converted output is high, a timing detection circuit is formed of two-stage matched filters. The former-stage chip matched filter calculates the correlation between an input signal and a template signal. When a correct transmission pulse signal has arrived, the chip matched filter outputs to a frame matched filter an indication as to the presence of a pulse and reception timing. The latter-stage frame matched filter calculates the correlation value between a received frame signal and a spreading code to thereby determine whether the received frame is correct or incorrect, and adequately changes a threshold value of the chip matched filter.

Abstract: A synchronization acquisition method for impulse-based communication including synchronizing received information with a first pulse signal having the same period as the transmit information transmitted from the transmitting end. When the correlation between the received information and an unmodulated second pulse signal exceeds a predetermined threshold, the correlation value is stored together with the reception time in memory. The stored values are sequentially updated, wherein synchronization between the received signal and the first pulse signal is established by determining the generation timing of the first pulse signal by using the time stored in the memory.

Abstract: An information processing device for processing reception signals converted into digital signals, includes: a first conversion unit for executing sampling rate conversion of each of the digital signals to be computed with each tap coefficient of a K'th-order FIR filter; a filter computing unit for executing computation processing of the K'th order FIR filter on K digital signals each of which have been subjected to sampling rate conversion by the first conversion unit; and a control unit for controlling sampling rate conversion of the digital signals by the first conversion unit, and the computation processing of the K'th order FIR filter by the filter computing unit.

Abstract: An Orthogonal Frequency Division Multiplexing (OFDM) receiving apparatus having a sub-carrier selectively combining mode and an antenna selecting mode. The sub-carrier selectively combining mode is configured to selectively combine signals for each sub-carrier. The antenna selecting mode is configured to select a receiving antenna. The OFDM receiving apparatus operates in a proper operation mode based on a communication environment. As a result, in a poor communication environment, signals are selectively combined for each sub-carrier. However, in a relatively satisfactory communication environment, unnecessarily operation of an RF and IF circuit, an A/D converter, and a DDT connected to each receiving antenna may be avoided.

Abstract: A receiver supporting a plurality of radio communication systems having different specifications includes a setting unit, a clock generation circuit, a voltage-current conversion amplifier, a switch, integrators, an AD conversion circuit, and a feedback circuit. The setting unit sets a value suitable for a carrier frequency used in one selected radio communication system. The clock generation circuit generates a first clock having a first frequency and a second clock having a second frequency. The conversion amplifier converts an input voltage signal into a current signal. The switch switches between connection and disconnection modes in accordance with the first clock to output the current signal. Each integrator operates in accordance with the second clock and includes two or more switched capacitor circuits and an operational amplifier. The AD conversion circuit converts a signal supplied from the preceding integrator into digital form. The feedback circuit operates in accordance with the second clock.

Abstract: A receiver apparatus includes a plurality of signal receiving means; a plurality of channel signal outputting means for sampling signals received by the plurality of signal receiving means at sampling rates switched within a predetermined range or between multiple values and outputting channel signals; control means for controlling the sampling rates in the plurality of channel signal outputting means; response estimating means for estimating responses on the basis of the channel signals output from the plurality of channel signal outputting means; evaluating means for evaluating reception characteristics on the basis of the responses estimated by the response estimating means; and determining means for determining the sampling rates in the plurality of channel signal outputting means on the basis of the reception characteristics at the multiple sampling rates evaluated by the evaluating means.

Abstract: A wireless communication apparatus for receiving a packet formed of a signal modulated by OFDM includes the following elements. A band-pass filter extracts an OFDM signal of a desired band. A low-noise amplifier having a gain controlled according to a received-signal intensity amplifies the desired OFDM signal. A frequency converter down-converts the amplified OFDM signal into a baseband signal. An analog-digital converter converts the baseband signal into a digital signal. A first high-pass filter removes a DC offset from the baseband signal corresponding to a predetermined preamble portion of the packet. A frequency-offset estimator estimates a frequency offset from the sample signals constituting the baseband signal from which the DC offset has been removed by the first high-pass filter. A frequency-offset corrector removes the estimated frequency offset from the baseband signal.

Abstract: An information processing apparatus executes processing based on received information conforming to IEEE 802.11n, and includes: an incident angle measuring unit acquiring a received signal and measuring an incident angle of the received signal's radio wave; a reliability estimating unit estimating reliability of a measurement result of the incident angle, by analyzing a state of occurrence of fading using a relationship between frequency and signal intensity of the received signal; and a processing unit executing or controlling processing utilizing the measurement result of the incident angle. The processing unit executes or controls the processing utilizing the measurement result of the incident angle if the estimating unit judges that the reliability of the measurement result of the incident angle is high, and prohibits the processing utilizing the measurement result of the incident angle if the estimating unit judges that the reliability of the measurement result of the incident angle is low.

Abstract: A receiving device including channel signal output means for sampling a received signal at a sampling rate switched one of in a predetermined range and between a plurality of values and outputting a channel signal, control means for controlling the sampling rate in the channel signal output means, response estimation means for estimating a response based on the channel signal output by the channel signal output means, evaluation means for evaluating a reception characteristic based on an estimation result of the response by the response estimation means, and determination means for determining the sampling rate in the channel signal output means based on an evaluation of the reception characteristic at a plurality of sampling rates by the evaluation means.

Abstract: A symbol synchronization device that enables effective symbol synchronization establishment and synchronization holding for an arbitrary spread code sequence.

Abstract: The present invention provides a UWB transmitter and receiver, the transmission rate of which is increased, and the SN ratio of which is improved. By investigating the polarity of an echo at ½ position of the chip period Tc, the chip period is shortened to Tc/2 where the polarity of the echo is the same and a pulse signal of the same polarity is continued, whereby it becomes possible to increase the transmission rate. Because the echo and the pulse signal are caused to overlap each other, the SN ratio can be improved.

Abstract: A wireless communication device is provided. The wireless communication device executes digital processing for a received UWB signal with use of an A/D converter having an adequate sample rate and resolution, and thus can obtain precise reception timing information. Since the sample rate of an A/D converted output is high, a timing detection circuit is formed of two-stage matched filters. The former-stage chip matched filter calculates the correlation between an input signal and a template signal. When a correct transmission pulse signal has arrived, the chip matched filter outputs to a frame matched filter an indication as to the presence of a pulse and reception timing. The latter-stage frame matched filter calculates the correlation value between a received frame signal and a spreading code to thereby determine whether the received frame is correct or incorrect, and adequately changes a threshold value of the chip matched filter.

Abstract: To provide a synchronization acquisition method, for impulse-based communication, that can easily accomplish synchronization acquisition even in a multipath environment, and that eliminates the need to repeat synchronization acquisition even when transmit information changes, the synchronization acquisition method being implemented using: a code synchronizing correlator (21) which synchronizes received information with a first pulse signal having the same period as the transmit information transmitted from the transmitting end; a memory (211) in which, when the value representing the correlation between the received information and an unmodulated second pulse signal having the same period as the first pulse signal exceeds a predetermined threshold, the correlation value is stored together with its reception time; and a timing detecting correlator (22) which sequentially updates the contents of the memory with a new correlation value and its generation time when the new correlation value exceeds the correlatio

Abstract: A symbol synchronization device that enables effective symbol synchronization establishment and synchronization holding for an arbitrary spread code sequence.

Abstract: A communication system for pulse based communication using a sequence acquisition system using the correlation method in UWB communications which generates a pulse detection signal differing in phase by exactly a predetermined period (?) from the transmission information of a pulse signal of a predetermined period at the transmission side and reception side, uses the pulse detection signal to establish synchronization at the reception side, then generates transmission information at the reception side by making its phase different by exactly a predetermined time from the synchronized pulse detection signal so as to establish synchronization between the reception signal and the transmission information, whereby it is possible to enable synchronization acquisition and shorten the synchronization acquisition time without complicating the hardware and even without the presence of information in the transmission signal.

Abstract: A receiver includes a phased array antenna and a demodulator. The phased array antenna includes first and second antenna elements and a phase shifter for shifting the phase of a signal received by the first antenna element by a predetermined amount. The demodulator includes a first junction circuit which receives a local signal and a signal output from the phase shifter and which generates a plurality of signals having a phase difference; a second junction circuit which receives a local signal and a signal output from the second antenna element and which generates a plurality of signals having a phase difference; signal combiners for combining corresponding signals output from the two junction circuits; power detectors for detecting the signal levels of the output signals of the signal combiners; and a converter for converting the outputs signals of the power detectors so as to obtain IQ signals.