Signal overlap detection in a communication system
First Claim
1. 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.
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Accused Products
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.
93 Citations
39 Claims
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1. 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:
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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. - View Dependent Claims (2, 3, 4, 5, 37)
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6. 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:
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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. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 38)
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14. 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:
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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. - View Dependent Claims (15, 16, 17, 18, 19, 20, 39)
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21. 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:
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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. - View Dependent Claims (22, 23, 24, 25, 26, 35, 36)
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27. 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:
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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. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34)
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Specification