Fast index assignment for balanced N-description scalar quantization

Summary form only given. We address the design of any number of balanced descriptions with multiple description scalar quantizers (MDSQ), using fast index assignment methods. Such systems proceed in two steps, scalar quantization and index assignment, that map the quantized value to an N-tuple of quantization indices, to be sent over N channels. We address the specific balanced scenario, where all descriptions have equal rates and where any subset of k out of N descriptions induces the same distortion. We propose two simple index assignment schemes for uniform sources, that are able to generate any number, N (greater than 2), of such balanced descriptions, at any coding rate. The case of Gaussian distributions is also addressed using companding.