摘要 |
An xDSL modem having an adaptively adjustable guard band comprising a finite number of spaced-apart frequency bins between the upstream and downstream frequencies. The guard band is adjusted by selecting one from among a plurality of filters belonging to a filter bank of the receiver circuitry. A weighted loss in data capacity is calculated when each of the candidate filters are used, and the filter which gives the lowest loss in data capacity, subject to certain criteria, is used. The adjustment is made pursuant to noise and signal characteristics measured during start or restart of an xDSL communications session.
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