Abstract: A wireless receiving device removes signals of a redundant portion of each symbol of a transmission signal to extract signals of a data portion. The wireless receiving device linearly approximates, for each symbol, the overall variation in phase rotation of the symbol calculated by using the signals of the data portion to estimate the amount of phase rotation per time unit of the data portion. Subsequently, the wireless receiving device individually corrects each of the signals of the data portion according to the estimated amount of phase rotation per time unit to correct the signals of the data portion in a single symbol and over a plurality of symbols accordingly on a packet-by-packet basis. The signals of the data portion thus corrected are converted to subcarrier signals.

Abstract: A MIMO detector for use in MIMO-OFDM wireless communication that forms a plurality of propagation paths by using a plurality of transmitting and receiving antennas includes: an inverse matrix calculator operating as an inverse matrix calculation unit configured to calculate an inverse matrix of a matrix of the propagation path based on a signal received by a receiver; a detection speed controller operating as an estimation unit configured to estimate a variation in the propagation path over time; and a phase synchronization circuit and a regulator configured to variably control a processing time required to calculate the inverse matrix by the inverse matrix calculator, according to the variation in the propagation path over time estimated by the detection speed controller. The MIMO detector is provided on the side of the receiver of the wireless communication.

Abstract: A MIMO detector for use in MIMO-OFDM wireless communication that forms a plurality of propagation paths by using a plurality of transmitting and receiving antennas includes: an inverse matrix calculator operating as an inverse matrix calculation unit configured to calculate an inverse matrix of a matrix of the propagation path based on a signal received by a receiver; a detection speed controller operating as an estimation unit configured to estimate a variation in the propagation path over time; and a phase synchronization circuit and a regulator configured to variably control a processing time required to calculate the inverse matrix by the inverse matrix calculator, according to the variation in the propagation path over time estimated by the detection speed controller. The MIMO detector is provided on the side of the receiver of the wireless communication.

Abstract: A Fourier transform processor that is used in wireless communication includes: a Fourier transform mechanism including a butterfly unit and configured to perform a Fourier transform on data that is input to the Fourier transform processor; a first memory configured to store the data that is input to the Fourier transform mechanism; a first commutator configured to rearrange the data that is input to the first memory; and a second commutator configured to rearrange the data that is output from the first memory and that is input to the butterfly unit. This configuration allows the size and power consumption of the Fourier transform processor to be reduced.

Abstract: A speech characteristic-amount calculation circuit 31 calculates an amount of speech characteristics of each phrase in input speech. An estimation process likelihood calculation circuit 33 compares the calculated speech characteristic amount of a phrase with speech pattern sequence information of a plurality of phrases stored in a storage unit 34 to select a plurality of candidates having from a higher likelihood value to a lower likelihood value for the phrases. A recognition filtering device 4 determines whether to reject or not reject the extracted candidates based on the likelihood difference ratio between the difference in likelihood values between the first candidate and the second candidate and the difference in likelihood values between the second candidate and the third candidate.