Superframe alignment to a pre-existing ADSL data exchange
First Claim
1. A method of identifying a superframe boundary comprising:
- summing data vectors for each symbol in a plurality of superframes;
determining the summed data vector having the largest magnitude; and
indicating the superframe boundary at the symbol position correlating to the largest summed data vector.
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Accused Products
Abstract
A digital subscriber line network allows a plurality of remote modems to communicate without interfering with the communication to the central office. Each symbol of a superframe is converted to a tone vector, and the tone vectors are integrated over a plurality of superframes. The tone vectors of the data symbols are random, and tend to cancel each other out. The tone vector of the synchronization symbol remains constant among the plurality of superframes, and the sum of these tone vectors over a plurality of superframes becomes large. By identifying the largest integrated tone vectors, the network may identify the position of the synchronization symbol. The modems may then align using the position of the synchronization symbol.
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Citations
20 Claims
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1. A method of identifying a superframe boundary comprising:
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summing data vectors for each symbol in a plurality of superframes;
determining the summed data vector having the largest magnitude; and
indicating the superframe boundary at the symbol position correlating to the largest summed data vector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of aligning modems comprising:
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identifying the position of a synchronization symbol in a superframe; and
aligning the symbols of each modem based on the position of the synchronization symbol. - View Dependent Claims (10, 11, 12, 13, 15, 16, 17, 18, 19, 20)
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14. A communication system comprising:
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a plurality of modems which communicate using a plurality of superframes, each of the plurality of superframes having a plurality of symbols; and
a synchronizer which identifies the position of the superframe boundary, wherein the plurality of modems align based on the superframe boundary.
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Specification