Retransmission Control Method And Communications Device
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Abstract
A retransmission control method comprising: generating N parity check matrices; generating a generator matrix containing a check symbol generator matrix contained in the first parity check matrix; transmitting the codeword generated by using the generator matrix to another communications device; generating, when the communications device receives a NAK in response to the codeword, a first additional parity by using the second parity check matrix; and retransmitting the first additional parity to the another communications device.
36 Citations
17 Claims
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1-8. -8. (canceled)
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9. A retransmission control method for a communications device that transmits a codeword to another communications device using low-density parity check codes as error correcting codes, the retransmission control method comprising:
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generating N parity check matrices optimized at N code rates, respectively, where N is a positive integer, wherein a k-th code rate is lower than a (k−
1)-th code rate, where k is a positive integer from 2 to N;
converting a first parity check matrix so that the first parity check matrix contains a check symbol generator matrix;
generating a generator matrix containing the check symbol generator matrix;
transmitting the codeword generated by using the generator matrix to the another communications device;
generating, when the communications device receives a negative acknowledgment from the another communications device in response to the codeword, a first additional parity by using a second parity check matrix;
retransmitting the first additional parity to the another communications device;
generating, when the communications device receives a negative acknowledgment from the another communications device in response to a (k−
1)-th additional parity generated by using a k-th parity check matrix, a k-th additional parity by using the (k+1)-th parity check matrix; and
retransmitting the k-th additional parity to the another communications device. - View Dependent Claims (10, 11, 12, 13)
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14. A communications device that transmits a codeword to another communications device using low-density parity check codes as error correcting codes, the communications device comprising:
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a retransmission control unit that controls a retransmission when the communications device receives a negative acknowledgement from the another communications device;
an encoding unit that includes a parity-check-matrix generating unit that generates N parity check matrices optimized at N code rates, respectively, where N is a positive integer, wherein a k-th code rate is lower than a (k−
1)-th code rate, where k is a positive integer from 2 to N;
a converting unit that converts a first parity check matrix so that the first parity check matrix contains a check symbol generator matrix;
a generator-matrix generating unit that generates a generator matrix containing the check symbol generator matrix; and
a codeword generating unit that generates the codeword by using the generator matrix; and
a modulation unit that applies predetermined digital modulation to the codeword and transmits the codeword to the another communications device, wherein when the communications device receives a negative acknowledgement from the another communications device in response to the codeword, the encoding unit generates a first additional parity by using a second parity check matrix and the modulation unit applies predetermined digital modulation to the first additional parity, and when the communications device receives a negative acknowledgement from the another communications device in response to a (k−
1)-th additional parity generated by using a k-th parity check matrix, the encoding unit generates a k-th additional parity by using the (k+1)-th parity check matrix and the modulation unit applies predetermined digital modulation to the k-th additional parity. - View Dependent Claims (15, 16)
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17. A communications device that uses Low-Density Parity-Check codes as error correcting codes, transmits a codeword that has been encoded at a predetermined code rate of initial transmission, and transmits an additional parity in retransmission.
Specification