Overload vector quantisation by selective shell projection in lattice VQ

An efficient overload vector quantisation algorithm is proposed for lattice vector quantisation (LVQ). It selects a projection shell for each overload vector by changing its scaled position along the radial direction to the origin in the truncated lattice and obtains the adjusted overload scaling factor for dequantisation from the orthogonality principle. Experimental results show that this algorithm achieves a good performance in signal to quantisation noise ratio (SQNR) over the conventional algorithm using a single projection of the overload vector on the external shell