National Institute of Information and Communications Technology, Incorporated

National Institute of Information and Communications Technology, Incorporated Administrative Agency

Ryuhei Funada

Hiroshi Harada

Ryota Kimura

Fumihide Kojima

Keiichi Mizutani

Chin-Sean Sum

In order to suppress out-of-band radiation within a range of a spectrum mask regulation without reducing transmission signal power or the like even when a wireless communication is performed in a white space by using OFDM or the like, the present invention is characterized by including an RF circuit characteristic analysis unit, a multipath delay detection unit, a digital filter setting unit, and a transmission power setting unit and further including: a windowing function/windowing duration selection unit configured to select a windowing function and a windowing duration based on the analysis result by the RF circuit characteristic analysis unit, the detection result by the multipath delay detection unit, and the setting by the digital filter setting unit and the transmission power setting unit; a guard interval duration selection unit configured to select a guard interval duration; and a transmission power selection unit configured to select transmission power.

Wireless transmitter, wireless receiver, wireless transmission method, and wireless reception method

Where two or more wireless communication networks having mutually different physical layers coexist, and wireless communication is performed between a plurality of devices and a coordinator in each one of the wireless communication networks, the coordinator of one wireless communication network generates coexistence notification frame data to notify coordinators of the other wireless communication networks of existence of the coordinator. This first coordinator encodes the generated coexistence notification frame data, inserts source data so as to be set as FEC data, modulates the FEC data through a Gaussian frequency shifting keying system (GFSK) so as to be set as a GFSK modulated wave signal, and transmits the GFSK modulated wave signal to the coordinators of the other wireless communication networks.

Wireless communication system, and interference preventing method

Signal decoding apparatus, signal decoding method, program, and information record medium are provided and can accomplish not only high-speed and high-capacity communication, but high-accuracy decoding. An initial channel estimation sectionestimates an initial channel with a pilot symbol added at the beginning of each packet. After a replica of a transmission symbol is generated, for a reception signal vector, CCI components for L transmission antennas are generated. A CCI cancellerremoves the CCI components from the reception signal vector. After the reception symbol vector from which the CCI components had been removed has been obtained, a division deviceobtains an instantaneous estimation value. An update condition determination sectiondetects deterioration of a channel response accuracy based on a threshold value. An instantaneous estimation value whose SNR has been determined to be insufficient is discarded. An averaging circuitoutputs a channel response estimation matrix at time t+1 obtained by an averaging process and supplies the matrix to a symbol decoding section

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Tokyo, Japan

Ryuhei Funada