Patent ID: 7483528
Filing Date: 2009-01-27
Classification: H04L,H04M

Abstract:
1. A system for improving transmission of digital subscriber line (DSL) signals over a local loop, the system comprising: a loop extender capacitively coupled to the local loop, the loop extender comprising: at least one additional upstream filter and amplifying element coupled in parallel to the first upstream filter and amplifying element; at least one additional downstream filter and amplifying element coupled in parallel to the first downstream filter and amplifying element; a first transformer coupled to the plurality of upstream complex impedances, a first inverting buffer, and either the first downstream filter and amplifying element or one of the at least one additional downstream filter and amplifying elements via a third switch to couple the plurality of upstream complex impedances, the first inverting buffer, and either the first downstream filter and amplifying element or one of the at least one additional downstream filter and amplifying elements via the third switch to the local loop; and a second transformer coupled to the plurality of downstream complex impedances, a second inverting buffer, and either the first upstream filter and amplifying element or one of the at least one additional upstream filter and amplifying elements via a fourth switch to couple the plurality of downstream complex impedances, the second inverting buffer, and either the first upstream filter and amplifying element or one of the at least one additional upstream filter and amplifying elements via the fourth switch to the local loop.