Kddi Corporation

Yasuyuki Hatakawa

Satoshi Konishi

Toshinori Suzuki

Noriaki Miyazaki

Tadayuki Fukuhara

Tomoko Matsumoto

Koichiro Kitagawa

Riichirou Nagareda

A wireless communication terminal includes a base station communication part which communicates with a base station; an interterminal communication part which communicates with another wireless communication part; a communication failure detector which detects a communication failure with a first connected base station serving as a base station connected thereto; and a communication resume processor which carries out an interterminal communication with another wireless communication terminal so as to communicate with a second connected base station, connected to another wireless communication terminal, via another wireless communication terminal when a communication failure is detected with the first connected base station, thus carrying out a process of resuming a communication upon detecting the communication failure.

Apparatus and method of resuming wireless communication via interterminal communication between wireless communication terminals

A channel information compressing apparatus of the present invention includes a DCT part that performs discrete cosine transform on channel information (CSI) representing the state of a communication channel, and an information compressor that compresses high frequency components of information included in discrete cosine transform data which is produced by way of discrete cosine transform, thus compressing information while maintaining a good accuracy of channel information.

Channel information compressing apparatus adapted to a MIMO system and method

A channel state information compressing apparatus includes a time-to-frequency region converter that converts a region for channel state information which indicates a state of each communication channel from a time region to a frequency region; and an adaptive selector that selects each frequency component to be included in compressed data based on electric power of the frequency component from among frequency region data obtained by the time-to-frequency region converter. The channel state information compressing apparatus outputs the compressed data consisting of each selected frequency component, and information for identifying each frequency component which forms the compressed data.

Channel state information compressing apparatus and method, channel state information expanding apparatus and method, computer programs, receiver, and transmitter

A receiver receives a signal from a transmitter via communication channels, informs the transmitter of channel state information, and includes a channel correlation value computation unit that computes a correlation value assigned to each channel state information combination; a conversion input data generation unit that determines a channel state information combination having a relatively large correlation based on the correlation value, to be conversion input data; a time-to-frequency region conversion unit that converts the region of the conversion input data from a time region to a frequency region; an information compressing unit that compresses information of a frequency component included in the conversion input data obtained by the time-to-frequency region conversion unit; and a transmitting unit that sends the transmitter, information-compressed data obtained by the information compressing unit and information used for isolating the channel state information items included in the conversion input data.

Receiver, channel state information compressing method, and computer program

In a digital signal transmission method according to the present invention, when Nis the number of code multiplexes of a first transmit block including an information bit and part of a parity bit, and Nis the number of code multiplexes of a subsequent transmit block including the remaining parity bit, a spread multiplexerperforms spread multiplexing of each block in a relationship of N&#x3e;N

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Fujimino, Japan

Yasuyuki Hatakawa