Automatic retransmission query (ARQ) with inner code for generating multiple provisional decodings of a data packet
First Claim
1. A method of communicating a data packet from a transmitter to a receiver in a communication system, the method comprising the steps of:
- encoding the data packet in a first convolutional encoder having a first rate to thereby generate an inner code including at least first and second encoded versions of the data packet;
encoding the first and second encoded versions of the data packet in a second convolutional encoder having a second rate to thereby generate first and second transmit packets;
transmitting the first transmit packet to the receiver; and
storing the second transmit packet for use in retransmission.
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Accused Products
Abstract
The invention discloses techniques for providing automatic retransmission query (ARQ) functions in a communication system. A transmitter in the system applies an input data packet to a first convolutional encoder operating at a first rate to generate an inner code including multiple encoded packets. The encoded packets are interleaved and applied to a second convolutional encoder operating at a second rate which generates an outer code including a transmit packet generated from each of the encoded packets. A first transmit packet is sent to a receiver, which decodes the transmit packet in a Viterbi decoder operating at the second rate to generate a decoded version of the first transmit packet. The decoded version is inverted to provide a first provisional decoding of the input packet. If a cyclic redundancy code (CRC) check of the first provisional decoding is passed, the receiver sends an ACK signal to the transmitter and no retransmission is required. If the check is not passed, the transmitter sends one or more additional transmit packets, which are processed in a manner similar to the first transmit packet to generate one or more additional provisional decodings of the input data packet. If a CRC check of a given one of these additional provisional decodings is passed, the receiver accepts it as the input packet and sends an ACK signal to the transmitter. If none pass the CRC check, the receiver may combine decoded versions of the transmit packets, and apply the result to a Viterbi decoder operating at the first rate to generate another provisional decoding of the input packet. This provisional decoding is accepted as the input packet if it passes a CRC check.
112 Citations
39 Claims
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1. A method of communicating a data packet from a transmitter to a receiver in a communication system, the method comprising the steps of:
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encoding the data packet in a first convolutional encoder having a first rate to thereby generate an inner code including at least first and second encoded versions of the data packet; encoding the first and second encoded versions of the data packet in a second convolutional encoder having a second rate to thereby generate first and second transmit packets; transmitting the first transmit packet to the receiver; and storing the second transmit packet for use in retransmission. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of processing transmit packets received from a transmitter in a communication system, the transmit packets corresponding to encoded versions of a given data packet, the method comprising the steps of:
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decoding a first transmit packet in a first decoder having a first rate to thereby generate a first version of the data packet; providing a retransmission indication to the transmitter if the first version of the data packet is not sufficiently accurate; receiving a second transmit packet in response to the retransmission indication; and decoding the second transmit packet in the first decoder to thereby generate a second version of the data packet. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. An apparatus for communicating a data packet to a receiver in a communication system, the apparatus comprising:
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a first convolutional encoder for encoding the data packet at a first rate to generate an inner code including at least first and second encoded versions of the data packet; a second convolutional encoder for encoding the first and second encoded versions of the data packet at a second rate to generate first and second transmit packets; and a processor operative to direct the transmission of the first transmit packet to the receiver, and to direct the storage of the second transmit packet for use in retransmission. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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26. An apparatus for processing transmit packets received from a transmitter in a communication system, the transmit packets corresponding to encoded versions of a given data packet, the apparatus comprising:
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a first decoder for decoding a first transmit packet at a first rate to generate a first version of the data packet; and a processor operative to provide a retransmission indication to the transmitter if the first version of the data packet is not sufficiently accurate, and to receive a second transmit packet in response to the retransmission indication, wherein the first decoder decodes the second transmit packet to generate a second version of the data packet. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. A communication system comprising:
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a first transmitter encoder in a transmitter of said communication system for encoding a data packet at a first rate to generate an inner code including at least first and second encoded versions of the data packet; a second transmitter encoder for encoding the first and second encoded versions of the data packet at a second rate to generate first and second transmit packets; a transmitter processor operative to direct the transmission of the first transmit packet from the transmitter to a receiver of the communication system, and to direct the storage of the second transmit packet for use in retransmission; a first receiver decoder for decoding the first transmit packet at a first rate to generate a first version of the data packet; and a receiver processor operative to provide a retransmission indication to the transmitter if the first version of the data packet is not sufficiently accurate, and to receive a second transmit packet in response to the retransmission indication, wherein the first decoder decodes the second transmit packet to generate a second version of the data packet. - View Dependent Claims (37, 38, 39)
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Specification