Two Novel Classes of Fast Partial Crosstalk Cancellers for DSL

Line selection (LS), tone selection (TS), and joint tone-line selection (JTLS) partial crosstalk cancellers have been proposed to reduce the online computational complexity of far-end crosstalk (FEXT) cancellers in DMT DSL. However, in contrast to perfect crosstalk cancellers, partial crosstalk cancellers should also provide a low pre-processing complexity when crosstalk profile changes rapidly in time. In this paper, we propose two novel fast classes of JTLS algorithms, namely, a family of sub-sort JTLS algorithms and the Lagrange JTLS. The computational complexity of our algorithms is much lower than that of the optimal greedy algorithm. Simulation results show that the performances of the proposed sub-sort algorithms are very close to the optimal greedy algorithm. More importantly, our Lagrange JTLS algorithm is optimal for the DSL channels we consider.