Efficient indexing method for lattice quantization applications

Indexing the codevectors is a key problem in lattice quantization applications. We propose a method based on the idea of a coding table encompassing a set of points chosen as small as possible and called the fundamental region. Our method works for both spherical and pyramidal codebooks. It provides a good tradeoff between computational complexity and storage requirements. Finally, it improves of 3 dB on the signal-to-noise ratio of the LBG algorithm at a given memory cost.