Data unit retransmission
First Claim
1. A device including:
- modulation circuitry including;
an input; and
modulated output; and
coding circuitry including a data unit output coupled to the input of the modulation circuitry, the coding circuitry configured to;
receive, from demodulation circuitry at a destination node, an indication of an error in a first data unit, the first data unit including;
a first bit; and
a second bit, where a modulation pattern used by the modulation circuitry to represent the second bit is determined responsive to the first bit;
responsive to the indication, determine to retransmit the first data unit;
alter the first data unit to generate a retransmission data unit by changing the first bit to alter the modulation pattern used by the modulation circuitry to represent the second bit; and
send the retransmission data unit to the modulation circuitry for transmission via the modulated output, the modulated output having the altered modulation pattern that differs from the modulation pattern of the previously transmitted first data unit.
4 Assignments
0 Petitions
Accused Products
Abstract
A source node may send a first data unit to a destination node. To send the first data unit, the source node may transmit a modulation pattern over a transmission medium. In some cases, particular data units may correspond to modulation patterns with features that cause errors in transmission. The source node may receive an indication of an error from the destination node. To avoid repeated errors the retransmission, coding circuitry at the source node may alter data within the first data unit to generate a retransmission data unit. The alteration may result in the retransmission data unit corresponding to a modulation pattern different from that of the first data unit. The new modulation pattern may lack the error causing features and reduce the chance of repeated errors.
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Citations
20 Claims
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1. A device including:
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modulation circuitry including; an input; and modulated output; and coding circuitry including a data unit output coupled to the input of the modulation circuitry, the coding circuitry configured to; receive, from demodulation circuitry at a destination node, an indication of an error in a first data unit, the first data unit including; a first bit; and a second bit, where a modulation pattern used by the modulation circuitry to represent the second bit is determined responsive to the first bit; responsive to the indication, determine to retransmit the first data unit; alter the first data unit to generate a retransmission data unit by changing the first bit to alter the modulation pattern used by the modulation circuitry to represent the second bit; and send the retransmission data unit to the modulation circuitry for transmission via the modulated output, the modulated output having the altered modulation pattern that differs from the modulation pattern of the previously transmitted first data unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method including:
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receiving an indication of an error in a first data unit, the first data unit including; a first bit; and a second bit, where a modulation pattern used to represent the second bit is determined responsive to the first bit; responsive to the indication, determining to retransmit the first data unit; and altering the first data unit to generate a retransmission data unit by changing the first bit to alter the modulation pattern used to represent the second bit. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A modem including:
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modulation circuitry configured to; couple to a transmission medium; apply an inverse discrete Fourier transform (iDFT) to a portion of first data transmission unit (DTU) including a first header and a data payload portion to generate a first modulation pattern representing the data payload portion during transmission over the transmission medium; apply the iDFT to a portion of a retransmission DTU including a second header and the data payload portion to generate a second modulation pattern representing the data payload portion during transmission over the transmission medium, the second modulation pattern different from the first; coding circuitry coupled to the modulation circuitry, the coding circuitry configured to; send the portion of the first DTU to the modulation circuitry for transmission over the transmission medium; receive, in response to the portion of the first DTU, a retransmission request; responsive to the retransmission request determining to retransmit the portion of the first DTU; advance a field of the first header to a next value in a pre-determined sequence to generate the second header; generate the portion of the retransmission DTU with the second header such that the modulation circuitry represents the data payload portion using the second modulation pattern instead of the first modulation pattern when the iDFT is applied to the portion of the retransmission DTU; and send the portion of the retransmission DTU to the modulation circuitry for transmission over the transmission medium. - View Dependent Claims (19, 20)
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Specification