US5581575A
Expired / Lapsed
US
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Method and apparatus for transmission of variable rate digital data
Assignee: Qualcomm Inc
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Filing: 1995-10-05
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Granted: 1996-12-03
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Expires: 2015-10-05
Abstract
Abstract A communication system for transmitting variable rate data is disclosed wherein redundancy is added to the variable rate data to provide repetition symbols. The repetition symbol data is transmitted with symbol energy scaled in accordance to the rate of the variable rate data when the variable rate data is greater than or equal to a nominal data rate. When the variable rate data is less than the nominal data rate, the symbol data is transmitted at nominal symbol energy and redundancy is removed by transmission gating of a proportion of the transmission symbol data determined in accordance with the rate of the variable rate data. Furthermore, a receiver for receiving the variable rate data is disclosed which uses the redundancy in the transmitted data symbol stream to make a corrected estimate of the transmitted symbol data.
Inventors
- 👤 Ephraim Zehavi
- 👤 Andrew J. Viterbi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:44
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/08; H04L25/00; H04L25/02; H03; H03M; H03M13/00; H03M13/27; H03M13/2703; H03M13/2707; H04B; H04B1/00; H04B1/69; H04B1/707; H04L1/0001; H04L1/0009; H04L1/0013; H04L1/004; H04L1/0041; H04L1/0043; H04L1/0045; H04L1/0052; H04L1/0056; H04L1/0064; H04L1/0065; H04L1/0071; H04N; H04N1/00; H04N1/46; H04N1/56
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
170 words
An apparatus for transmitting a variable rate data packet of data symbols, said apparatus comprising: repetition generator means for receiving said packet and when the number of said data symbols in said packet is less than a first value generating duplicates of said data symbols and combining said data symbols and said duplicates of said data symbols in said packet; and transmitter means for transmitting said packet from said repetition generator means, wherein when the number of data symbols in said packet equals said first value, transmitting said packet at a first energy level and when the number of data symbols in said packet is less than said first value and greater than a second value, transmitting said packet at a second energy level which is less than said first energy level, and when the number of data symbols in said packet is less than said second value gating ones of said data symbols and said duplicates of said data symbols and transmitting said packet at a third energy level.
Claim 2
Independent Claim
170 words
An apparatus for transmitting a variable rate data packet of data symbols, said apparatus comprising: repetition generator means for receiving said packet and when the number of said data symbols in said packet is less than a first value generating duplicates of said data symbols and combining said data symbols and said duplicates of said data symbols in said packet; and transmitter means for transmitting said packet from said repetition generator means, wherein when the number of data symbols in said packet equals said first value, transmitting said packet at a first energy level and when the number of data symbols in said packet is less than said first value and greater than a second value, transmitting said packet at a second energy level which is less than said first energy level, and when the number of data symbols in said packet is less than said second value gating ones of said data symbols and said duplicates of said data symbols and transmitting said packet at a third energy level.
Claim 3
Dependent Claim
35 words
The apparatus of claim 1 further comprising spreading means interposed between said repetition generator means and said transmitter means for receiving said packet and modulating said packet in accordance with a spread spectrum modulation format.
Claim 4
Dependent Claim
53 words
The apparatus of claim 2 wherein said spreading means comprises: first PN generator means for generating a first pseudorandom noise sequence; and first mixing means for receiving said packet and said first pseudorandom noise sequence and for spreading said packet in accordance with said first pseudorandom noise sequence to output a spread packet.
Claim 5
Dependent Claim
88 words
The apparatus of claim 3 wherein said spreading means further comprises: second PN generator means for generating a second pseudorandom noise sequence; second mixing means for receiving said spread packet and said second pseudorandom noise sequence and for digitally mixing said spread packet with said second pseudorandom noise sequence; third PN generator means for generating a third pseudorandom noise sequence; and third mixing means for receiving said spread packet and said third pseudorandom noise sequence and for digitally mixing said spread packet with said third pseudorandom noise sequence.
Claim 6
Dependent Claim
44 words
The apparatus of claim 4 further comprising offset quadrature phase shift keying (OQPSK) modulation means interposed between said spreading means and said transmitter means for receiving said spread packet and modulating said packet in accordance with an offset quadrature phase shift keying modulation format.
Claim 7
Dependent Claim
45 words
The apparatus of claim 1 wherein said transmitter means is further for reordering said data symbols and said duplicates of said data symbols in accordance with a pseudorandom reordering format when the number of data symbols in said packet is less than said second value.
Claim 8
Dependent Claim
33 words
The apparatus of claim 1 further comprising an encoder means preceding said repetition generator means for receiving said packet and for encoding said data symbols in accordance with an error correction encoding format.
Claim 9
Dependent Claim
43 words
The apparatus of claim 7 further comprising an interleaver means interposed between said encoder means and said repetition generator means for receiving said packet from said encoder means and for reordering said data symbols in said packet in accordance with an interleaving format.
Claim 10
Dependent Claim
39 words
The apparatus of claim 1 wherein said second energy level is one of a set of possible second energy levels and wherein said third energy level is the minimum energy level in said set of possible second energy levels.
Claim 11
Dependent Claim
35 words
The apparatus of claim 1 wherein the ratio between said second energy level and said first energy level equals the ratio between the said number of data symbols in said packet and said first value.
Claim 12
Independent Claim
154 words
A method for transmitting a variable rate data packet of data symbols, said method comprising the steps of: receiving said packet; when the number of said data symbols in said packet is less than a first value generating duplicates of said data symbols and combining said data symbols and said duplicates of said data symbols in said packet; when the number of data symbols in said packet equals said first value, transmitting said packet at a first energy level; when the number of data symbols in said packet is less than said first value and greater than a second value, transmitting said packet at a second energy level which is less than said first energy level; and when the number of data symbols in said packet is less than said second value gating ones of said data symbols and said duplicates of said data symbols and transmitting said packet at a third energy level.
Claim 13
Independent Claim
154 words
A method for transmitting a variable rate data packet of data symbols, said method comprising the steps of: receiving said packet; when the number of said data symbols in said packet is less than a first value generating duplicates of said data symbols and combining said data symbols and said duplicates of said data symbols in said packet; when the number of data symbols in said packet equals said first value, transmitting said packet at a first energy level; when the number of data symbols in said packet is less than said first value and greater than a second value, transmitting said packet at a second energy level which is less than said first energy level; and when the number of data symbols in said packet is less than said second value gating ones of said data symbols and said duplicates of said data symbols and transmitting said packet at a third energy level.
Claim 14
Dependent Claim
21 words
The method of claim 11 further comprising the step of modulating said packet in accordance with a spread spectrum modulation format.
Claim 15
Dependent Claim
47 words
The method of claim 12 wherein said step of modulating said packet in accordance with a spread spectrum modulation format comprises the steps of: generating a first pseudorandom noise sequence; and spreading said packet in accordance with said first pseudorandom noise sequence to output a spread packet.
Claim 16
Dependent Claim
60 words
The method of claim 13 wherein said step of modulating said packet in accordance with a spread spectrum modulation format further comprises the steps of: generating a second pseudorandom noise sequence; digitally mixing said spread packet with said second pseudorandom noise sequence; generating a third pseudorandom noise sequence; and digitally mixing said spread packet with said third pseudorandom noise sequence.
Claim 17
Dependent Claim
25 words
The method of claim 14 further comprising the step of modulating said packet in accordance with an offset quadrature phase shift keying (OQPSK) modulation format.
Claim 18
Dependent Claim
43 words
The method of claim 11 further comprising the step of reordering said data symbols and said duplicates of said data symbols in accordance with a pseudorandom reordering format when the number of data symbols in said packet is less than said second value.
Claim 19
Dependent Claim
22 words
The method of claim 11 further comprising the step of encoding said data symbols in accordance with an error correction encoding format.
Claim 20
Dependent Claim
23 words
The method of claim 17 further comprising the step of reordering said data symbols in said packet in accordance with an interleaving format.
Claim 21
Dependent Claim
39 words
The method of claim 1 wherein said second energy level is one of a set of possible second energy levels and wherein said third energy level is the minimum energy level in said set of possible second energy levels.
Claim 22
Dependent Claim
35 words
The method of claim 11 wherein the ratio between said second energy level and said first energy level equals the ratio between the said number of data symbols in said packet and said first value.
Claim 23
Independent Claim
112 words
A system for transmitting a variable rate data packet of data symbols, said system comprising: a repetition generator having an input and having an output; a transmitter having an input coupled to said repetition generator output and having an output; a spread spectrum modulator interposed between said repetition generator and said transmitter having an input coupled to said repetition generator output and having an output coupled to said transmitter input, said spread spectrum modulator comprising: a first PN generator having an output; and a first mixer having a first input coupled to said repetition generator output and having a second input coupled to said first PN generator output and having an output.
Claim 24
Independent Claim
112 words
A system for transmitting a variable rate data packet of data symbols, said system comprising: a repetition generator having an input and having an output; a transmitter having an input coupled to said repetition generator output and having an output; a spread spectrum modulator interposed between said repetition generator and said transmitter having an input coupled to said repetition generator output and having an output coupled to said transmitter input, said spread spectrum modulator comprising: a first PN generator having an output; and a first mixer having a first input coupled to said repetition generator output and having a second input coupled to said first PN generator output and having an output.
Claim 25
Dependent Claim
75 words
The system of claim 21 wherein said spread spectrum modulator comprises: a second PN generator having an output; a second mixer having a first input coupled to said first mixer output and having a second input coupled to said second PN generator output; a third PN generator having an output; and third mixer having a first input coupled to said first mixer output and having a second input coupled to said third PN generator output.
Claim 26
Dependent Claim
44 words
The system of claim 21 further comprising an offset quadrature phase shift keying modulator having a first input coupled to said second mixer output and having a second input coupled to said third mixer output and having an output coupled to said transmitter input.
Claim 27
Independent Claim
155 words
A system for transmitting a variable rate data packet of data symbols, said system comprising: a repetition generator having an input connected to receive said packet of data symbols for generating duplicates of said data symbols when the number of data symbols in said packet is less than a first value and having an output at which a combination of said data symbols and said duplicates of said data symbols in said packet is provided as a data packet; and a transmitter having an input connected to receive the output of said repetition generator and having an output from which data symbols received from said repetition generator are transmitted at a first energy level when the number of data symbols in said packet equals said first value, at a second energy level, which is less than said first energy level, when the number of data symbols in said packet is less than said first value.
Claim 28
Independent Claim
155 words
A system for transmitting a variable rate data packet of data symbols, said system comprising: a repetition generator having an input connected to receive said packet of data symbols for generating duplicates of said data symbols when the number of data symbols in said packet is less than a first value and having an output at which a combination of said data symbols and said duplicates of said data symbols in said packet is provided as a data packet; and a transmitter having an input connected to receive the output of said repetition generator and having an output from which data symbols received from said repetition generator are transmitted at a first energy level when the number of data symbols in said packet equals said first value, at a second energy level, which is less than said first energy level, when the number of data symbols in said packet is less than said first value.
Claim 29
Dependent Claim
58 words
The system of claim 24 wherein said transmitter transmits data symbols: at said second energy level when the number of data symbols in said packet is less than said first value but greater than a second value, and at a third energy level when the number of data symbols in said packet is less than said second value.
Claim 30
Dependent Claim
37 words
The system of claim 24 further comprising a spread spectrum modulator interposed between said repetition generator and said transmitter having an input coupled to said repetition generator output and having an output coupled to said transmitter input.
Claim 31
Dependent Claim
48 words
The system of claim 26 wherein said spread spectrum modulator comprises: a first PN generator having an output; and a first mixer having a first input coupled to said repetition generator output and having a second input coupled to said first PN generator output and having an output.
Claim 32
Dependent Claim
76 words
The system of claim 27 wherein said spread spectrum modulator comprises: a second PN generator having an output; a second mixer having a first input coupled to said first mixer output and having a second input coupled to said second PN generator output; a third PN generator having an output; and a third mixer having a first input coupled to said first mixer out-put and having a second input coupled to said third PN generator output.
Claim 33
Dependent Claim
44 words
The system of claim 27 further comprising an offset quadrature phase shift keying modulator having a first input coupled to said second mixer output and having a second input coupled to said third mixer output and having an output coupled to said transmitter input.
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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) | 1999-12-03 | 2000-06-03 | 2000-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-03 | 2004-06-03 | 2004-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-03 | 2008-06-03 | 2008-12-03 | $7700.00 | Window Closed / Lapsed |