LPWAN COMMUNICATION PROTOCOL DESIGN WITH TURBO CODES

• US 20200136654A1
• Filed: 10/23/2019
• Published: 04/30/2020
• Est. Priority Date: 10/24/2018
• Status: Active Grant

• Current Assignee: Star Ally International Limited
• Original Assignee: Skaotlom, LLC
• Inventors: Tu, Wenwen, Wensheng
• Granted Patent: US 11,695,431 B2
• Time in Patent Office: Days
• CPC Class Codes: H03M 13/09 Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
• CPC Class Codes: H03M 13/098 using single parity bit
• CPC Class Codes: H03M 13/258 with turbo codes, e.g. Turbo Trellis Coded Modulation [TTCM]
• CPC Class Codes: H03M 13/2963 Turbo-block codes, i.e. turbo codes based on block codes, e.g. turbo decoding of product codes
• CPC Class Codes: H03M 13/2975 Judging correct decoding, e.g. iteration stopping criteria
• CPC Class Codes: H03M 13/617 Polynomial operations, e.g. operations related to generator polynomials or parity-check polynomials
• CPC Class Codes: H03M 13/6306 Error control coding in combination with Automatic Repeat reQuest [ARQ] and diversity transmission, e.g. coding schemes for the multiple transmission of the same information or the transmission of incremental redundancy H03M13/3761, H03M13/3769 and H03M13/635 take precedence
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0061 Error detection codes

Abstract

A method and a decoder for receiving a message encoded in Turbo Codes and modulated for transmission as an analog signal includes: (a) demodulating the analog signal to recover the Turbo Codes; and (b) decoding the Turbo Codes to recover the message using an iterative Turbo Code decoder, wherein the decoding includes performing an error detection after a predetermined number of iterations of the Turbo Code decoder to determine whether or not an error has occurred during the transmission. The predetermined number of iterations may be, for example, two. Depending on the result of the error detection, the decoding may stop, a request for retransmission of the message may be sent, or further iterations of decoding in the Turbo Code decoder may be carried out.

Claims

1. A method for receiving a message encoded in Turbo Codes and modulated for transmission as an analog signal, comprising:

demodulating the analog signal to recover the Turbo Codes; and

decoding the Turbo Codes to recover the message using an iterative Turbo Code decoder, wherein the decoding performs an error detection after a predetermined number of iterations of the Turbo Code decoder to determine whether or not an error has occurred during the transmission.

2. The method of claim 1, wherein the predetermined number of iterations is one.

3. The method of claim 1, wherein decoding stops when the error detection determines that an error has not occurred during the transmission.

4. The method of claim 1, wherein a request for retransmission of the message is sent when the error detection determines that an error has occurred during the transmission.

5. The method of claim 4, wherein a further iteration of decoding is carried out in the Turbo Code decoder when the error detection determines that an error has occurred during the transmission.

6. The method of claim 1, wherein the error detection step comprises evaluating an indicator having a value that is related to a probability that an error has occurred during the transmission.

7. The method of claim 6, wherein the analog signal is transmitted at one of a plurality of analog values, and wherein the probability is based on the received analog signal'"'"'s deviation from the transmitted analog signal.

8. The method of claim 7, wherein the probability relates to P(Y_i-X_i|X_i), where X_i and Y_i represent an analog value of the transmitted analog signal and a value of the received analog value, respectively.

9. The method of claim 8, wherein evaluating the indicator is includes computing:

10. The method of claim 8, wherein the recovered message is used in a Turbo Code encoder to regenerate a regenerated Turbo Code word, and wherein the probability is computed based on the regenerated Turbo Codes.

11. The method of claim 6, wherein the message comprises an error detection code, and wherein the error detection comprises recovering the error detection code.

12. The method of claim 1, wherein the message includes an error detection code, and wherein the error detection comprises decoding the error detection code.

13. The method of claim 12, wherein the error detection comprises determining that a decoding of the error detection code is successful.

14. The method of claim 12, wherein the error detection code is based on cyclic redundancy check.

15. The method of claim 14, wherein the cyclic redundancy check is based on a generator polynomial given by:

g(x)=x¹⁰+x⁹+x⁵+x⁴+x+1

16. A decoder for receiving a message encoded in Turbo Codes and modulated for transmission as an analog signal, comprising:

a demodulator that demodulates the analog signal to recover the Turbo Codes; and

an iterative Turbo Code decoder that decodes the Turbo Codes to recover the message, wherein the decoding includes performing an error detection after a predetermined number of iterations of the Turbo Code decoder to determine whether or not an error has occurred during the transmission.

17. The decoder of claim 16, wherein the predetermined number of iterations is one.

18. The decoder of claim 16, wherein decoding stops when the error detection determines that an error has not occurred during the transmission.

19. The decoder of claim 16, wherein a request for retransmission of the message is sent when the error detection determines that an error has occurred during the transmission.

20. The decoder of claim 19, wherein a further iteration of decoding is carried out in the Turbo Code decoder when the error detection determines that an error has occurred during the transmission.

21. The decoder of claim 16, wherein the error detection comprises evaluating an indicator having a value that is related to a probability that an error has occurred during the transmission.

22. The decoder of claim 21, wherein the analog signal is transmitted at one of a plurality of analog values, and wherein the probability is based on the received analog signal'"'"'s deviation from the transmitted analog signal.

23. The decoder of claim 22, wherein the probability relates to P(Y_i-X_i|X_i), where X_i and Y_i represent an analog value of the transmitted analog signal and a value of the received analog value, respectively.

24. The decoder of claim 23, wherein evaluating the indicator is includes computing:

25. The decoder of claim 23, wherein the recovered message is used in a Turbo Code encoder to regenerate a regenerated Turbo Code word, and wherein the probability is computed based on the regenerated Turbo Codes.

26. The decoder of claim 21, wherein the message comprises an error detection code, and wherein the error detection comprises recovering the error detection code.

27. The decoder of claim 16, wherein the message includes an error detection code, and wherein the error detection comprises decoding the error detection code.

28. The decoder of claim 27, wherein the error detection comprises determining that a decoding of the error detection code is successful.

29. The decoder of claim 27, wherein the error detection code is based on cyclic redundancy check.

30. The decoder of claim 29, wherein the cyclic redundancy check is based on a generator polynomial given by:

g(x)=x¹⁰+x⁹+x⁵+x⁴+x+1