The performance of zero forcing DSL systems

DSL systems use multi-channel processing to mitigate the electromagnetic coupling between the wires in a binder and provide high data rates to multiple users. In recent years, most multichannel processing for DSL had focused on zero-forcing (ZF) processing that was proven to be near optimal. This near optimality has been observed in numerical evaluations as well as in real life systems. However, this near optimality has only been demonstrated theoretically by relatively loose bounds. In this paper we prove novel bounds on the performance of ZF processing in DSL systems. These bounds are simpler and yet tighter than currently known bounds. These novel bounds support previously published results, and further confirm the near optimality of ZF processing.