US5144668A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal overlap detection in a communication system
Assignee: Motorola Solutions Inc
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Filing: 1991-01-25
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Granted: 1992-09-01
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Expires: 2011-01-25
Abstract
Abstract In frequency-hopping spread-spectrum systems, it is necessary to maintain frequency and bit synchronization (sync) between the transmitter and receiver in order to maintain quality data recovery at the receiver. Two transmissions in adjacent hop-time intervals may overlap because of various time delays within the system. Collision bits (203 and 207) are used to realign the transmitted messages in time. The base station (103) manufactures (401) the collision bits (203 and 207) and transmits them to the communication unit (101), which echoes back (503) the bits on its next transmission. If the bits received at the base station do not match the bits sent (407), the base station (103) initiates (409) collision maintenance such that the communication unit (101) can adjust its DPLL (331) to realign its transmissions in time.
Inventors
- 👤 Charles J. Malek
- 👤 James A. McDonald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:39
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/69; H04B1/713; H04B1/715; H04B1/7156; H04B2001/7154; H04B2001/71566
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
136 words
A method of communication in a communication system with a base station and communication unit that communicate digital information messages to each other, comprising the steps of: transmitting a first message frame of a first digital information message, said first message frame having a format comprising a first boundary, a second boundary, and at least a first signal overlap detection field; receiving said transmitted first message frame; transmitting said at least a second signal overlap detection field in a second message frame of a second digital information message; detecting a signal overlap by comparing said at least a second signal overlap detection field with said at least a first signal overlap detection field; and adjusting, responsive to said step of detecting, message frames subsequent to said second message frame in time to eliminate said signal overlap.
Claim 2
Independent Claim
136 words
A method of communication in a communication system with a base station and communication unit that communicate digital information messages to each other, comprising the steps of: transmitting a first message frame of a first digital information message, said first message frame having a format comprising a first boundary, a second boundary, and at least a first signal overlap detection field; receiving said transmitted first message frame; transmitting said at least a second signal overlap detection field in a second message frame of a second digital information message; detecting a signal overlap by comparing said at least a second signal overlap detection field with said at least a first signal overlap detection field; and adjusting, responsive to said step of detecting, message frames subsequent to said second message frame in time to eliminate said signal overlap.
Claim 3
Dependent Claim
27 words
The method of transmission of claim 1, wherein said at least a first signal overlap detection field appears closer to said first boundary than said second boundary.
Claim 4
Dependent Claim
27 words
The method of transmission of claim 1, wherein said at least a first signal overlap detection field appears closer to said second boundary than said first boundary.
Claim 5
Dependent Claim
26 words
The method of transmission of claim 1, wherein said at least a first signal overlap detection field is comprised of at least one pseudo-random digital bit.
Claim 6
Dependent Claim
38 words
The method of transmission of claim 1, further comprising the step of processing, responsive to said step of receiving, said at least a first signal overlap detection field into said at least a second signal overlap detection field.
Claim 7
Dependent Claim
135 words
A communication unit for use in a communication system with a base station and communication unit that communicate digital information messages to each other, the communication unit comprising: means for processing the digital information messages; means for receiving a first message frame of a first digital information message from the base station, said message frame having a format comprising a first boundary, a second boundary, at least a first signal overlap detection field, and frame alignment instructions; means, coupled to said means for processing, for transmitting a second message frame of a second digital information message, said second message frame having a format comprising at least a second signal overlap detection field; and means for executing said frame alignment instructions from the base station to time align message frames subsequent to said second message frame.
Claim 8
Dependent Claim
135 words
A communication unit for use in a communication system with a base station and communication unit that communicate digital information messages to each other, the communication unit comprising: means for processing the digital information messages; means for receiving a first message frame of a first digital information message from the base station, said message frame having a format comprising a first boundary, a second boundary, at least a first signal overlap detection field, and frame alignment instructions; means, coupled to said means for processing, for transmitting a second message frame of a second digital information message, said second message frame having a format comprising at least a second signal overlap detection field; and means for executing said frame alignment instructions from the base station to time align message frames subsequent to said second message frame.
Claim 9
Dependent Claim
26 words
The communication unit of claim 6, wherein said at least a first signal overlap detection field appears closer to said first boundary than said second boundary.
Claim 10
Dependent Claim
26 words
The communication unit of claim 6, wherein said at least a first signal overlap detection field appears closer to said second boundary than said first boundary.
Claim 11
Dependent Claim
24 words
The communication unit of claim 6, wherein said at least one signal overlap detection field is comprised of at least one pseudo-random digital bit.
Claim 12
Dependent Claim
30 words
The communication unit of claim 6, further comprising means for processing said at least a first signal overlap detection field into said at least a second signal overlap detection field.
Claim 13
Dependent Claim
13 words
The communication unit of claim 6, further comprising digital phase lock loop means.
Claim 14
Dependent Claim
23 words
The communication unit of claim 11, said means for executing further comprising means for advancing and retarding said digital phase lock loop means.
Claim 15
Dependent Claim
31 words
The communication unit of claim 11, wherein said means for executing further comprises means for effecting one of increasing and decreasing rate of operation of said digital phase lock loop means.
Claim 16
Independent Claim
133 words
A method of communication in a communication unit for use in a communication system with a base station and communication unit that communicate digital information to each other, comprising the steps of: processing the digital information messages; receiving a first message frame of a first digital information message from the base station, said message frame having a format comprising a first boundary, a second boundary, at least a first signal overlap detection field, and frame alignment instructions; transmitting, responsive to said steps of processing and receiving, a second message frame of a second digital information message, said second message frame having a format comprising at least a second signal overlap detection field; and executing said frame alignment instructions from the base station to time align message frames subsequent to said second message frame.
Claim 17
Independent Claim
133 words
A method of communication in a communication unit for use in a communication system with a base station and communication unit that communicate digital information to each other, comprising the steps of: processing the digital information messages; receiving a first message frame of a first digital information message from the base station, said message frame having a format comprising a first boundary, a second boundary, at least a first signal overlap detection field, and frame alignment instructions; transmitting, responsive to said steps of processing and receiving, a second message frame of a second digital information message, said second message frame having a format comprising at least a second signal overlap detection field; and executing said frame alignment instructions from the base station to time align message frames subsequent to said second message frame.
Claim 18
Dependent Claim
35 words
The method of communication of claim 14, wherein said transmitting step further comprises the step of formatting said at least a first signal overlap detection field closer to said first boundary than said second boundary.
Claim 19
Dependent Claim
35 words
The method of communication of claim 14, wherein said transmitting step further comprises the step of formatting said at least a first signal overlap detection field closer to said second boundary than said first boundary.
Claim 20
Dependent Claim
33 words
The method of communication of claim 14, wherein said transmitting step further comprises the step of formatting said at least a first signal overlap detection field with at least one pseudo-random digital bit.
Claim 21
Dependent Claim
38 words
The method of communication of claim 14, further comprising the step of processing, responsive to said step of receiving, said at least a first signal overlap detection field into said at least a second signal overlap detection field.
Claim 22
Dependent Claim
28 words
The method of communication of claim 14, wherein said step of executing further comprises the step of effecting one of advancing and retarding a digital phase lock loop.
Claim 23
Dependent Claim
32 words
The method of communication of claim 14, wherein said step of executing further comprises the step of effecting one of increasing and decreasing rate of operation of a digital phase lock loop.
Claim 24
Independent Claim
145 words
A method of communication in a base station for use in a communication system with a base station and communication unit that communicate digital information messages to each other, comprising the steps of: transmitting a first message frame of a first digital information message, said first message frame having a format comprising a first boundary, a second boundary, and at least a first signal overlap detection field; receiving a second message frame of a second digital information message, said second message frame having a format comprising at least a second signal overlap detection field; comparing said at least a first signal overlap detection field with said at least a second signal overlap detection field; and informing, responsive to said step of comparing, the communication unit to time align message frames subsequent to said second message frame with additional frame alignment instructions to eliminate signal overlap.
Claim 25
Independent Claim
145 words
A method of communication in a base station for use in a communication system with a base station and communication unit that communicate digital information messages to each other, comprising the steps of: transmitting a first message frame of a first digital information message, said first message frame having a format comprising a first boundary, a second boundary, and at least a first signal overlap detection field; receiving a second message frame of a second digital information message, said second message frame having a format comprising at least a second signal overlap detection field; comparing said at least a first signal overlap detection field with said at least a second signal overlap detection field; and informing, responsive to said step of comparing, the communication unit to time align message frames subsequent to said second message frame with additional frame alignment instructions to eliminate signal overlap.
Claim 26
Dependent Claim
35 words
The method of communication of claim 21, wherein said transmitting step further comprises the step of formatting said at least a first signal overlap detection field closer to said first boundary than said second boundary.
Claim 27
Dependent Claim
35 words
The method of communication of claim 21, wherein said transmitting step further comprises the step of formatting said at least a first signal overlap detection field closer to said second boundary than said first boundary.
Claim 28
Dependent Claim
36 words
The method of communication of claim 21, further comprising the step of effecting one of an increase and decrease of rate of operation of a digital phase lock loop in accordance with said frame alignment instructions.
Claim 29
Dependent Claim
33 words
The method of communication of claim 21, wherein said transmitting step further comprises the step of formatting said at least a first signal overlap detection field with at least one pseudo-random digital bit.
Claim 30
Dependent Claim
71 words
The method of communication of claim 25, wherein said step of comparing further comprises the steps of: matching said at least one pseudo-random digital bit of said at least a first signal overlap detection field with said at least one pseudo-random digital bit of said at least a second signal overlap detection field; and creating, responsive to said step of matching, frame alignment instructions to make forward and reverse alignment corrections.
Claim 31
Dependent Claim
147 words
A base station for use in a communication system with a base station and communication unit that communicate digital information to each other, the base station comprising: means for transmitting a first message frame of a first digital information message, said first message frame having a format comprising a first boundary, a second boundary, and at least a first signal overlap detection field; means for receiving a second message frame of a second digital information message, said second message frame having a format comprising at least a second signal overlap detection field; means for comparing said at least a first signal overlap detection field with said at least a second signal overlap detection field; and means, coupled to said means for comparing, for informing the communication unit to time align message frames subsequent to said second message frame with additional frame alignment instructions to eliminate signal overlap.
Claim 32
Dependent Claim
147 words
A base station for use in a communication system with a base station and communication unit that communicate digital information to each other, the base station comprising: means for transmitting a first message frame of a first digital information message, said first message frame having a format comprising a first boundary, a second boundary, and at least a first signal overlap detection field; means for receiving a second message frame of a second digital information message, said second message frame having a format comprising at least a second signal overlap detection field; means for comparing said at least a first signal overlap detection field with said at least a second signal overlap detection field; and means, coupled to said means for comparing, for informing the communication unit to time align message frames subsequent to said second message frame with additional frame alignment instructions to eliminate signal overlap.
Claim 33
Dependent Claim
26 words
The base station of claim 27, wherein said at least a first signal overlap detection field appears closer to said first boundary than said second boundary.
Claim 34
Dependent Claim
26 words
The base station of claim 27, wherein said at least a first signal overlap detection field appears closer to said second boundary than said first boundary.
Claim 35
Dependent Claim
38 words
The base station of claim 27, wherein the communication unit further comprises digital phase lock loop means, and said frame alignment instructions include instructions to increase and decrease rate of operation of said digital phase lock loop means.
Claim 36
Dependent Claim
25 words
The base station of claim 27, wherein said at least a first signal overlap detection field is comprised of at least one pseudo-random digital bit.
Claim 37
Dependent Claim
71 words
The base station of claim 31, wherein said means for comparing further comprises: means for matching said at least one pseudo-random digital bit of said at least a first signal overlap detection field with said at least one pseudo-random digital bit of said at least a second signal overlap detection field; and means, coupled to said means for matching, for creating frame alignment instructions to make forward and reverse alignment corrections.
Claim 38
Dependent Claim
31 words
The base station of claim 27, further comprising means for processing said at least a first signal overlap detection field to match said at least a second signal overlap detection field.
Claim 39
Dependent Claim
30 words
The base station of claim 27, further comprising means for echoing said at least a first signal overlap detection field into said at least a second signal overlap detection field.
Claim 40
Dependent Claim
39 words
The method of communication of claim 21, further comprising the step of processing, responsive to said step of receiving, said at least a first signal overlap detection field to match said at least a second signal overlap detection field.
Claim 41
Dependent Claim
38 words
The method of communication of claim 21, further comprising the step of echoing, responsive to said step of receiving, said at least a first signal overlap detection field into said at least a second signal overlap detection field.
Claim 42
Dependent Claim
38 words
The method of transmission of claim 1, further comprising the step of echoing, responsive to said step of receiving, said at least a first signal overlap detection field into said at least a second signal overlap detection field.
Claim 43
Dependent Claim
30 words
The communication unit of claim 6, further comprising means for echoing said at least a first signal overlap detection field into said at least a second signal overlap detection field.
Claim 44
Dependent Claim
38 words
The method of communication of claim 14, further comprising the step of echoing, responsive to said step of receiving, said at least a first signal overlap detection field into said at least a second signal overlap detection field.
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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) | 1995-09-01 | 1996-03-02 | 1996-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-01 | 2000-03-02 | 2000-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-01 | 2004-03-02 | 2004-09-01 | $7700.00 | Window Closed / Lapsed |