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 Title: |
US6111912:
Method and apparatus for detecting the sub-rate of a punctured data packet for a multi-rate transmission scheme
[ Derwent Title ]
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| Country: |
US United States of America
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| Inventor: |
Cohen, Edith; Chatham, NJ
Lou, Hui-Ling; Murray Hill, NJ
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| Assignee: |
Lucent Technologies Inc., Murray Hill, NJ
other patents from LUCENT TECHNOLOGIES INC. (722326) (approx. 6,959)
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| Published / Filed: |
2000-08-29
/ 1996-06-21
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| Application Number: |
US1996000667754
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| IPC Code: |
Advanced:
H04L 1/00;
H04L 1/08;
Core:
more...
IPC-7:
H04B 17/00;
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| ECLA Code: |
H04L1/00B7C; H04L1/00B5B; H04L1/00B7R1; H04L1/00B7V; H04L1/08;
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| U.S. Class: |
Current:
375/225;
375/340;
Original:
375/225;
375/340;
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| Field of Search: |
375/224,225,377,340,341,342,365,366,368
370/165,252,281,253,468,335,342,320,324
340/825,825.06
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| Priority Number: |
| 1996-06-21 |
US1996000667754 |
| 1995-11-09 |
US1995000555737 |
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| Abstract: |
A method for detecting the transmission sub-rate of a data packet whose symbols are punctured prior to transmission as with an IS-95 transmission with a 13 kbps speech encoder. Sub-rates are detected by first regrouping the received symbols so as to exclude those symbols for which one or more of its repetitions were punctured. The regrouped symbols are then examined for consecutive identical soft decision symbols, i.e., the repetitive pattern used by the transmitter to mask the sub-rate, with statistical methods used to account for the effects of noise and power bit insertion. The repetitive pattern is then matched to the appropriate sub-rate.
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| Primary / Asst. Examiners: |
Luther, William;
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| INPADOC Legal Status: |
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Family Legal Status Report
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| Parent Case: |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation in part of U.S. patent application Ser. No. 08/555,737, filed on Nov. 9, 1995 and entitled "Method for Detecting The Sub-Rate of A Data Packet For a Multi-Rate Transmission Scheme" now abandoned. This application and the earlier filed application are commonly assigned.
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| Family: |
Show 3 known family members
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First Claim:
Show all 4 claims |
What is claimed is:
1. A method for detecting a data sub-rate of a transmitted data packet comprising a plurality of symbols, said plurality of symbols comprising symbols of a data block wherein said data sub-rate is one of four possible sub-rates, a first sub-rate corresponding to a first pattern, where the data packet comprises symbols of said data block, a second sub-rate corresponding to a second pattern wherein the data packet comprises symbols of said data block with each said data block symbol repeated consecutively one additional time resulting in arrangements of pairs of consecutive identical symbols in the data packet, a third sub-rate corresponding to a third pattern wherein the data packet comprises symbols of said data block with each said data block symbol repeated consecutively three additional times resulting in arrangements of quartets of consecutive identical symbols in the data packet, a fourth sub-rate corresponding to a fourth pattern wherein the data packet comprises symbols of said data block with each said data block symbol repeated consecutively seven additional times resulting in arrangements of octets of consecutive identical symbols in the data packet, and wherein the data packet is punctured prior to a transmission so as to remove every third and fifth symbol from every set of six symbols, said method comprising the steps of:
- regrouping said plurality of symbols of said transmitted data packet so as to exclude punctured symbols;
- determining a particular pattern of said regrouped symbols of said transmitted data packet by computing variables based on said first, second, third and fourth patterns and comparing said variables to respective threshold values, each threshold value correlated to one of said four possible sub-rates;
- identifying, after said computing and comparing steps, the sub-rate which corresponds to said particular pattern of said regrouped symbols of said transmitted data packet, wherein said computing step comprises the steps of:
- computing 3 sum variables S1, S2, and S3, one sum variable for each sub-rate other than said first sub-rate;
- computing 3 lower-limit variables LS1, LS2, and LS3, one lower-limit variable for each sub-rate other than said first sub-rate;
- computing 3 upper-limit variables US1, US2, and US3, one upper-limit variable for each sub-rate other than said first sub-rate;
- computing 3 discriminator variable [Figure] and [Figure] one discriminator variable for each sub-rate other than said first sub-rate; and
- recognizing a particular pattern, of said first, second, third, or fourth patterns, present in said data packet from said 3 discriminator variables.
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| Background / Summary: |
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| Drawing Descriptions: |
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| Description: |
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| Forward References: |
Show 11 U.S. patent(s) that reference this one
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| Foreign References: |
None
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| Other Abstract Info: |
DERABS G2000-564785
DERABS G2000-564785
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| Other References: |
"Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular Standard," TIA/EIA Interim Standard 95 (Jul. 1993).
E. Cohen and H. Lou, "Multi-Rate Detection for the IS-95 CDMA forward traffic channels," IEEE Globecom '95 (Nov. 1995).
Personal Station/Base Station Compatibility Requirements for 1.8-2.0 GHz CDMA personal communication system, ANSI J-STD-008, (Mar. 1995).
H. Lou, "Implementing the Viterbi Algorithm," IEEE Signal Processing Magazine, vol. 12, No. 5, pp. 42-52 (Sep. 1995).
(11 pages)
Cited by 11 patents
[ISI abstract]
G.D. Forney Jr., "The Viterbi Algorithm," IEEE Proceedings, vol. IT-61, No. 3, pp. 268-278 (Mar. 1973).
(11 pages)
Cited by 160 patents
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