Burst detector

• US 20030063576A1
• Filed: 07/16/2002
• Published: 04/03/2003
• Est. Priority Date: 09/28/2001
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: DiFazio, Robert A.
• Granted Patent: US 7,180,881 B2
• Time in Patent Office: Days
• US Class Current: 370/280
• CPC Class Codes: H04B 1/7093 Matched filter type
• CPC Class Codes: H04B 1/71 the interference being narrowband interference
• CPC Class Codes: H04B 1/7105 Joint detection techniques, e.g. linear detectors
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04L 1/0039 other detection of signalling, e.g. detection of TFCI explicit signalling H04L1/0046, H04L27/0012 and H04L25/0262 take precedence

Abstract

The present invention is a receiver for receiving a communication signal divided into a plurality of timeslots, wherein the timeslots include a plurality of channels, including a burst detector for detecting when a selected one of the plurality of channels of the communication is received. The burst detector comprises a noise estimation device for determining a scaled noise power estimate of the selected one of the timeslots, a matched filter for detecting signal power of the selected one of the timeslots and a signal power estimation device, responsive for the matched filter, for generating a signal power estimate of the, selected one of the timeslots. A comparator responsive to the scaled noise power estimate the signal power estimate is also included in the burst detector for generating a burst detection signal when the signal power estimate is greater than the scaled noise power estimate, and a data estimation device, responsive to the burst detection signal, for decoding the plurality of channels.

Claims

1. A receiver for receiving communication signals in time frames divided into a plurality of timeslots, wherein said timeslots may include data signals for a plurality of channels, including a burst detector for detecting when a selected timeslot is received without selected ones of the plurality of channels, the burst detector comprising:

a noise estimation device for determining a scaled noise power estimate of a signal received in said selected timeslot;

a matched filter for detecting a predetermined code within a signal received in said timeslot;

a signal power estimation device, responsive for said matched filter, for generating a signal power estimate of a detected code;

a comparator, responsive to said noise power estimation and said signal power estimation devices, for generating a burst detection signal when a signal power estimate is greater than a noise power estimate; and

a data estimation device for decoding the received signal of said timeslot when a burst detection signal is generated.

2. The receiver of claim 1 wherein said data estimation device comprises:

a code detection device for generating signal codes in response to a burst detection signal;

a decoder for decoding a received signal in response to signal codes received from said code detection device; and

a transport format combination index (TFCI) decoder, coupled to said decoder, for detecting a TFCI signal in a decoded received signal;

said TFCI signal being representative of the number of selected channels in said selected timeslot.

3. The receiver of claim 2 further comprising a demultiplexer responsive to said data estimation device, for verifying that said selected timeslot includes channel data for each selected channel and generating a monitoring signal when channel data is present.

4. The receiver of claim 3 wherein said burst detector ceases detection of a received signal when a monitoring signal is generated and said TFCI signal indicates that one or more of said selected channels have been received in the timeslot.

5. The receiver of claim 4 wherein said burst detector continues to detect said received signal when said TFCI signal indicates that no selected channels have been received in said timeslot.

6. The receiver of claim 1 wherein said plurality of channels are allocated to one or more coded composite transport channels (CCTrChs) within said selected timeslot;

a selected CCTrCh being associated with said receiver.

7. The receiver of claim 6 wherein said data estimation device comprises:

a code detection device for generating signal codes in response to a burst detection signal;

a decoder for decoding a received signal in response to signal codes received from said code detection device; and

a transport format combination index (TFCI) decoder, coupled to said decoder, for detecting a TFCI signal in a decoded received signal;

said TFCI signal being representative of the number of selected channels allocated to a selected CCTrCh.

8. The receiver of claim 7 further comprising a demultiplexer responsive to said data estimation device, for verifying that said selected CCTrCh includes channel data and generating a monitoring signal when channel data is present.

9. The receiver of claim 3 wherein said burst detector ceases detection of a received signal when a monitoring signal is generated and said TFCI signal indicates that one or more of said selected channels have been received in the CCTrCh.

10. The receiver of claim 4 wherein said burst detector continues to detect said received signal when said TFCI signal indicates that no selected channels have been received in said CCTrCh.

11. The receiver of claim 7 further including a plurality of burst detectors, each associated with at least one of a plurality of selected CCTrChs, for detecting when a selected timeslot is received without selected channels associated with the burst detectors respective CCTrCh.

12. The receiver of claim 1 wherein said burst detector further comprises a preliminary transport format combination index (TFCI) decoder responsive to said matched filter for determining TFCI power estimates for each of a plurality of TFCI words in a received signal;

said noise estimation device using each of said TFCI power estimates to determine said scaled noise power estimate; and

said signal power estimation device using a largest of said TFCI power estimates to generate said signal power estimate.

13. The receiver of claim 1 wherein said signal power estimation decoder is a transport format combination index decoder which determines TFCI power estimates for each of a plurality of TFCI words in the received signal;

and

said power estimate being the largest of said TFCI power estimates.

14. The receiver of claim 1 wherein said signal power estimation device comprises:

a transport format combination index decoder (TFCI) for determining a TFCI power estimate of a selected TFCI word in the received signal;

a decision feed back loop for determining a symbol power estimate of said received signal, comprising;

a demodulator for generating symbol decisions;

a conjugator coupled to said demodulator, for conjugating said symbol decisions; and

a symbol power estimator, responsive to said conjugated symbol decisions and said matched filter outputs, for generating a symbol power estimate; and

said signal power estimate being the combination of said TFCI power estimate and said symbol power estimate.

15. The receiver of claim 1 wherein said signal power estimate device comprises

a decision feed back loop for determining a symbol power estimate of said received signal, comprising:

a demodulator for generating symbol decisions;

a conjugator coupled to said demodulator, for conjugating said symbol decisions; and

a symbol power estimator, responsive to said conjugated symbol decisions and said matched filter outputs, for generating a symbol power estimate; and

said signal power estimate being the symbol power estimate.

16. The receiver of claim 1 wherein said noise estimator is a matched filter for detecting a nearly orthogonal code within said received signal, said magnitude of said detected orthogonal code being the noise power estimate;

said signal power estimation device being a transport format combination index decoder for determining a TFCI power estimate of a selected TFCI word in the received signal; and

said TFCI power estimate being said signal power estimate.

17. A method for monitoring communication signals in time frames divided into a plurality of timeslots, wherein said timeslots may include data signals for a plurality of channels, and detecting when a selected timeslot is received without selected ones of the plurality of channels, the method comprising the steps of:

determining a scaled noise power estimate of any signal received in said selected timeslot;

detecting a predetermined code within the signal received in said timeslot;

generating a signal power estimate of the detected code;

generating a burst detection signal when said signal power estimate is greater than the noise power estimate; and

decoding the received signal of said timeslot when a burst detection signal is generated.

18. The method of claim 17 further comprising the steps of:

generating signal codes in responses to said burst detection signal, said decoding of the received signal responsive to said signal codes;

detecting a transport format combination index (TFCI) signal in said decoded received signal representing the number of selected channels in said selected timeslot;

verifying that said selected timeslot includes channel data; and

generating a monitoring signal when channel data is present in said selected timeslot.

19. The method of claim 18 wherein said monitoring of said received signal ceases in response to said monitoring signal and TFCI indicates that one or more of said selected channels have been received in the timeslot.

20. The method of claim 19 wherein said monitoring of said received signal continues when said TFCI signal indicates that no selected channels have been received in said timeslot.

21. The method of claim 17 wherein said plurality of channels are allocated to one or more selected coded composite transport channels (CCTrCh) within said selected timeslot.

22. The method of claim 21 further comprising the steps of:

generating signal codes in responses to said burst detection signal, said decoding of the received signal response to said signal codes;

detecting a transport format combination index (TFCI) signal in said decoded received signal representing the number of selected channels in said selected CCTrCh;

verifying that said selected CCTrCh includes channel data; and

generating a monitoring signal when channel data is present in said selected CCTrCh.

23. The method of claim 22 wherein said monitoring of said received signal ceases in response to said monitoring signal and TFCI indicates that one or more of said selected channels have been received in the CCTrCh.

24. The method of claim 23 wherein said monitoring of said received signal continues when said TFCI signal indicates that no selected channels have been received in said selected CCTrCh.

25. The method of claim 17 wherein said generation of said signal power estimate comprises the steps of determining a largest TFCI power estimate out of a plurality of TFCI power estimates for a plurality of TFCI words in said received signal, said largest TFCI power estimate being said signal power estimate;

said determination of the scaled noise power uses the plurality of TFCI power estimates, said largest TFCI power estimate being excluded, to generate said noise power estimate.

26. The method of claim 17 wherein said generation of said signal power estimate comprises the steps of determining a largest TFCI power estimate out of a plurality of TFCI power estimates for a plurality of TFCI words in said received signal, said largest TFCI power estimate being said signal power estimate.

27. The method of claim 17 wherein said generation of said signal power estimate comprises the steps of:

determining a transport format combination index (TFCI) power estimate of a selected TFCI word in the received signal;

determining-a symbol power estimate of said received signal; and

combining said TFCI power estimate with said symbol power estimate to generate said signal power estimate.

28. The method of claim 17 wherein said generation of said signal power estimate comprises the steps of:

generating symbol decisions;

conjugating said symbol decisions; and

combining said conjugated symbol decisions and said predetermined code to generate said signal power estimate.

29. The method of claim 17 wherein said determination of said scaled noise power comprises the step of detecting a nearly orthogonal code within said received signal, said nearly orthogonal code magnitude being the noise estimate;

said generation of said signal power estimate comprises the steps of determining a largest TFCI power estimate out of a plurality of TFCI power estimates for a plurality of TFCI words in said received signal, said largest TFCI power estimate being said signal power estimate.