Lattice-ladder decorrelation filters developed for co-channel speech separation

The previously proposed lattice-ladder adaptive decorrelation filtering (LL-ADF) algorithm (Ken and Zhao 1999) is further studied and improved in this work, with the aim of developing a more efficient co-channel speech separation system. The effect of the joint linear predictions is first analyzed and the conversions between the lattice coefficients and the prediction and filter vectors are formulated. The implementation issues on the estimation of lattice coefficients are then discussed and the adaptation equations are further refined. Experimental results demonstrate the effectiveness of the algorithm in reducing cross-interference between co-channel speech sources as well as the significant performance improvement over the previous direct-form ADF algorithm. A simplified LL-ADF is also proposed as a compromise between computational cost and system performance