Patent US6208699B1 successfully refreshed from Google Patents.
US6208699B1
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Method and apparatus for detecting zero rate frames in a communications system
Assignee: Qualcomm Inc
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Filing: 1999-09-01
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Granted: 2001-03-27
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Expires: 2019-09-01
Abstract
Abstract Techniques for detecting zero rate frames in a received data transmission. A modulated signal is received and demodulated in accordance with a particular demodulation format to generate demodulated symbols. The demodulated symbols are partitioned into a number of received frames. For each received frame, a quality metric is computed and compared against a threshold value. The threshold value is selected based, in part, on the quality metrics of received frames. Based on the comparison result, the received frame is indicated as being either transmitted and received in error (i.e., erased or bad) or not transmitted at all (i.e., zero rate or empty). The quality metric can relate to an energy of a received frame, a distance between a received frame and a codeword corresponding to the received frame, or other metrics. The threshold value can be selected based on the quality metrics computed for decoded frames or received frames identified as good, and can be dynamically adjusted based on current information available at the receiver. The method is advantageously used in a CDMA communications system.
Inventors
- 👤 Tao Chen
- 👤 Shimman Patel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:06
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/20; H04L1/208; H03; H03M; H03M13/00; H03M13/37; H03M13/3738; H04B; H04B2201/00; H04B2201/69; H04B2201/707; H04B2201/70703; H04B2201/70705; H04W; H04W52/00; H04W52/04; H04W52/18; H04W52/26
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
107 words
A method for identifying zero rate frames in a received data transmission, the method comprising: receiving a modulated signal; demodulating the modulated signal in accordance with a particular demodulation format to generate demodulated symbols; partitioning the demodulated symbols into a plurality of received frames; computing a quality metric for each of the plurality of received frames; comparing the quality metric for a particular received frame against a threshold value, wherein the threshold value is selected based, in part, on the quality metrics of received frames; and identifying the particular received frame as being a zero rate frame or not a zero rate frame based on the comparing.
Claim 2
Independent Claim
107 words
A method for identifying zero rate frames in a received data transmission, the method comprising: receiving a modulated signal; demodulating the modulated signal in accordance with a particular demodulation format to generate demodulated symbols; partitioning the demodulated symbols into a plurality of received frames; computing a quality metric for each of the plurality of received frames; comparing the quality metric for a particular received frame against a threshold value, wherein the threshold value is selected based, in part, on the quality metrics of received frames; and identifying the particular received frame as being a zero rate frame or not a zero rate frame based on the comparing.
Claim 3
Dependent Claim
18 words
The method of claim 1 , wherein the quality metric relates to an energy of a received frame.
Claim 4
Dependent Claim
26 words
The method of claim 2 , wherein the quality metric for each received frame is computed as a sum of squared symbols for the received frame.
Claim 5
Dependent Claim
26 words
The method of claim 1 , wherein the quality metric relates to a distance between a received frame and a codeword corresponding to the received frame.
Claim 6
Dependent Claim
35 words
The method of claim 4 , further comprising: decoding each received frame into a decoded frame; and re-encoding the decoded frame in accordance with an encoding format to generate the codeword for the decoded frame.
Claim 7
Dependent Claim
24 words
The method of claim 4 , further comprising: decoding each received frame into a decoded frame, and wherein the codeword comprises the decoded frame.
Claim 8
Dependent Claim
24 words
The method of claim 1 , further comprising: decoding each received frame in accordance with a particular decoding hypothesis to generate a decoded frame.
Claim 9
Dependent Claim
31 words
The method of claim 7 , wherein the particular decoding hypothesis includes a particular frame format and a particular rate selected from among a set of possible frame formats and rates.
Claim 10
Dependent Claim
28 words
The method of claim 8 , wherein the set of possible frame formats includes 5 msec and 20·L msec frames, where L is an integer one or greater.
Claim 11
Dependent Claim
19 words
The method of claim 8 , wherein the set of possible rates includes full, half, quarter, and eight rates.
Claim 12
Dependent Claim
26 words
The method of claim 7 , wherein the threshold value is selected based, in part, on the quality metrics of decoded frames identified as good frames.
Claim 13
Dependent Claim
26 words
The method of claim 11 , further comprising: checking CRC bits associated with a decoded frame to identify whether the decoded frame is a good frame.
Claim 14
Dependent Claim
21 words
The method of claim 7 , wherein the particular received frame is decoded and identified as not being a good frame.
Claim 15
Dependent Claim
24 words
The method of claim 1 , wherein the threshold value is selected based, in part, on statistics of the quality metrics of received frames.
Claim 16
Dependent Claim
20 words
The method of claim 14 , wherein the quality metrics of received frames are weighted equally to generate the statistics.
Claim 17
Dependent Claim
20 words
The method of claim 14 , wherein the quality metrics of received frames are weighted unequally to generate the statistics.
Claim 18
Dependent Claim
13 words
The method of claim 1 , wherein the threshold value is dynamically adjustable.
Claim 19
Dependent Claim
24 words
The method of claim 1 , further comprising: denormalizing the demodulated symbols with an energy of a pilot signal transmitted with the data transmission.
Claim 20
Dependent Claim
17 words
The method of claim 1 , wherein the demodulation format is specified by IS-2000 or IS-95-A standard.
Claim 21
Dependent Claim
116 words
A receiver subsystem in a communications system comprising: a demodulator configured to receive and demodulate a modulated signal in accordance with a particular demodulation format to generate demodulated symbols; and a data processor operatively coupled to the demodulator, the data processor configured to partition the demodulated symbols into a plurality of received frames, compute a quality metric for each of the plurality of received frames, compare the quality metric for a particular received frame against a threshold value, wherein the threshold value is selected based, in part, on the quality metrics of received frames, and identify the particular received frame as being a zero rate frame or not a zero rate frame based on the comparison.
Claim 22
Dependent Claim
116 words
A receiver subsystem in a communications system comprising: a demodulator configured to receive and demodulate a modulated signal in accordance with a particular demodulation format to generate demodulated symbols; and a data processor operatively coupled to the demodulator, the data processor configured to partition the demodulated symbols into a plurality of received frames, compute a quality metric for each of the plurality of received frames, compare the quality metric for a particular received frame against a threshold value, wherein the threshold value is selected based, in part, on the quality metrics of received frames, and identify the particular received frame as being a zero rate frame or not a zero rate frame based on the comparison.
Claim 23
Dependent Claim
24 words
The receiver subsystem of claim 20 , wherein the data processor includes: a symbol accumulation circuit configured to receive and accumulate the demodulated symbols.
Claim 24
Dependent Claim
31 words
The receiver subsystem of claim 20 , wherein the data processor includes: a decoder configured to receive and decode the plurality of received frames to generate a plurality of decoded frames.
Claim 25
Dependent Claim
41 words
The receiver subsystem of claim 22 , wherein the data processor further includes: a CRC circuit coupled to the decoder, the CRC circuit configured to receive and check the plurality of decoded frames to identify good frames among the decoded frames.
Claim 26
Dependent Claim
29 words
The receiver subsystem of claim 22 , wherein the data processor further includes: an encoder coupled to the decoder, the encoder configured to receive and re-encode the decoded frames.
Claim 27
Dependent Claim
19 words
The receiver subsystem of claim 20 , wherein the quality metric relates to an energy for a received frame.
Claim 28
Dependent Claim
27 words
The receiver subsystem of claim 25 , wherein the quality metric for a received frame is computed as a sum of squared symbols for the received frame.
Claim 29
Dependent Claim
27 words
The receiver subsystem of claim 20 , wherein the quality metric relates to a distance between the received frame and a codeword corresponding to the received frame.
Claim 30
Dependent Claim
189 words
In a CDMA communications system, a receiver subsystem operable to identify zero rate frames in a received data transmission, the receiver subsystem comprising: a demodulator configured to receive and demodulate a modulated signal in accordance with a particular demodulation format to generate demodulated symbols; a decoder operatively coupled to the demodulator, the decoder configured to receive the demodulated symbols as a plurality of received frames, and to decode the plurality of received frames into a plurality of decoded frames; a CRC circuit coupled to the decoder, the CRC circuit configured to receive and check the plurality of decoded frames to identify good frames among the decoded frames; and a metric calculation unit operatively coupled to the demodulator or the decoder, the metric calculation unit configured to compute a quality metric for each of the plurality of received frames, compare the quality metric for a particular received frame against a threshold value, wherein the threshold value is selected based, in part, on the quality metrics of received frames, and identify the particular received frame as being a zero rate frame or not a zero rate frame based on the comparison.
Claim 31
Dependent Claim
189 words
In a CDMA communications system, a receiver subsystem operable to identify zero rate frames in a received data transmission, the receiver subsystem comprising: a demodulator configured to receive and demodulate a modulated signal in accordance with a particular demodulation format to generate demodulated symbols; a decoder operatively coupled to the demodulator, the decoder configured to receive the demodulated symbols as a plurality of received frames, and to decode the plurality of received frames into a plurality of decoded frames; a CRC circuit coupled to the decoder, the CRC circuit configured to receive and check the plurality of decoded frames to identify good frames among the decoded frames; and a metric calculation unit operatively coupled to the demodulator or the decoder, the metric calculation unit configured to compute a quality metric for each of the plurality of received frames, compare the quality metric for a particular received frame against a threshold value, wherein the threshold value is selected based, in part, on the quality metrics of received frames, and identify the particular received frame as being a zero rate frame or not a zero rate frame based on the comparison.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-26 | 2004-09-25 | 2005-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-26 | 2008-09-25 | 2009-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-26 | 2012-09-25 | 2013-03-27 | $7700.00 | Window Closed / Lapsed |