Multimode precoding for crosstalk mitigation in ultra‐broadband DSL systems

摘要

The achievable downstream bit-rate performance of digital subscriber line (DSL) channels using low-complexity linear precoders is suboptimal when the row-wise diagonally dominant property of the channel matrix does not hold at high frequencies anticipated to be exploited in future-generation DSL systems, while the optimal nonlinear precoder is computationally demanding. In this paper, we propose two multimode precoders, which are operable in four modes on each tone. Specifically, the proposed precoding strategies exploit the insertion loss and crosstalk information inferred from the channel matrix to execute mode selection for all the transmission tones. The computational complexity of the proposed multimode precoders is derived and compared with existing precoders. Simulation results show that the proposed precoders can achieve near-optimal performance at a lower computational complexity.