Abstract: The present invention provides a wireless station capable of increasing the probability that a path diversity effect can be obtained in a case where a plurality of wireless stations transmit packets using a modulation/demodulation scheme with an anti-multipath property. A delay amount determining section (48) randomly selects a delay amount from among a plurality of candidate values. A transmission timing control section (47) determines a transmission start timing, at which to start the packet transmission, to be a timing obtained by delaying a reference timing by the delay amount selected by the delay amount determining section. At the transmission start timing, a modulation section (49) transmits the packet via an RF section (42) and an antenna (41). The difference between the candidate values is greater than or equal to a predetermined delay resolution, and the difference between a maximum candidate value and a minimum candidate value is less than or equal to a predetermined maximum delay.

Abstract: The present invention provides a wireless transmission system in which it is possible to exert a maximum path diversity effect even if the maximum number of effective branches is limited to a small number. A transmission timing control section (23) determines a transmission start timing to be a timing obtained by delaying a reference timing by a predetermined delay amount. A modulation section (21) modulates a signal by a modulation scheme such that an anti-multipath property is exerted when the signal is demodulated on a receiver side, and transmits the modulated signal at the transmission start timing. In a receiving station (12), a demodulation section (33) demodulates the receive signal to obtain receive data.

Abstract: A detected signal 111 contains a preamble portion which includes symbol alternations, followed by a unique word portion, and a data portion. Each time a symbol alternation is detected, a correction value calculation section 102 averages the phase shift in the detected signal 111 for a predetermined length, thereby calculating a correction value 115. The correction value determination section 103 stores a plurality of correction values 115 in a chronological order. When the unique word portion is detected, the correction value determination section 103 retains, as an effective correction value 118, a correction value which is arrived at by going back a predetermined number of correction values among the stored correction values. A phase rotation section 104 corrects the phase of the detected signal 111 by using an effective correction value 118 calculated by the correction value determination section 103.

Abstract: A detected signal 111 contains a preamble portion which includes symbol alternations, followed by a unique word portion, and a data portion. Each time a symbol alternation is detected, a correction value calculation section 102 averages the phase shift in the detected signal 111 for a predetermined length, thereby calculating a correction value 115. The correction value determination section 103 stores a plurality of correction values 115 in a chronological order. When the unique word portion is detected, the correction value determination section 103 retains, as an effective correction value 118, a correction value which is arrived at by going back a predetermined number of correction values among the stored correction values. A phase rotation section 104 corrects the phase of the detected signal 111 by using an effective correction value 118 calculated by the correction value determination section 103.

Abstract: A clock recovery circuit capable of fast and accurate clock phase locking even in the presence of frequency shift and noise. The input signal includes, in order, a preamble with an alternating bit sequence pattern, a unique word and data. A detection unit detects zero crossings and measures the time interval therebetween. A 1-interval judgment unit judges whether an interval signal is within a predetermined range, and a 2-interval judgment unit sums two adjacent interval signals and judges whether the 2-interval signal is within a predetermined range. A control unit controls a zero-crossing signal based on the judgment result and outputs a valid zero-crossing signal if judged in the affirmative. A switching unit switches between outputting the zero-crossing signal and the valid zero-crossing signal as valid phase error information based on a frame reception signal input from a frame detection unit. A clock generation unit uses the valid phase error information in generating a symbol clock.

Abstract: A wireless transmission system capable of performing a multi-station simultaneous transmission of data, that is, simultaneously transmitting data by wireless to a plurality of stations. The wireless transmission system includes a plurality of wireless stations for transmitting/receiving data and it constitutes a system for path diversity by use of a wireless station at the transmitting end, a multipath transmission path, and a wireless station at the receiving end. At least one of the plurality of wireless stations decides, in accordance with a response packet responsive to a multi-station simultaneous transmission request packet transmitted by the wireless station or other stations, a plurality of delay amounts relative to a reference timing during the multi-station simultaneous transmission in the wireless transmission system.

Abstract: A data receiving device is provided enabling a reduction in the time required for extracting a partial band signal, and capable of being easily made in a simple structure as an LSI device without requiring a plurality of analog circuits having the same characteristics. The data receiving device includes: a first sampler for sampling an in-phase signal I(t) at every predetermined sampling period and outputting the sampled in-phase signal; a second sampler for sampling a quadrature signal at every predetermined sampling period and outputting the sampled quadrature signal; a partial band extracting section structured by a complex filter for extracting partial band signals IBr, QBr from frequency components included in the sampled in-phase signal and the sampled quadrature signal; and first and second delay detection operating sections for performing a delay detecting process based on the partial band signals and outputting detection signals.

Abstract: In a mobile communication system in which the same frequency channel f1 is used to perform communication of the same data between a moving mobile station 2 and a plurality of base stations 1a to 1d while sequentially establishing synchronization therebetween, subcarriers assigned to the base stations 1a to 1d are set so as to satisfy the following conditions. 1. The same frequency channel f1 is used for all the base stations. 2. Subcarriers do not overlap between adjacent base stations. 3. Adjacent subcarriers are not used in each subcarrier set. 4. All subcarriers within the frequency channel f1 (subcarriers having closest intervals which can hold an orthogonal relationship) are used.

Abstract: In an OFDM transmission scheme, in order to compensate any frequency response variation in time wise resulted from any distortion in a transmission path, out-of-synchronization with passage of time, frequency drift, and phase shift, and to improve a demodulation characteristic, a PS detector 261 in a receiver receiving an OFDM signal detects a pilot symbol. A PS1 TPFR calculator 62 calculates a frequency response of the transmission path for a first pilot symbol, while a PS2 TPFR calculator 63 calculates that for a second pilot symbol. Thereafter, a compensation vector calculator 64 calculates compensation vectors from the frequency responses of the transmission path for both of the first and second pilot symbols by linear approximation. A frequency response compensator 65 compensates the frequency response variation of subcarriers in a data symbol based on the calculated compensation vectors.

Abstract: In an OFDM transmission scheme, in order to compensate any frequency response variations time wise resulted from any distortion in a transmission path, out-of-synchronization with passage of time, frequency drift, and phase shift, and to improve a demodulation characteristic, a PS detector in a receiver receiving an OFDM signal detects a pilot symbol. A PS1 TPFR calculator calculates a frequency response of the transmission path for a first pilot symbol, while a PS2 TPFR calculators calculates a frequency response of the transmission path for a second pilot symbol for a second pilot symbol. Thereafter, a compensation vector calculator calculates compensation vectors from the frequency responses of the transmission path for both of the first and second pilot symbols by linear approximation. A frequency response compensatory compensates the frequency response variation of subcarriers in a data symbol based on the calculated compensation vectors.

Abstract: An apparatus and method for OFDM demodulation establish symbol synchronization to minimize between-symbol interference even under an environment where multipath occurs. An incoming signal is an OFDM signal including a transmission symbol structured by a valid symbol period and a guard interval, and a predetermined synchronization symbol is included in the OFDM signal for every transmission frame. A correlator calculates how a signal generated by a synchronization symbol generator and the OFDM signal are correlated. A correlation calculator then calculates a correlation therefrom. An integrator integrates the calculated correlation by the guard interval. A timing determination device determines symbol timing from the integrated correlation. An FFT window generator outputs operation timing for Fourier transform from the determined symbol timing.

Abstract: An input of an OFDM signal containing known pilot carriers among given subcarriers is separated into subcarriers through Fourier transform in a fast Fourier transform unit. A data carrier phase error estimating unit obtains an amount of phase correction of each subcarrier on the basis of the pilot carriers in the separated subcarriers. A data carrier phase correcting unit corrects the phase of the separated subcarrier signal on the basis of the amount of phase correction. Thus, the phase errors of the subcarriers can be corrected and the OFDM symbols can be demodulated even if a frequency error and a timing error are occurring between the transmitter and receiver.

Abstract: A detected signal 111 contains a preamble portion which includes symbol alternations, followed by a unique word portion, and a data portion. Each time a symbol alternation is detected, a correction value calculation section 102 averages the phase shift in the detected signal 111 for a predetermined length, thereby calculating a correction value 115. The correction value determination section 103 stores a plurality of correction values 115 in a chronological order. When the unique word portion is detected, the correction value determination section 103 retains, as an effective correction value 118, a correction value which is arrived at by going back a predetermined number of correction values among the stored correction values. A phase rotation section 104 corrects the phase of the detected signal 111 by using an effective correction value 118 calculated by the correction value determination section 103.

Abstract: An object of the present invention is to provide a data receiving device enabling reduction in time required for extracting the partial band signal, and capable of being easily made in a simple structure as an LSI device without requiring a plurality of analog circuits having the same characteristics.

Abstract: An input of an OFDM signal containing known pilot carriers among given subcarriers is separated into subcarriers through Fourier transform in a fast Fourier transform unit. A data carrier phase error estimating unit obtains an amount of phase correction of each subcarrier on the basis of the pilot carriers in the separated subcarriers. A data carrier phase correcting unit corrects the phase of the separated subcarrier signal on the basis of the amount of phase correction. Thus, the phase errors of the subcarriers can be corrected and the OFDM symbols can be demodulated even if a frequency error and a timing error are occurring between the transmitter and receiver.

Abstract: An input of an OFDM signal containing known pilot carriers among given subcarriers is separated into subcarriers through Fourier transform in a fast Fourier transform unit. A data carrier phase error estimating unit obtains an amount of phase correction of each subcarrier on the basis of the pilot carriers in the separated subcarriers. A data carrier phase correcting unit corrects the phase of the separated subcarrier signal on the basis of the amount of phase correction. Thus, the phase errors of the subcarriers can be corrected and the OFDM symbols can be demodulated even if a frequency error and a timing error are occurring between the transmitter and receiver.

Abstract: Hydrosilylation reaction curable organosiloxane compositions containing a scavenger for radicals that participate in the free radical polymerization of styrene monomers, which yield upon cure a silicone elastomers having extended moldlife.

Abstract: An adaptive antenna includes a buffer for storing sample data obtained by sampling a receive signal, an information storage part for storing a plurality of sets of coefficients, an evaluation part for calculating an evaluation value of the result obtained by the coefficient and the sample data, a selection part for selecting two or more sets of coefficients in order of decreasing evaluation, an exchanging part for exchanging a part of coefficients between the selected sets of coefficients to generate a new set of coefficients, a changing part for changing a part of coefficients of the selected sets with random numbers to generate a new sets of coefficients, a reproduction part for reproducing the selected sets of coefficients as they are, and a determination part for outputting the result obtained by the set of coefficients with the highest evaluation value after the information storage part, the evaluation part, the selection part, the exchanging part, the changing part, and the reproduction part repeats res

Abstract: The present invention provides a silicone antifoaming agent composition excellent in the persistence of the foam controlling effect. The silicone antifoaming agent composition comprises a polydiorganosiloxane and silica, which form an antifoaming agent to be improved, and 1 to 200 parts by weight per 100 parts by weight of the sum total of the polydiorganosiloxane plus silica of a lightly crosslinked siloxane having fluidity.

Abstract: Foam control compositions are prepared by reacting a mixture of components which include a polyorganosiloxane fluid bearing one or more hydroxyl and/or hydrocarbonoxy groups, a resinous siloxane or a silicone resin-producing silicon compound, a finely divided filler material and a catalyst to promote the reaction of the listed components. The compositions can optionally contain a polyorganosiloxane fluid which is substantially free of reactive groups and/or a polyorganosiloxane fluid bearing two or more hydroxyl and/or hydrocarbonoxy groups.