Flexible Multiple Description Lattice Vector Quantizer with L ≥ 3 Descriptions

In previous work on multiple description lattice vector quantizers (MDLVQ) with L ≥ 3 descriptions, once the central and side lattice codebooks are fixed, the decoding quality is determined for all numbers k of received descriptions. Therefore, it is not possible to achieve tradeoffs between the quality of reconstruction for different values of k, 1 ≤ k ≤ L - 1. This work proposes a flexible MDLVQ capable of overcoming the above drawback. For this, a different reconstruction method is employed and a heuristic index assignment algorithm, which uses L - 2 parameters to control the distortions for 2 ≤ k ≤ L - 1, is developed. The second contribution of this work is a structured index assignment for the case L = 3 and the derivation of asymptotical expressions of the distortions at high resolution. The proposed index assignment has a simple mechanism for controlling the tradeoff between the reconstruction quality when k = 1 and when k = 2, and is able to achieve a wide range of distortion values.