Retransmission method and transmitter

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.

1 . A retransmission method based on an automatic repeat request (ARQ) in a multiple-input multiple-output (MIMO) communication system using orthogonal frequency division multiplexing (OFDM), the method being performed by a transmitter having a plurality of antennas and comprising:
 attaching a cyclic redundancy check (CRC) for a data signal to generate a CRC attached data signal;   transmitting the CRC attached data signal;   receiving feedback information of acknowledgment (ACK) or negative acknowledgement (HACK) to the CRC attached data signal; and   selecting a retransmission mode for the data signal based on the feedback information,   wherein selecting the retransmission mode includes selecting the retransmission mode for the data signal from a plurality of modes that include a mode of retransmitting using, from the plurality of antennas, an antenna used in previous transmission for the data signal, and simultaneously transmitting a new data signal using, from the plurality of antennas, another antenna which is not the antenna used in the previous transmission for the data signal.   
     
     
         2 . The retransmission method according to  claim 1 , wherein the plurality of modes further include a mode of retransmitting using, from the plurality of antennas, the another antenna which is not the antenna used in previous transmission for the data signal, and simultaneously transmitting the new data signal using, from the plurality of antennas, the antenna used in previous transmission for the data signal. 
     
     
         3 . A retransmission method based on an automatic repeat request (ARQ) in a multiple-input multiple-output (MIMO) communication system using orthogonal frequency division multiplexing (OFDM), the method being performed by a transmitter having a plurality of antennas and comprising:
 attaching a cyclic redundancy check (CRC) for data signals to generate CRC attached data signals;   transmitting the CRC attached data signals;   receiving feedback information of acknowledgment (ACK) or negative acknowledgement (NACK) to the CRC attached data signals; and   selecting a retransmission mode for the data signals based on the feedback information,   wherein selecting the retransmission mode includes selecting the retransmission mode for the data signals from a plurality of modes that include a mode of retransmitting using, from the plurality of antennas, antennas used in previous transmission for the data signals, and simultaneously transmitting new data signals using, from the plurality of antennas, other antennas which is not the antennas used in the previous transmission for the data signals.   
     
     
         4 . The retransmission method according to  claim 3 , wherein the plurality of modes further include a mode of retransmitting using, from the plurality of antennas, the other antennas which is not the antennas used in previous transmission for the data signals, and simultaneously transmitting the new data signals using, from the plurality of antennas, the antennas used in previous transmission for the data signals. 
     
     
         5 . A transmitter having a plurality of antennas in a multiple-input multiple-output (MIMO) communication system using orthogonal frequency division multiplexing (OFDM), the transmitter comprising:
 a cyclic redundancy check (CRC) attaching section that attaches a CRC for a data signal to generate a CRC attached data signal;   a transmitting section that transmits the CRC attached data signal;   a receiving section that receives feedback information of acknowledgment (ACK) or negative acknowledgement (NACK) to the CRC attached data signal; and   a retransmission mode selecting section that selects a retransmission mode for the data signal based on the feedback information,   wherein the retransmission mode selecting section selects the retransmission mode for the data signal from a plurality of modes that include a mode of retransmitting using, from the plurality of antennas, an antenna used in previous transmission for the data signal, and simultaneously transmitting a new data signal using, from the plurality of antennas, another antenna which is not the antenna used in the previous transmission for the data signal.   
     
     
         6 . The transmitter according to  claim 5 , wherein the plurality of modes further include a mode of retransmitting using, from the plurality of antennas, the another antenna which is not the antenna used in previous transmission for the data signal, and simultaneously transmitting the new data signal using, from the plurality of antennas, the antenna used in previous transmission for the data signal. 
     
     
         7 . A transmitter having a plurality of antennas in a multiple-input multiple-output (MIMO) communication system using orthogonal frequency division multiplexing (OFDM), the transmitter comprising:
 a cyclic redundancy check (CRC) attaching section that attaches a CRC for data signals to generate CRC attached data signals;   a transmitting section that transmits the CRC attached data signals;   a receiving section that receives feedback information of acknowledgment (ACK) or negative acknowledgement (NACK) to the CRC attached data signals; and   a retransmission mode selecting section that selects a retransmission mode for the data signals based on the feedback information,   wherein the retransmission mode selecting section selects the retransmission mode for the data signals from a plurality of modes that include a mode of retransmitting using, from the plurality of antennas, antennas used in previous transmission for the data signals, and simultaneously transmitting new data signals using, from the plurality of antennas, other antennas which is not the antennas used in the previous transmission for the data signals.   
     
     
         8 . The transmitter according to  claim 7 , wherein the plurality of modes further include a mode of retransmitting using, from the plurality of antennas, the other antennas which is not the antennas used in previous transmission for the data signals, and simultaneously transmitting the new data signals using, from the plurality of antennas, the antennas used in previous transmission for the data signals.