Abstract: A wireless communication method capable of preventing reduction of the throughput. According to this wireless communication method, in a frame (2), a relay station (1) decides that the amount of delay to be ?t2 because the modulation scheme of a relayed signal is 16 QAM, while another relay station (2) decides that the delay amount be ?t4 because the modulation scheme of a relayed signal is QPSK. The relay station (1) transmits, at ?t2 of the frame (2), the relayed signal, the modulation scheme of which is 16 QAM, to abase station. On the other hand, the relay station (2) detects, by ?t4, the fact that the relay station (1) transmitted the relayed signal at ?t2, and estimates, from the detected fact, that the modulation scheme used by the relay station (1) was 16 QAM.

Abstract: A mobile station wherein the power consumption can be suppressed. In a frame 3, this mobile station (100) transmits, to both a base station (200) and a relay station (150), a multicarrier signal comprising a plurality of subcarriers that have been controlled in transmission power on the basis of reception quality information 1 (Processes (3) and (3)?: first transmission). In a frame 4, the mobile station (100) transmits, only to the base station (200), a multicarrier signal comprising a plurality of subcarriers that have been controlled in transmission power on the basis of reception quality information 2 (Process (5): second transmission). In this case, the mobile station (100) selects subcarriers in which reception qualities indicated by the reception quality information 2 are lower than a target quality, and the mobile station (100) then transmits, to the base station (200), a multicarrier signal comprising only those subcarriers in which the reception qualities are lower than the target quality.

Abstract: 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 MS2, 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 pilot 2 for reproduction relay, and the line quality (the line quality between the MS2 and the RS) measured at the RS. The determination result is transmitted as relay information to the RS and to the MS2 (a mobile station (2)) through the RS. The MS2 encodes and modulates the uplink data with the MCS based on the relay information and transmits the data to the RS.

Abstract: A mobile station wherein the power consumption can be suppressed. In a frame 3, this mobile station (100) transmits, to both a base station (200) and a relay station (150), a multicarrier signal comprising a plurality of subcarriers that have been controlled in transmission power on the basis of reception quality information 1 (Processes (3) and (3)?: first transmission). In a frame 4, the mobile station (100) transmits, only to the base station (200), a multicarrier signal comprising a plurality of subcarriers that have been controlled in transmission power on the basis of reception quality information 2 (Process (5): second transmission). In this case, the mobile station (100) selects subcarriers in which reception qualities indicated by the reception quality information 2 are lower than a target quality, and the mobile station (100) then transmits, to the base station (200), a multicarrier signal comprising only those subcarriers in which the reception qualities are lower than the target quality.

Abstract: A relay transmission method for communication between a base station and a mobile station via a relay station while producing a diversity effect even if the relay station detects an error in the relay signal. A decoding section (104) of the relay station used in this method performs error-correction decoding of a systematic bit by using a parity bit by repetition decoding such as turbo decoding and acquires the results of the decoding composed of the systematic bit having undergone the error-correction decoding. An error judging section (105) judges whether or not any error is present in the decoding results. Coding section (106) performs error-correction coding of the decoding results and acquires the error-correction coded systematic bit and parity bit.

Abstract: A wireless communication method capable of preventing reduction of the throughput. According to this wireless communication method, in a frame (2), a relay station (1) decides that the amount of delay to be ?t2 because the modulation scheme of a relayed signal is 16 QAM, while another relay station (2) decides that the delay amount be ?t4 because the modulation scheme of a relayed signal is QPSK. The relay station (1) transmits, at ?t2 of the frame (2), the relayed signal, the modulation scheme of which is 16 QAM, to abase station. On the other hand, the relay station (2) detects, by ?t4, the fact that the relay station (1) transmitted the relayed signal at ?t2, and estimates, from the detected fact, that the modulation scheme used by the relay station (1) was 16 QAM.

Abstract: 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 MS2, 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 pilot 2 for reproduction relay, and the line quality (the line quality between the MS2 and the RS) measured at the RS. The determination result is transmitted as relay information to the RS and to the MS2 (a mobile station (2)) through the RS. The MS2 encodes and modulates the uplink data with the MCS based on the relay information and transmits the data to the RS.

Abstract: 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 S1 has no error and S2 has an error, a relay station (1) does not perform relay transmission at time t (Null) and relay-transmits S1* to a base station at time t+T. That is, in this case, the relay station (1) relay-transmits at time t+T only S1 to be transmitted at time t when no error is contained in either S1 or S2. Moreover, when S1 has an error and S2 has no error, the relay station (1) relay-transmits S2 at time t and does not perform relay transmission at time t+T (Null). That is, in this case, the relay station (1) relay-transmits only S2 to be transmitted at time t+T at time t if no error is contained in either S1 or S2.

Abstract: A wireless communication method capable of selecting an optimum relay station, while preventing degradation of the throughput. According to this wireless communication method, in a frame 2, a relay station (1) has a line quality being equal to or greater than Th and hence decides that the delay amount be ?t1, while a relay station (2) has a line quality being less than Th and hence decides that the delay amount be ?t2. The relay station (1) uses ?t1 of the frame 2 to transmit a relayed signal to a base station. On the other hand, recognizing, by a lapse of ?t2, that the relay station (1) used ?t1 to transmit the relayed signal, the relay station (2) stops the transmission of the relayed signal. Accordingly, the base station receives only the relayed signal from the relay station (1) having the better line quality. Thus, when the line quality of the relay station (1) is better than that of the relay station (2), the relayed signal from the relay station (1) can be preferentially transmitted.

Abstract: A mobile station wherein the power consumption can be suppressed. In a frame 3, this mobile station (100) transmits, to both a base station (200) and a relay station (150), a multicarrier signal comprising a plurality of subcarriers that have been controlled in transmission power on the basis of reception quality information 1 (Processes (3) and (3)?: first transmission). In a frame 4, the mobile station (100) transmits, only to the base station (200), a multicarrier signal comprising a plurality of subcarriers that have been controlled in transmission power on the basis of reception quality information 2 (Process (5): second transmission). In this case, the mobile station (100) selects subcarriers in which reception qualities indicated by the reception quality information 2 are lower than a target quality, and the mobile station (100) then transmits, to the base station (200), a multicarrier signal comprising only those subcarriers in which the reception qualities are lower than the target quality.

Abstract: 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 (104) 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 (105) judges whether the decoded result has an error by using CRC (Cyclic Redundancy Check). An encoding unit (106) performs error-correction-encoding of the decoded result and obtains a systematic bit after error-corrected-encoded and a parity bit.

Abstract: A BCA signal reproduction method for reading a BCA signal from a disc includes detecting a peak value of the BCA signal (peak detection value); detecting a bottom value of the BCA signal using a wide tracking bandwidth (first bottom detection value); detecting a bottom value of the BCA signal using a narrow tracking bandwidth (second bottom detection value); detecting a signal indicating whether the current portion is a no-signal portion where the BCA signal is not recorded or a signal portion where the BCA signal is recorded, on the basis of the peak detection value, the first bottom detection value, and the second bottom detection value; determining a slice level for binarizing the BCA signal on the basis of the detected signal and at least the peak detection value, the first bottom detection value, and the second bottom detection value; and binarizing the BCA signal.

Abstract: An optical disk apparatus for recording data on and reproducing data from a recordable optical disk includes a storage unit and a control unit. The storage unit is configured to store specific useful information necessary for at least one of recording data on and reproducing data from the optical disk. The control unit is configured to record the useful information stored in the storage unit in a test write area of the optical disk, and reproduce and use the recorded useful information when the optical disk is placed in the optical disk apparatus.

Abstract: There is provided a recording apparatus which modulates record data by a predetermined modulation method and records record patterns corresponding to the record data on an optical disk, including a random data generator which generates random data as the record data, a data exchange processor which performs exchange processing on the random data so as to equalize a frequency of appearance of each of the record patterns relative to the entire record patterns on the optical disk corresponding to the respective random data, a modulator which modulates the random data subjected to the exchange processing by the predetermined modulation method, an optical head which records record patterns corresponding to the modulated random data on the optical disk, and reproduces the modulated random data from the recorded record patterns, and a record learning unit which calculates correction amounts for recorded positions of the respective record patterns based on the reproduced random data.

Abstract: According to one embodiment, in an information recording and reproducing apparatus, a record data correction unit generates correction data for correcting a record waveform generated according to record data. Further, the information recording and reproducing apparatus generates discrimination data for use in pattern discrimination performed to generate the correction data, using decoded data outputted from a PRML signal processing unit and the record data, and outputs the generated discrimination data to the record data correction unit.

Abstract: 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.

Abstract: An information recording-reproducing apparatus includes a recording-reproducing unit configured to record information given by encoding the data in predetermined data blocks with an error correction code, the data blocks being generated by multiplexing information indicating the positions of the defect management areas, on the information storage medium and to decode the encoded information with the error correction code and reproduce the decoded information and a complementary unit configured to complement the information indicating the positions of the defect management areas on the basis of the data in data units smaller than the data blocks, when an error can be corrected in the data units or when no error is detected even if the error correction in the data blocks cannot be performed for the information that is encoded and recorded.

Abstract: A rewritable information storage medium includes a user area for storing user data, a spare area serving as a replacement area for storing user data that was unable to be stored in the defective area, and a plurality of defect management areas. The same defect management information is stored in the plurality of defect management areas. Even when all errors of the plurality of defect management areas are uncorrectable on a predetermined data unit basis, in the case where the error of the defect management information stored in any one of the defect management areas is correctable on a data unit basis smaller than the predetermined data unit, the defect management information is compensated for on the basis of the smaller data unit.

Abstract: An optical disk device which decodes data recorded on an optical disk, comprises a first measuring unit which measure a cycle of a plurality of first synchronous signal regions VFO contained in a reproduction signal from an optical pickup, a cycle comparing unit which compares the measurement result of the first measuring unit with a first predetermined cycle, a second measuring unit which measures a cycle of a plurality of second synchronous signal regions SYNC which are contained in the reproduction signal from the optical pickup and have the cycle shorter than that of the plurality of first synchronous signal regions VFO, a cycle comparing unit which compares the measurement result of the second measuring unit with a second predetermined cycle, and an oscillator which generates a clock signal CKS for sampling the reproduction signal on the basis of the comparison results of the first and second cycle comparing units.

Abstract: An information reproducing apparatus according to the present invention is capable of reproducing an information storage medium storing BCA information recorded in a first area and RF information recorded in a second area on an outer side of the first area. The information reproducing apparatus includes an optical pickup to radiate laser light onto the first and second areas and detect reflected light thereof; a reproducing system unit to reproduce an RF signal and a BCA signal on the basis of the reflected light; and a focus control unit to control focusing by setting a focus position to a signal layer of the optical disc when the RF signal is to be reproduced and control defocusing by displacing the focus position from the signal layer when the BCA signal is to be reproduced, thereby equivalently suppressing a high-frequency component of the BCA signal.