Abstract: In a multi-antenna communication system using LDPC codes, a simple method is used to effectively improve the received quality by performing a retransmittal of less data without restricting applicable LDPC codes. In a case of a non-retransmittal, a multi-antenna transmitting apparatus transmits, from two antennas, LDPC encoded data formed by LDPC encoding blocks. In a case of a retransmittal, the multi-antenna transmitting apparatus uses a transmission method, in which the diversity gain is higher than in the previous transmission, to transmit only a part of the LDPC encoded data as previously transmitted. For example, the only the part of the LDPC encoded data to be re-transmitted is transmitted from the single antenna.

Abstract: In a multi-antenna communication system using LDPC codes, a simple method is used to effectively improve the received quality by performing a retransmittal of less data without restricting applicable LDPC codes. In a case of a non-retransmittal, a multi-antenna transmitting apparatus transmits, from two antennas, LDPC encoded data formed by LDPC encoding blocks. In a case of a retransmittal, the multi-antenna transmitting apparatus uses a transmission method, in which the diversity gain is higher than in the previous transmission, to transmit only a part of the LDPC encoded data as previously transmitted. For example, the only the part of the LDPC encoded data to be re-transmitted is transmitted from the single antenna.

Abstract: An automatic retransmission request control system in an OFDM-MIMO communication system includes a retransmission mode selection part which selects a retransmission mode from among (a) a mode in which to transmit the data which are to be retransmitted, via the same antenna as in the previous transmission, while transmitting, at the same time, new data by use of an antenna via which no data retransmission is requested; (b) a mode in which to transmit the data, which are to be retransmitted, via an antenna via which no retransmission is requested, while transmitting new data via another antenna at the same time; (c) a mode in which to use STBC to retransmit the data via an antenna via which no retransmission is requested; and (d) a mode in which to use STBC to retransmit the data via all the available antennas.

Abstract: An automatic retransmission request control system in an OFDM-MIMO communication system includes a retransmission mode selection part which selects a retransmission mode from among (a) a mode in which to transmit the data, which are to be retransmitted, via the same antenna as in the previous transmission, while transmitting, at the same time, new data by use of an antenna via which no data retransmission is requested; (b) a mode in which to transmit the data, which are to be retransmitted, via an antenna via which no retransmission is requested, while transmitting new data via another antenna at the same time; (c) a mode in which to use STBC to retransmit the data via an antenna via which no retransmission is requested; and (d) a mode in which to use STBC to retransmit the data via all the available antennas.

Abstract: An automatic retransmission request control system in an OFDM-MIMO communication system includes a retransmission mode selection part which selects a retransmission mode from among (a) a mode in which to transmit the data, which are to be retransmitted, via the same antenna as in the previous transmission, while transmitting, at the same time, new data by use of an antenna via which no data retransmission is requested; (b) a mode in which to transmit the data, which are to be retransmitted, via an antenna via which no retransmission is requested, while transmitting new data via another antenna at the same time; (c) a mode in which to use STBC to retransmit the data via an antenna via which no retransmission is requested; and (d) a mode in which to use STBC to retransmit the data via all the available antennas.

Abstract: In a multi-antenna communication system using LDPC codes, a simple method is used to effectively improve the received quality by performing a retransmittal of less data without restricting applicable LDPC codes. In a case of a non-retransmittal, a multi-antenna transmitting apparatus (100) transmits, from two antennas (114A, 114B) , LDPC encoded data formed by LDPC encoding blocks (102A, 102B). In a case of a retransmittal, the multi-antenna transmitting apparatus (100) uses a transmission method, in which the diversity gain is higher than in the previous transmission, to transmit only a part of the LDPC encoded data as previously transmitted. For example, the only the part of the LDPC encoded data to be re-transmitted is transmitted from the single antenna (114A).

Abstract: A system for link adaptation in a MIMO-OFDM system. In this system, the V-BLAST processor (308) performs V-BLAST processing and separates receive signals for the multiple antennas of the transmitter into data streams. The vector information output section (312) sends feedback vector information obtained from V-BLAST processing to the transmitter. The adaptive bit assignment section (304) adaptively controls the number of bits to be assigned to each of the sub-carriers on different antennas, based on the feedback vector information. The adaptive power allocation section (306) adaptively allocates power to each antenna, based on the feedback vector information.

Abstract: In a multi-antenna communication system using LDPC codes, a simple method is used to effectively improve the received quality by performing a retransmittal of less data without restricting applicable LDPC codes. In a case of a non-retransmittal, a multi-antenna transmitting apparatus (100) transmits, from two antennas (114A, 114B) , LDPC encoded data formed by LDPC encoding blocks (102A, 102B). In a case of a retransmittal, the multi-antenna transmitting apparatus (100) uses a transmission method, in which the diversity gain is higher than in the previous transmission, to transmit only a part of the LDPC encoded data as previously transmitted. For example, the only the part of the LDPC encoded data to be re-transmitted is transmitted from the single antenna (114A).

Abstract: An automatic retransmission request control system in OFDM-MIMO communication system. In this system, an ACK/NACK output part (320) of a receiver transmits, to a transmitter, a feedback information of positive or negative response based on the result of a cyclic redundancy check.