The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 19, 1994
Filed:
Sep. 21, 1984
Lars T Svensson, Eksatravagen, SE;
Telefonaktiebolaget LM Ericsson, Stockholm, SE;
Abstract
An arrangement for adjusting an adaptive digital balance filter included in a subscriber unit connected to a telephone line includes a selection unit, which can be connected to the subscriber unit either via the exchange or via a separately arranged switch. When the selection unit is connected to the subscriber unit, the balance filter is disconnected from both branches of the subscriber unit. A test signal generator is included in the selector unit for sending a signal on the lines via both branches of the subscriber unit. There is further included a plurality of digital filters wherein the transfer function of any of the filters closely coincides with the transfer function of the filter formed by the line impedance and the portion of the subscriber unit which is connected to the line and to the balance filter. By means of a measuring unit there is formed a criterion for determining which one of the filters included in the selector unit most closely matches the above-mentioned filter, and the parameters of the selected filter are allowed to determine the parameters of the balance filter.