IPC분류정보
국가/구분 |
United States(US) Patent
등록
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국제특허분류(IPC7판) |
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출원번호 |
US-0098470
(2002-03-18)
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발명자
/ 주소 |
- Hessel,Clifford
- Voglewede,Paul E.
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출원인 / 주소 |
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대리인 / 주소 |
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인용정보 |
피인용 횟수 :
3 인용 특허 :
8 |
초록
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A system and method for demodulating a data packet in an automatic repeat request communication system is disclosed. Specifically, in a communication system that combines the energy of an initially transmitted data packet with the energy of a retransmitted version of the data packet, the inventive s
A system and method for demodulating a data packet in an automatic repeat request communication system is disclosed. Specifically, in a communication system that combines the energy of an initially transmitted data packet with the energy of a retransmitted version of the data packet, the inventive system and method measures the "usability" of the initially transmitted data packet that fails an error-checking procedure and the "usability" of a retransmitted version of the data packet. If the initially transmitted version and the retransmitted version of the data packet are both "usable", the energies of the data packets are combined. The combined data packet is then subjected to the error-checking procedure. If the combined data packet fails the error-checking procedure, the energy of either the combined packet or the retransmitted packet is stored for later combination with a subsequently-retransmitted version of the data packet.
대표청구항
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What is claimed is: 1. A method of receiving a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver comprising the steps of: (a) receiving, demodulating, and error checking said signal; (b) performing a usabil
What is claimed is: 1. A method of receiving a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver comprising the steps of: (a) receiving, demodulating, and error checking said signal; (b) performing a usability check on said encoded data packet in said signal in response to an error condition in the error-checking step; (c) storing the signal as received containing said encoded data packet in response to a positive usability condition; (d) receiving a retransmission of the signal containing the encoded data packet; (e) combining the stored signal as received containing the encoded data packet with the retransmitted signal containing the encoded data packet; and (f) demodulating the combined signal to thereby obtain the data packet. 2. The method of claim 1 wherein the step of combining signals containing the encoded data packets comprises coherently adding the signals containing the data packets. 3. The method of claim 1 wherein the ARQ-enabled communication system is a traceback system. 4. The method of claim 1 wherein the ARQ-enabled communication system is a stop-and-wait system. 5. The method of claim 1 wherein step (a) includes the following step: (i) in response to a no error condition in the error-checking step of said encoded data packet, sending an acknowledgement signal from the receiver to the transmitter. 6. The method of claim 5 replacing step (f) with the following steps: (f) demodulating the combined signals containing the encoded data packet; and (g) repeating steps (b) through (f) using the combined data packet as the signal as received containing the encoded data packet until an acknowledgment signal is sent from the receiver to the transmitter to thereby receive said data packet at the receiver. 7. The method of claim 1 wherein steps (b) and (c) are replaced with the following steps: (b) in response to an error condition in the error-checking step of said encoded data packet, performing the following steps: (i) sending a negative acknowledgment signal from the receiver to the transmitter; and (ii) performing a usability check on said encoded data packet; (1) in response to a positive usability condition in the usability-checking step of said encoded data packet, storing the signal as received containing said encoded data packet at the receiver to thereby create a first stored data packet if no first stored data packet exists, otherwise storing said combined data packet from step (e) as said first stored data packet; and (2) in response to a non-positive usability condition in the usability-checking step of said encoded data packet, discarding said signal as received containing the encoded data packet. 8. The method of claim 7 wherein step (e) comprises the following steps: (i) copying said retransmitted signal containing the encoded data packet and storing said copy of said retransmitted signal containing the encoded data packet to thereby create a second stored data packet; and (ii) combining said second stored data packet with said first stored data packet to thereby create a combined data packet if said first stored data packet exists, otherwise using said second stored data packet as said combined data packet. 9. The method of claim 1 wherein steps (b) and (c) are replaced with the following steps: (b) in response to an error condition in the error-checking step of said encoded data packet, performing the following steps: (i) sending a negative acknowledgment signal from the receiver to the transmitter; and (ii) performing a usability check on said encoded data packet; (1) in response to a positive usability condition in the usability-checking step of said encoded data packet, storing the signal as received containing said encoded data packet at the receiver to thereby create a first stored data packet; and (2) in response to a non-positive usability condition in the usability-checking step of said encoded data packet, discarding said signal as received containing the encoded data packet. 10. The method of claim 9 wherein step (e) comprises the following steps: (i) receiving at the receiver a retransmission of said encoded data packet contained in said signal in step (a) in response to receipt at the transmitter of said negative acknowledgement signal; and (ii) combining said retransmitted signal containing the encoded data packet with said first stored data packet to thereby create a combined data packet if said first stored data packet exists, otherwise using said retransmitted signal containing the encoded data packet as said combined data packet. 11. A receiver for receiving a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver comprising: (a) a demodulator and error checking means for demodulating and error checking a signal as received containing an encoded data packet; (b) usability checking means for performing a usability check on said encoded data packet in response to an error condition output from said error-checking means; (c) memory for storing the signal as received containing said encoded data packet in response to a positive usability condition; and (d) combining means for combining the stored signal as received containing the data packet with a received retransmitted signal containing said encoded data packet, whereby the demodulator demodulates the combined data packet to thereby receive the data packet. 12. The receiver of claim 11 wherein the combining means comprises means for coherently adding the signals containing the encoded data packets. 13. The receiver of claim 11 wherein the ARQ-enabled communication system is a traceback system. 14. The receiver of claim 11 wherein the ARQ-enabled communication system is a stop-and-wait system. 15. A method of communicating a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver comprising the steps of: (a) receiving said signal containing an encoded data packet at the receiver; (b) demodulating said signal as received; (c) performing an error check on said encoded data packet; (i) in response to a no error condition in the error-checking step of said encoded data packet, sending an acknowledgement signal from the receiver to the transmitter; (ii) in response to an error condition in the error-checking step of said encoded data packet, performing the following steps: (1) sending a negative acknowledgment signal from the receiver to the transmitter; (2) performing a usability check on said encoded data packet; (A) in response to a positive usability condition in the usability-checking step of said encoded data packet, storing signal as received containing the encoded data packet at the receiver to thereby create a first stored data packet if no first stored data packet exists, otherwise storing said second stored data packet from step (c)(ii)(4) as said first stored data packet; (B) in response to a non-positive usability condition in the usability-checking step of said encoded data packet, discarding said encoded data packet; (3) receiving at the receiver a retransmission of the signal containing said encoded data packet of step (a) in response to receipt at the transmitter of said negative acknowledgement signal; (4) copying said retransmitted signal containing the encoded data packet and storing said copy of said retransmitted signal containing the encoded data packet to thereby create a second stored data packet; (5) combining said retransmitted signal containing the encoded data packet with said first stored data packet to thereby create a combined data packet if said first stored data packet exists, otherwise using said retransmitted signal containing the encoded data packet as said combined data packet; (6) demodulating said combined data packet; (d) repeating step (c) using the combined data packet as the encoded data packet until an acknowledgment signal is sent from the receiver to the transmitter to thereby communicate said data packet from the transmitter to the receiver. 16. A method of communicating a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver comprising the steps of: (a) receiving said signal containing an encoded data packet at the receiver; (b) demodulating said signal as received; (c) performing an error check on said encoded data packet; (i) in response to a no error condition in the error-checking step of said encoded data packet, sending an acknowledgement signal from the receiver to the transmitter; (ii) in response to an error condition in the error-checking step of said encoded data packet, performing the following steps: (1) sending a negative acknowledgment signal from the receiver to the transmitter; (2) performing a usability check on said encoded data packet; (A) in response to a positive usability condition in the usability-checking step of said encoded data packet, storing said signal as received containing the encoded data packet at the receiver to thereby create a first stored data packet; (B) in response to a non-positive usability condition in the usability-checking step of said encoded data packet, discarding said encoded data packet; (3) receiving at the receiver a retransmission of said encoded data packet contained in said signal in step (a) in response to receipt at the transmitter of said negative acknowledgement signal; (4) combining said retransmitted encoded data packet with said first stored data packet to thereby create a combined data packet if said first stored data packet exists, otherwise using said retransmitted data packet as said combined data packet; (5) demodulating said combined data packet; (d) repeating step (c) using the combined data packet as the encoded data packet until an acknowledgment signal is sent from the receiver to the transmitter to thereby communicate said data packet from the transmitter to the receiver. 17. A method of communicating a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver comprising the steps of: (a) receiving, demodulating, and error checking said signal; (b) performing a usability check on said encoded data packet in said signal in response to an error condition in the error-checking portion of step (a); (c) storing the signal as received containing said encoded data packet in response to a positive usability condition; (d) receiving and error checking a retransmission of the signal containing the encoded data packet; (e) combining the stored signal as received containing the data packet with the retransmitted signal containing the data packet in response to an error condition in the error checking portion of step (d) creating a combined data packet, otherwise transmit an acknowledgement from the receiver to the transmitter; (f) error checking the combined data packet; (g) performing a usability check on said combined data packet in response to an error condition in step (f), otherwise transmit an acknowledgement from the receiver to the transmitter; and (h) repeating steps (d) through (g) until an acknowledgement is sent thereby transmitting said encoded data packet from the transmitter to the receiver. 18. The method of claim 17 wherein the step of combining data packets comprises coherently adding the signals containing the encoded data packets. 19. The method of claim 17 wherein the ARQ-enabled communication system is a traceback system. 20. The method of claim 17 wherein the ARQ-enabled communication system is a stop-and-wait system. 21. A communication system for transmitting a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver comprising: (a) a receiver for receiving, demodulating, and error checking said signal; (b) usability checking means for performing a usability check on said encoded data packet in said signal in response to an error condition in the error-checking portion of step (a); (c) memory for storing said signal as received containing the encoded data packet in response to a positive usability condition; (d) said receiver for receiving and error checking a retransmission of the encoded data packet; (e) combining means for combining the stored data packet with the retransmitted data packet in response to an error condition in the error check of the retransmission of the encoded data packet; (f) transmitter means at the receiver for transmitting an acknowledgement from the receiver to the transmitter in response to a no-error condition in the error check of the retransmission of the encoded data packet; (g) said error checking means for error checking the combined data packet; (h) said usability checking means for performing a usability check on said combined data packet in response to an error condition in step (g); (i) said transmitter means for transmitting an acknowledgement from the receiver to the transmitter in response to a no-error condition in the error check of the retransmission of the encoded data packet; and (j) means for repeating steps (d) through (g) until an acknowledgement is sent thereby transmitting said encoded data packet from the transmitter to the receiver. 22. The system of claim 21 wherein the combining means comprises means for coherently adding the encoded data packets. 23. The system of claim 21 wherein the ARQ-enabled communication system is a traceback system. 24. The system of claim 21 wherein the ARQ-enabled communication system is a stop-and-wait system. 25. A method of communicating a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver comprising the steps of: (a) receiving said signal containing an encoded data packet at the receiver; (b) demodulating said signal as received; (c) performing an error check on said encoded data packet; (i) in response to a no error condition in the error-checking step of said encoded data packet, sending an acknowledgement signal from the receiver to the transmitter; (ii) in response to an error condition in the error-checking step of said encoded data packet, performing the following steps: (1) sending a negative acknowledgment signal from the receiver to the transmitter; (2) performing a usability check on said encoded data packet; (A) in response to a positive usability condition in the usability-checking step of said encoded data packet, storing the signal as received containing said encoded data packet at the receiver to thereby create a first stored data packet; (B) in response to a non-positive usability condition in the usability-checking step of said encoded data packet, discarding said signal as received containing said encoded data packet; (3) receiving at the receiver a retransmission of the signal containing said encoded data packet of step (a) in response to receipt at the transmitter of said negative acknowledgement signal; (4) copying said retransmitted signal containing the encoded data packet and storing said copy of said retransmitted signal containing the encoded data packet to thereby create a second stored data packet; (5) performing an error check on the encoded data packet containing the retransmitted signal; (A) in response to a no error condition in the error-checking step of said encoded data packet, sending an acknowledgement signal from the receiver to the transmitter; (B) in response to an error condition in the error-checking step of said encoded data packet, performing the following steps: (I) determining if said first stored data packet exists; (II) sending a negative acknowledgement from the receiver to the transmitter if no first stored data packet exists; (III) performing the following steps if said first stored data packet exists: (aa) combining said retransmitted signal containing the encoded data packet with said first stored data packet to thereby create a combined data packet; (bb) performing an error check on said combined data packet; (AA) in response to a no error condition in the error-checking step of said combined data packet, sending an acknowledgement signal from the receiver to the transmitter; (BB) in response to an error condition in the error-checking step of said combined data packet, sending a negative acknowledgement signal from the receiver to the transmitter; (IV) performing a usability check on said combined data packet: (aa) in response to a positive usability condition in the usability-checking step of said combined data packet, storing said second stored data packet as said first stored data packet; (bb) in response to a non-positive usability condition in the usability-checking step of said combined data packet, discarding said combined data packet; (6) repeating steps (3) through (5) until an acknowledgement signal is sent from the receiver to the transmitter to thereby communication said data packet from the transmitter to the receiver. 26. A method of communicating a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver comprising the steps of: (a) receiving said signal containing an encoded data packet at the receiver; (b) demodulating said signal as received; (c) performing an error check on said encoded data packet; (i) in response to a no error condition in the error-checking step of said encoded data packet, sending an acknowledgement signal from the receiver to the transmitter; (ii) in response to an error condition in the error-checking step of said encoded data packet, performing the following steps: (1) sending a negative acknowledgment signal from the receiver to the transmitter; (2) performing a usability check on said encoded data packet; (A) in response to a positive usability condition in the usability-checking step of said encoded data packet, storing the signal as received containing said encoded data packet at the receiver to thereby create a first stored data packet; (B) in response to a non-positive usability condition in the usability-checking step of said encoded data packet, discarding said signal as received containing the encoded data packet; (3) receiving at the receiver a retransmission of the signal containing said encoded data packet of step (a) in response to receipt at the transmitter of said negative acknowledgement signal; (4) performing an error check on the encoded data packet contained in the retransmitted signal; (A) in response to a no error condition in the error-checking step of said encoded data packet, sending an acknowledgement signal from the receiver to the transmitter; (B) in response to an error condition in the error-checking step of said encoded data packet, performing the following steps: (I) determining if said first stored data packet exists; (II) sending a negative acknowledgement from the receiver to the transmitter if no first stored data packet exists; (III) performing the following steps if said first stored data packet exists: (aa) combining said retransmitted signal containing the encoded data packet with said first stored data packet to thereby create a combined data packet; (bb) performing an error check on said combined data packet; (AA) in response to a no error condition in the error-checking step of said combined data packet, sending an acknowledgement signal from the receiver to the transmitter; (BB) in response to an error condition in the error-checking step of said combined data packet, sending a negative acknowledgement signal from the receiver to the transmitter; (IV) performing a usability check on said combined data packet: (aa) in response to a positive usability condition in the usability-checking step of said combined data packet, storing said combined data packet as said first stored data packet; (bb) in response to a non-positive usability condition in the usability-checking step of said combined data packet, discarding said combined data packet; (5) repeating steps (3) through (5) until an acknowledgement signal is sent from the receiver to the transmitter to thereby communication said data packet from the transmitter to the receiver. 27. In a method for communicating a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver, the improvement wherein a usability check is performed on the received encoded data packet to determine whether the energy of the received encoded data packet is to be used to demodulate the received packet; wherein the usability check comprises a comparison of minimum and maximum path metrics of a short viterbi decoder or truncated viterbi algorithm. 28. The method of claim 27 wherein the ARQ-enabled communication system is a traceback system. 29. The method of claim 27 wherein the ARQ-enabled communication system is a stop-and-wait system. 30. A method of receiving a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver comprising the steps of: (a) receiving, demodulating, and error checking said signal; (b) comparing the minimum and maximum path metrics of a short viterbi decoder of said encoded data packet in said signal in response to an error condition in the error-checking step; (c) storing the signal as received containing said encoded data packet in response to a favorable comparision; (d) receiving a retransmission of the signal containing the encoded data packet; (e) combining the stored signal as received containing the encoded data packet with the retransmitted signal containing the encoded data packet; and (f) demodulating the combined signal to thereby obtain the data packet. 31. A method of communicating a signal containing an encoded data packet in an ARQ-enabled communication system transmitting packetized data from a transmitter to a receiver comprising the steps of: (a) receiving, demodulating, and error checking said signal; (b) comparing the minimum and maximum path metrics of a short viterbi decoder of said encoded data packet in said signal in response to an error condition in the error-checking step (a); (c) storing the signal as received containing said encoded data packet in response to a positive comparision condition; (d) receiving and error checking a retransmission of the signal containing the encoded data packet; (e) combining the stored signal as received containing the data packet with the retransmitted signal containing the data packet in response to an error condition in the error checking portion of step (d) creating a combined data packet, otherwise transmit an acknowledgement from the receiver to the transmitter; (f) error checking the combined data packet; (g) comparing the minimum and maximum path metrics of a short viterbi decoder of said combined data packet in response to an error condition in step (f), otherwise transmit an acknowledgement from the receiver to the transmitter; and (h) repeating steps (d) through (g) until an acknowledgement is sent thereby transmitting said encoded data packet from the transmitter to the receiver.
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