Panasonic Corporation

Panasonic Intellectual Property Corporation of America

Toyota Jidosha Kabushiki Kaisha

Toyota Infotechnology Center Co. Ltd.

Hiroaki Morino

Ayako Horiuchi

Kenichi Miyoshi

Akihiko Nishio

Tomohiro Imai

Kenichi Kuri

Seigo Nakao

Daichi Imamura

Katsuhiko Hiramatsu

Yasuaki Yuda

A wireless communication system enabling multihop communication while maintaining the system throughput and preventing degradation of the user throughput. In the system, a BS (base station) determines the relaying method (whether an RS performs reproduction relay or nonreproduction relay) of the RS (relaying station) and the MCS of multihop communication according to the reception quality (the line quality among an MSthe RS, and the BS) of the pilot for nonreproduction relay, the reception quality (the line quality between the RS and the BS) of the pilotfor reproduction relay, and the line quality (the line quality between the MSand the RS) measured at the RS. The determination result is transmitted as relay information to the RS and to the MS(a mobile station ()) through the RS. The MSencodes and modulates the uplink data with the MCS based on the relay information and transmits the data to the RS. The RS relays the uplink data while selecting nonreproduction relay or reproduction relay according to the relay information.

Base station apparatus and communication method

Integrated circuit

Disclosed is a radio communication device capable of improving the usage efficiency of resources in multi-stage relay to reduce the amount of delay of a relay signal and improving the reception quality of signals by a relay station or a base station. A transmission determining unitdetermines whether to transmit the relay signal and whether to transmit ACK/NACK on the basis of whether there is an error in the relay signal, and on the basis of ACK/NACK received from a one-hop-downstream radio communication device. An MCS determining unitprovided in the transmission determining unitdetermines an MCS for the relay signal. A transmission instruction generated by the transmission determining unitis output to a bufferand an ACK/NACK generating unit. The determined MCS is output to an error correction coding unitand a modulation unit. The ACK/NACK generating unitgenerates ACK when there is no error in the relay signal, and generates NACK when there is an error in the relay signal.

Radio communication device and radio communication system

To prevent relaying wrong information by determining whether a radio signal is to be relayed in accordance with a function of error detection in the radio signal. A relay station apparatus according to an aspect of the invention is a relay station apparatus which relays a radio signal between a transmission station and a reception station, including: a receiver which is configured to receive the radio signal from the transmission station; and a relay determination section which is configured, in accordance with a function of error detection in the radio signal received by the receiver, to determine whether the signal is to be relayed or not, based on a first channel quality indicating a channel quality from the transmission station to the relay station apparatus.

Relay station apparatus and relay method

Provided is a relay transmission method capable of obtaining the diversity effect even when a relay station has detected an error in a relay signal when performing communication between a base station and a mobile station via a relay station. In the relay station used in this method, a decoding unit () performs error-correction-decoding of a systematic bit by performing repeated decoding such as a turbo decoding by using a parity bit and obtains a decoding result formed by a systematic bit after the error-correction-decoding. An error judging unit () judges whether the decoded result has an error by using CRC (Cyclic Redundancy Check). An encoding unit () performs error-correction-encoding of the decoded result and obtains a systematic bit after error-corrected-encoded and a parity bit. A selection unit () selects the decoded result inputted from the decoding unit () or the bit string inputted from the encoding unit () according to the judgment result obtained by the error judging unit () and outputs it to a modulation unit ().

Radio communication apparatus and relay transmission method

Wireless communication system

Provided is a mobile communication system capable of obtaining a diversity effect even when a signal received by a relay station has an error in a corporate relay to which time space encoding is applied. In this mobile communication system, when Shas no error and Shas an error, a relay station () does not perform relay transmission at time t (Null) and relay-transmits S* to a base station at time t+T. That is, in this case, the relay station () relay-transmits at time t+T only Sto be transmitted at time t when no error is contained in either Sor S. Moreover, when Shas an error and Shas no error, the relay station () relay-transmits Sat time t and does not perform relay transmission at time t+T (Null). That is, in this case, the relay station () relay-transmits only Sto be transmitted at time t+T at time t if no error is contained in either Sor S

Radio communication apparatus and radio communication method

A wireless communication method capable of preventing reduction of the throughput. According to this wireless communication method, in a frame (), a relay station () decides that the amount of delay to be &#x394;t2 because the modulation scheme of a relayed signal is 16 QAM, while another relay station () decides that the delay amount be &#x394;t4 because the modulation scheme of a relayed signal is QPSK. The relay station () transmits, at &#x394;t2 of the frame (), the relayed signal, the modulation scheme of which is 16 QAM, to abase station. On the other hand, the relay station () detects, by &#x394;t4, the fact that the relay station () transmitted the relayed signal at &#x394;t2, and estimates, from the detected fact, that the modulation scheme used by the relay station () was 16 QAM. The relay station () then updates its modulation scheme from the initially established modulation scheme of QPSK to the same modulation scheme of 16 QAM as the relay station (), and modulates the relayed signal by use of 16 QAM and then transmits it to the base station.

Wireless communication apparatus and wireless communication method

A wireless communication system enabling multihop communication while maintaining the system throughput and preventing degradation of the user throughput. In the system, a BS (base station) determines the relaying method (whether an RS performs reproduction relay or nonreproduction relay) of the RS (relaying station) and the MCS of multihop communication according to the reception quality (the line quality among an MS, the RS, and the BS) of the pilot for nonreproduction relay, the reception quality (the line quality between the RS and the BS) of the pilotfor reproduction relay, and the line quality (the line quality between the MSand the RS) measured at the RS. The determination result is transmitted as relay information to the RS and to the MS(a mobile station ()) through the RS. The MSencodes and modulates the uplink data with the MCS based on the relay information and transmits the data to the RS. The RS relays the uplink data while selecting nonreproduction relay or reproduction relay according to the relay information.

A mobile station wherein the power consumption can be suppressed. In a frame, this mobile station () transmits, to both a base station () and a relay station (), a multicarrier signal comprising a plurality of subcarriers that have been controlled in transmission power on the basis of reception quality information(Processes () and ()': first transmission). In a frame, the mobile station () transmits, only to the base station (), a multicarrier signal comprising a plurality of subcarriers that have been controlled in transmission power on the basis of reception quality information(Process (): second transmission). In this case, the mobile station () selects subcarriers in which reception qualities indicated by the reception quality informationare lower than a target quality, and the mobile station () then transmits, to the base station (), a multicarrier signal comprising only those subcarriers in which the reception qualities are lower than the target quality.

Mobile station apparatus and wireless communication method

A wireless communication device for performing wireless communications between a plurality of terminals embraced by a multi-hop wireless communication network, includes first communication means for transmitting and receiving neighboring terminal information at a first speed to and from non-neighboring terminals other than neighboring terminals of a self-terminal, and second communication means for transmitting and receiving information other than at least the neighboring terminal information at a second speed higher than the first speed to and from the neighboring terminals to the self-terminal.

Growing community of inventors

Tokyo, Japan

Hiroaki Morino