Multiple-scale leader-lattice VQ with application to LSF quantization

• Published in: Signal processing Vol. 82; no. 4; pp. 563 - 586
• Main Authors: Vasilache, Adriana, Dumitrescu, Bogdan, Tăbuş, Ioan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2002; Elsevier Science
• Subjects: Applied sciences; Exact sciences and technology; Information, signal and communications theory; Lattice quantization; LSF quantization; NN search; Sampling, quantization; Signal and communications theory; Structured VQ; Telecommunications and information theory; Lattice quantization; Structured VQ; LSF quantization; NN search; Nearest neighbour; Experimental result; Vector quantization; Multiscale method; Signal processing; Lattice structure; Search algorithm
• ISSN: 0165-1684; 1872-7557
• DOI: 10.1016/S0165-1684(01)00205-5

In this study we introduce two new quantization structures, namely the multiple scale leader-lattice vector quantization (MSLLVQ) using different lattice truncations and (MSLLVQ) using different unions of leader vectors. The design methods and the corresponding encoding algorithms are presented for each structure. We first focus on the search in a truncated lattice and in a leader class of a lattice and we then propose two new search methods for pyramidal ( l 1-) truncations and l 1/2-truncations. The encoding algorithms have low memory and computational requirements. The new schemes outperform in terms of SNR other lattice quantization structures presented in the literature in the case of generalized Gaussian source densities with decay parameters 0.5, 1 and 2. In addition, when used for LSF quantization they can achieve a mean spectral distortion below 1 dB at only 19 bits, being superior to the G.729 speech coder.