Patent ID: 6757383
Filing Date: 2004-06-29
Classification: H04B

Abstract:
A cable balance network for echo-cancelling in a full-duplex telecommunication system incorporating a full-duplex port, at least one half-duplex port, and a full-duplex to half-duplex conversion circuit, said cable balance network comprising:(a) a first plurality n of resistors Rn, each of said resistors Rn having a fixed resistance value dependent upon the impedance connected to said full-duplex port, and each of said resistors Rn, having a positive node and a negative node; (b) a second plurality nâˆ’1 of capacitors Cnâˆ’1, each of said capacitors Cnâˆ’1having a fixed capacitance value dependent upon the impedance connected to said full-duplex port, and each of said capacitors Cnâˆ’1having a positive and a negative node; and (c) a circuit configuration comprising at least one pair of said first plurality of resistors and at least one of said second plurality of capacitors, such that the negative nodes of each of said resistors are effectively connected together, and such that each of said capacitors is connected between the positive nodes of a respective pair of said resistors; the circuit configuration being so constructed and arranged that said resistance values and capacitance values define an optimized cable balance network input impedance and an optimized transhybrid loss for said conversion circuit.