US5077753A
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Radio communication system using spread spectrum techniques
Assignee: Proxim Wireless Corp
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Filing: 1990-04-09
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Granted: 1991-12-31
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Expires: 2010-04-09
Abstract
Abstract A spread spectrum radio communication system includes a generator for generating a pseudo-random chipping sequence, a frequency spreader for combining digital data with the pseudo-random chipping sequence to produce a spread spectrum signal, a modulator for modulating the spread spectrum signal for broadcasting over a predefined frequency band, a demodulator for demodulating broadcast spread spectrum signals, a de-spreader that employs single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence, and an extractor for extracting clock and data signals from the output of the de-spreader. The chipping sequence is normally selected from a set of codes including an eleven-bit Barker code, its inverse and reversals of the inverse and non-inverse code.
Inventors
- 👤 Juan Grau, Jr.
- 👤 Brian S. Messenger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:51
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/69; H04B1/707
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
53 words
A transmitter system for use with a spread spectrum radio communication system, comprising: generator means for generating a pseudo-random chipping sequence; frequency spreader means for combining digital data with the pseudo-random chipping sequence to produce a spread spectrum signal; and, modulator means for modulating the spread spectrum signal over a predefined frequency band.
Claim 2
Dependent Claim
53 words
A transmitter system for use with a spread spectrum radio communication system, comprising: generator means for generating a pseudo-random chipping sequence; frequency spreader means for combining digital data with the pseudo-random chipping sequence to produce a spread spectrum signal; and, modulator means for modulating the spread spectrum signal over a predefined frequency band.
Claim 3
Dependent Claim
16 words
A system according to claim 1 wherein the pseudo-random chipping sequence is an eleven-bit Barker code.
Claim 4
Dependent Claim
32 words
A system according to claim 2 wherein the modulator means is of the frequency shift keying type and is driven by the spread spectrum signals to produce a radio-frequency output for broadcasting.
Claim 5
Dependent Claim
43 words
A system according to claim 2 wherein the frequency spreader means includes an exclusive-OR gate means for receiving the scrambled data from the scrambler means and the pseudo-random code signals from the generator means, and for providing the input to the modulator means.
Claim 6
Dependent Claim
27 words
A system according to claim 1 further including scrambler means for scrambling the digital data prior to the data being operated upon by the frequency spreader means.
Claim 7
Dependent Claim
16 words
A system according to claim 5 wherein the pseudo-random chipping sequence is an eleven-bit Barker code.
Claim 8
Dependent Claim
87 words
A transmitter system for use with a spread spectrum radio communication system, comprising: generator means for generating a pseudo-random chipping sequence; frequency spreader means for combining digital data with the pseudo-random chipping sequence to produce a spread spectrum signal; and, modulator means for modulating the spread spectrum signal over a predefined frequency band wherein the pseudo-random chipping sequence is one of a set of codes including non-inverse eleven-bit Barker code, an inverse of the Barker code and a reversed sequence of the inverse or non-inverse Barker code.
Claim 9
Dependent Claim
87 words
A transmitter system for use with a spread spectrum radio communication system, comprising: generator means for generating a pseudo-random chipping sequence; frequency spreader means for combining digital data with the pseudo-random chipping sequence to produce a spread spectrum signal; and, modulator means for modulating the spread spectrum signal over a predefined frequency band wherein the pseudo-random chipping sequence is one of a set of codes including non-inverse eleven-bit Barker code, an inverse of the Barker code and a reversed sequence of the inverse or non-inverse Barker code.
Claim 10
Dependent Claim
37 words
A system according to claim 7 wherein the eleven-bit Barker code has the non-inverse binary bit sequence 10110111000, the inverse sequence 01001000111, and the reversed sequences of the inverse and non-inverse code are 11100010010 and 00011101101, respectively.
Claim 11
Independent Claim
60 words
A system for receiving spread spectrum radio communication signals, including digital data signals, comprising: demodulator means for demodulating broadcast spread spectrum signals; de-spreader means employing single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence; and extractor means for extracting clock and data signals from the output of the de-spreader means.
Claim 12
Independent Claim
60 words
A system for receiving spread spectrum radio communication signals, including digital data signals, comprising: demodulator means for demodulating broadcast spread spectrum signals; de-spreader means employing single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence; and extractor means for extracting clock and data signals from the output of the de-spreader means.
Claim 13
Dependent Claim
25 words
A system according to claim 9 further including de-scrambler means for de-scrambling the extracted data to recover the digital data in a spread spectrum broadcast.
Claim 14
Independent Claim
90 words
A system for receiving spread spectrum radio communication signals, including digital data signals, comprising: demodulator means for demodulating broadcast spread spectrum signals; de-spreader means employing single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence; and extractor means for extracting clock and data signals from the output of the de-spreader means wherein the chipping sequence used by the de-spreader is the eleven-bit Barker code, an inverse of the eleven-bit Barker code, and reverse sequences of the inverse and non-inverse Barker code.
Claim 15
Independent Claim
90 words
A system for receiving spread spectrum radio communication signals, including digital data signals, comprising: demodulator means for demodulating broadcast spread spectrum signals; de-spreader means employing single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence; and extractor means for extracting clock and data signals from the output of the de-spreader means wherein the chipping sequence used by the de-spreader is the eleven-bit Barker code, an inverse of the eleven-bit Barker code, and reverse sequences of the inverse and non-inverse Barker code.
Claim 16
Independent Claim
128 words
A system for receiving spread spectrum radio communication signals, including digital data signals, comprising: demodulator means for demodulating broadcast spread spectrum signals; de-spreader means employing single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence; and extractor means for extracting clock and data signals from the output of the de-spreader means, wherein the de-spreader means further includes; means for digitally over-sampling and delaying a demodulated signal to create blocks of over-sampled data for each binary data bit of the demodulated signal; means for digitally multiplying the blocks over-sampled data with the pseudo-random chipping sequence; means for digitally summing the blocks of multiplied, over-sampled data into a summation value; and, means for digitally comparing the summation value with predetermined thresholds.
Claim 17
Independent Claim
128 words
A system for receiving spread spectrum radio communication signals, including digital data signals, comprising: demodulator means for demodulating broadcast spread spectrum signals; de-spreader means employing single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence; and extractor means for extracting clock and data signals from the output of the de-spreader means, wherein the de-spreader means further includes; means for digitally over-sampling and delaying a demodulated signal to create blocks of over-sampled data for each binary data bit of the demodulated signal; means for digitally multiplying the blocks over-sampled data with the pseudo-random chipping sequence; means for digitally summing the blocks of multiplied, over-sampled data into a summation value; and, means for digitally comparing the summation value with predetermined thresholds.
Claim 18
Dependent Claim
37 words
A system according to claim 12 wherein the chipping sequence used by the de-spreader is the non-inverse eleven-bit Barker code, an inverse of the eleven-bit Barker code, and reversed sequences of the inverse and non-inverse Barker code.
Claim 19
Dependent Claim
20 words
A system according to claim 13 wherein the delay means includes a shift register for storing the oversampled demodulated signal.
Claim 20
Dependent Claim
65 words
A system according to claim 12, wherein the comparing means includes: a first digital comparator for producing an output signal indicative of whether the summation value is outside a window defined by a predetermined upper and lower threshold value; and, a second digital comparator for producing an output signal indicative of whether the summation value is lesser or greater than a predetermined midpoint threshold value.
Claim 21
Dependent Claim
40 words
A system according to claim 15 wherein the extractor means operates to produce a binary data signal from the second digital comparator output if the first digital comparator output signal indicates that the summation value is outside the predetermined thresholds.
Claim 22
Dependent Claim
42 words
A system according to claim 16 wherein the extractor means further operates to produce a binary data signal from the second digital comparator output even if the first digital comparator output indicates that the summation value is not outside the predetermined thresholds.
Claim 23
Dependent Claim
30 words
A system according to claim 17 further including a carrier detect means that uses the output of the first digital comparator for detecting the presence of a valid received signal.
Claim 24
Dependent Claim
94 words
A spread spectrum radio communication system, comprising: generator means for generating a pseudo-random chipping sequence; frequency spreader means for combining digital data with the pseudo-random chipping sequence to produce a spread spectrum signal; modulator means for modulating the spread spectrum signal for broadcasting over a predefined frequency band; demodulator means for demodulating broadcast spread spectrum signals; de-spreader means employing single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence; and extractor means for extracting clock and data signals from the output of the de-spreader means.
Claim 25
Dependent Claim
94 words
A spread spectrum radio communication system, comprising: generator means for generating a pseudo-random chipping sequence; frequency spreader means for combining digital data with the pseudo-random chipping sequence to produce a spread spectrum signal; modulator means for modulating the spread spectrum signal for broadcasting over a predefined frequency band; demodulator means for demodulating broadcast spread spectrum signals; de-spreader means employing single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence; and extractor means for extracting clock and data signals from the output of the de-spreader means.
Claim 26
Dependent Claim
129 words
A spread spectrum radio communication system, comprising: generator means for generating a pseudo-random chipping sequence; frequency spreader means for combining digital data with the pseudo-random chipping sequence to produce a spread spectrum signal; modulator means for modulating the spread spectrum signal for broadcasting over a predefined frequency band; demodulator means for demodulating broadcast spread spectrum signals; de-spreader means employing single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence; and extractor means for extracting clock and data signals from the output of the de-spreader means, wherein the pseudo-random chipping sequence is selected from a set of codes including a non-inverse eleven-bit Barker code, an inverse of the eleven-bit Barker code and reversed sequences of the inverse and non-inverse Barker code.
Claim 27
Dependent Claim
129 words
A spread spectrum radio communication system, comprising: generator means for generating a pseudo-random chipping sequence; frequency spreader means for combining digital data with the pseudo-random chipping sequence to produce a spread spectrum signal; modulator means for modulating the spread spectrum signal for broadcasting over a predefined frequency band; demodulator means for demodulating broadcast spread spectrum signals; de-spreader means employing single bit quantization and oversampling for digitally correlating the output of the demodulator means with a pseudo-random chipping sequence; and extractor means for extracting clock and data signals from the output of the de-spreader means, wherein the pseudo-random chipping sequence is selected from a set of codes including a non-inverse eleven-bit Barker code, an inverse of the eleven-bit Barker code and reversed sequences of the inverse and non-inverse Barker code.
Claim 28
Dependent Claim
25 words
A system according to claim 20 further including de-scrambler means for de-scrambling the extracted data to recover the digital data in a spread spectrum broadcast.
References Cited (Backward Citations)
US3980945A
Cited
US4797923A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-30 | 2003-07-01 | 2003-12-31 | $7700.00 | Window Closed / Lapsed |