A DCT-based fast signal subspace technique for robust speech recognition
Jun Huang, Yunxin Zhao · IEEE Transactions on Speech and Audio Processing · 2000
In this correspondence, a fast computational method is proposed to approximate the Karhunen-Loeve transform (KLT) for the covariance matrix of the autoregressive process. A fast algorithm which reduces the computation of eigenvalues of an N/spl times/N symmetric Toeplitz matrix from O(N/sup 3/) in KLT to N/sup 2/ is further developed. Experimental results demonstrate that the performance of the fast algorithm is very close to the KLT in eigenvalue computation and in energy constrained signal subspace speech enhancement for speech recognition in a car environment.