Systems and methods for detecting discontinuous transmission (DTX) using cyclic redundancy check results to modify preliminary DTX classification

• US 20030152169A1
• Filed: 02/13/2002
• Published: 08/14/2003
• Est. Priority Date: 02/13/2002
• Status: Active Grant

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Chen, Dayong
• Granted Patent: US 7,061,999 B2
• Time in Patent Office: Days
• US Class Current: 375/340
• CPC Class Codes: H04L 1/0047 Decoding adapted to other signal detection operation in conjunction with sequence estimation or equalization H04L25/03286
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 1/201 Frame classification, e.g. bad, good or erased frame indication per se H04L1/0082

Abstract

A received information signal is decoded to obtain the received information and to produce at least one feature of the received information signal. The received information signal is preliminarily classified as containing a normal burst or a truncated burst based upon the at least one feature, to obtain a preliminary classification. Cyclic redundancy checking of the received information that is decoded is performed. The received information signal is then further classified as containing a normal burst or a truncated burst based upon the preliminary classification and whether the cyclic redundancy checking is valid, to obtain a further classification. The received information signal may be still further classified as containing a normal burst or a truncated burst based upon the further classification and at least one transition rule for normal bursts and truncated bursts between the received information signal and a previously received information signal.

Claims

1. A method of detecting whether a normal burst or a truncated burst is present in a received information signal, the method comprising:

decoding the received information signal to obtain the received information and to produce at least one feature of the received information signal;

preliminarily classifying the received information signal as containing a normal burst or a truncated burst based upon the at least one feature, to obtain a preliminary classification;

cyclic redundancy checking the received information that is decoded; and

further classifying the received information signal as containing a normal burst or a truncated burst based upon the preliminary classification and whether the cyclic redundancy checking is valid, to obtain a further classification.

2. A method according to claim 1 wherein the further classifying is followed by:

still further classifying the received information signal as containing a normal burst or a truncated burst based upon the further classification and at least one transition rule for normal bursts and truncated bursts between the received information signal and a previously received information signal.

3. A method according to claim 1:

wherein the cyclic redundancy checking comprises cyclic redundancy checking the received information that is decoded and previously received information that is decoded; and

wherein the further classifying comprises further classifying the received information signal as containing a normal burst or a truncated burst based upon the preliminary classification and whether the cyclic redundancy checking of the received information that is decoded and the previously received information that is decoded are valid, to obtain a further classification.

4. A method according to claim 3 wherein the further classifying is followed by:

still further classifying the received information signal as containing a normal burst or a truncated burst based upon the further classification and at least one transition rule for normal bursts and truncated bursts between the received information signal and the previously received information signal.

5. A method according to claim 1 wherein the at least one feature comprises an estimated bit error rate, a Viterbi decoder metric and/or a distance measurement between a demodulated sub-sequence and a corresponding reference sequence.

6. A method according to claim 1:

wherein the preliminarily classifying comprises preliminarily classifying the received information signal as containing truncated burst based upon the at least one feature, to obtain a preliminary classification as a truncated burst; and

wherein the further classifying comprises further classifying the received information signal as containing a normal burst based upon the preliminary classification as a truncated burst upon the cyclic redundancy checking being valid, to obtain a further classification as a normal burst.

7. A method according to claim 3:

wherein the preliminarily classifying comprises preliminarily classifying the received information signal as containing truncated burst based upon the at least one feature, to obtain a preliminary classification as a truncated burst; and

wherein the further classifying comprises further classifying the received information signal as containing a normal burst based upon the preliminary classification as a truncated burst, the cyclic redundancy checking of the received information that is decoded not being valid and the cyclic redundancy checking of the previously received information that is decoded being valid, to obtain a further classification as a normal burst.

8. A method according to claim 2 wherein the at least one transition rule for normal bursts and truncated bursts between the received information signal and a previously received information signal comprises a rule that a truncated burst can be included in the received information signal only after comfort noise parameters are included in the previously received information signal.

9. A method of detecting whether a normal burst or a truncated burst is present in a received information signal, the method comprising:

decoding the received information signal to obtain the received information and to produce at least one feature of the received information signal;

cyclic redundancy checking the received information that is decoded; and

classifying the received information signal as containing a normal burst or a truncated burst based upon the at least one feature of the received information signal and the cyclic redundancy checking.

10. A method according to claim 9 wherein the classifying comprises:

classifying the received information signal as containing a normal burst or a truncated burst based upon the at least one feature of the received information signal, the cyclic redundancy checking and at least one transition rule for normal bursts and truncated bursts between the received information signal and a previously received information signal.

11. A system for detecting whether a normal burst or a truncated burst is present in a received information signal, the system comprising:

a decoder that is configured to decode the received information signal to obtain the received information and to produce at least one feature of the received information signal;

a preliminary classifier that is configured to preliminarily classify the received information signal as containing a normal burst or a truncated burst based upon the at least one feature, to obtain a preliminary classification;

a cyclic redundancy checker that is configured to cyclic redundancy check the received information that is decoded; and

a second stage classifier that is configured to further classify the received information signal as containing a normal burst or a truncated burst based upon the preliminary classification and whether the cyclic redundancy checking is valid, to obtain a further classification.

12. A system according to claim 11 further comprising:

a third stage classifier that is configured to still further classify the received information signal as containing a normal burst or a truncated burst based upon the further classification and at least one transition rule for normal bursts and truncated bursts between the received information signal and a previously received information signal.

13. A system according to claim 11:

wherein the cyclic redundancy checker is further configured to cyclic redundancy check the received information that is decoded and previously received information that is decoded; and

wherein the second stage classifier is further configured to classify the received information signal as containing a normal burst or a truncated burst based upon the preliminary classification and whether the cyclic redundancy checking of the received information that is decoded and the previously received information that is decoded are valid, to obtain a further classification.

14. A system according to claim 13 further comprising:

a third stage classifier that is configured to still further classify the received information signal as containing a normal burst or a truncated burst based upon the further classification and at least one transition rule for normal bursts and truncated bursts between the received information signal and the previously received information signal.

15. A system according to claim 11 wherein the at least one feature comprises an estimated bit error rate, a Viterbi decoder metric and/or a distance measurement between a demodulated sub-sequence and a corresponding reference sequence.

16. A system according to claim 11:

wherein the preliminarily classifier is further configured to preliminarily classify the received information signal as containing truncated burst based upon the at least one feature, to obtain a preliminary classification as a truncated burst; and

wherein the second stage classifier is further configured to classify the received information signal as containing a normal burst based upon the preliminary classification as a truncated burst upon the cyclic redundancy checking being valid, to obtain a further classification as a normal burst.

17. A system according to claim 13:

wherein the preliminarily classifier is further configured to preliminarily classify the received information signal as containing truncated burst based upon the at least one feature, to obtain a preliminary classification as a truncated burst; and

wherein the second stage classifier is further configured to classify the received information signal as containing a normal burst based upon the preliminary classification as a truncated burst, the cyclic redundancy checking of the received information that is decoded not being valid and the cyclic redundancy checking of the previously received information that is decoded being valid, to obtain a further classification as a normal burst.

18. A system according to claim 12 wherein the at least one transition rule for normal bursts and truncated bursts between the received information signal and a previously received information signal comprises a rule that a truncated burst can be included in the received information signal only after comfort noise parameters are included in the previously received information signal.

19. A system for detecting whether a normal burst or a truncated burst is present in a received information signal, the system comprising:

a decoder that is configured to decode the received information signal to obtain the received information and to produce at least one feature of the received information signal;

a cyclic redundancy checker that is configured to cyclic redundancy check the received information that is decoded; and

a classifier that is configured to classify the received information signal as containing a normal burst or a truncated burst based upon the at least one feature of the received information signal and the cyclic redundancy checking.

20. A system according to claim 19 wherein the classifier is further configured to classify the received information signal as containing a normal burst or a truncated burst based upon the at least one feature of the received information signal, the cyclic redundancy checking and at least one transition rule for normal bursts and truncated bursts between the received information signal and a previously received information signal.

21. A wireless component comprising:

a wireless receiver that is configured to receive an information signal containing a normal burst or a truncated burst;

a decoder that is configured to decode the received information signal to obtain the received information and to produce at least one feature of the received information signal;

a preliminary classifier that is configured to preliminarily classify the received information signal as containing a normal burst or a truncated burst based upon the at least one feature, to obtain a preliminary classification;

a cyclic redundancy checker that is configured to cyclic redundancy check the received information that is decoded; and

a second stage classifier that is configured to further classify the received information signal as containing a normal burst or a truncated burst based upon the preliminary classification and whether the cyclic redundancy checking is valid, to obtain a further classification.

22. A wireless component according to claim 21 further comprising:

a third stage classifier that is configured to still further classify the received information signal as containing a normal burst or a truncated burst based upon the further classification and at least one transition rule for normal bursts and truncated bursts between the received information signal and a previously received information signal.

23. A wireless component according to claim 21:

wherein the cyclic redundancy checker is further configured to cyclic redundancy check the received information that is decoded and previously received information that is decoded; and

wherein the second stage classifier is further configured to classify the received information signal as containing a normal burst or a truncated burst based upon the preliminary classification and whether the cyclic redundancy checking of the received information that is decoded and the previously received information that is decoded are valid, to obtain a further classification.

24. A wireless component according to claim 23 further comprising:

a third stage classifier that is configured to still further classify the received information signal as containing a normal burst or a truncated burst based upon the further classification and at least one transition rule for normal bursts and truncated bursts between the received information signal and the previously received information signal.

25. A wireless component according to claim 21 wherein the at least one feature comprises an estimated bit error rate, a Viterbi decoder metric and/or a distance measurement between a demodulated sub-sequence and a corresponding reference sequence.

26. A wireless component according to claim 21:

wherein the preliminarily classifier is further configured to preliminarily classify the received information signal as containing truncated burst based upon the at least one feature, to obtain a preliminary classification as a truncated burst; and

wherein the second stage classifier is further configured to classify the received information signal as containing a normal burst based upon the preliminary classification as a truncated burst upon the cyclic redundancy checking being valid, to obtain a further classification as a normal burst.

27. A wireless component according to claim 23:

wherein the preliminarily classifier is further configured to preliminarily classify the received information signal as containing truncated burst based upon the at least one feature, to obtain a preliminary classification as a truncated burst; and

wherein the second stage classifier is further configured to classify the received information signal as containing a normal burst based upon the preliminary classification as a truncated burst, the cyclic redundancy checking of the received information that is decoded not being valid and the cyclic redundancy checking of the previously received information that is decoded being valid, to obtain a further classification as a normal burst.

28. A wireless component according to claim 22 wherein the at least one transition rule for normal bursts and truncated bursts between the received information signal and a previously received information signal comprises a rule that a truncated burst can be included in the received information signal only after comfort noise parameters are included in the previously received information signal.

29. A wireless component comprising:

a wireless receiver that is configured to receive an information signal containing a normal burst or a truncated burst;

a decoder that is configured to decode the received information signal to obtain the received information and to produce at least one feature of the received information signal;

a cyclic redundancy checker that is configured to cyclic redundancy check the received information that is decoded; and

a classifier that is configured to classify the received information signal as containing a normal burst or a truncated burst based upon the at least one feature of the received information signal and the cyclic redundancy checking.

30. A wireless component according to claim 29 wherein the classifier is further configured to classify the received information signal as containing a normal burst or a truncated burst based upon the at least one feature of the received information signal, the cyclic redundancy checking and at least one transition rule for normal bursts and truncated bursts between the received information signal and a previously received information signal.