Patent ID: 6934385
Filing Date: 2005-08-23
Classification: H04B

Abstract:
1. An apparatus of a digital echo canceller that is suitable to use on a full-duplex digital echo transceiver and is used to cancel a produced echo signal, the apparatus comprises: a plurality of first-set delay circuits installed, wherein each delay circuit has an input and an output, and are all connected in series, and the first input receives an input signal that transmitted from the full-duplex digital transceiver, and the first-set delay circuits are arranged in groups and each group has N delay circuits; a selector with an input and an output, wherein the input is based on an exhaustive search that chooses to connect to one the outputs of the first delay circuits; a plurality of second-set delay circuits, wherein each circuit has an input and an output and are all connected in series, and the first input is connected to the output of the selector; a plurality of multipliers wherein the number of the multipliers is the same as the number of the second-set delay circuits, and the multipliers are connected respectively to the outputs of the second-set delay circuits, and the transmitting signals from the second-set delay circuits are multiplied respectively to correlation coefficients; an adder that adds the results from the multiplication operation together to produce an estimated echo signal, wherein the estimated echo signal cancels the echo signal.