Crosstalk Identification in xDSL Systems with Unknown Model Orders

Crosstalk between multiple services transmitting through the same telephone cable is the primary limitation to digital subscriber line services. From a spectrum management point of view, it is important to have an accurate map of all the services that generate crosstalk into a given pair. This paper on crosstalk identification is motivated by practical consideration that the model order of the crosstalk function is generally unknown. A recursive algorithm for multi-channel FIR xDSL systems is proposed to identify the crosstalk model order and parameters simultaneously. The most appropriate model order is then determined by examination of the cost functions. The recursive formulae for the cost function and the parameter estimate are derived, which greatly improves the computational efficiency. The simulation results show the effectiveness of the proposed algorithm.