SYNNETRIC VECTOR QUANTIZER

PURPOSE:To quickly generate a set of general-purpose output vectors and to reduce the capacity of a code book memory by giving a method which quickly generates a new more efficient tree for output vectors with symmetric structures in a multidimensional signal space and giving a circuit realizing said method. CONSTITUTION:An encoding part in a vector quantizer has a normalizing circuit 2 normalizing blocked input signal strings 2 and 1 every block, a normalizing constant 3, a normalized signal string(input vector) 4, a tree retrieval vector quantizer 5 and a code table update part 6. The encoding part has also a code table 7 generated in the code table update part, a vector quantizing index 8, a multiencoding part 9 which multiplexes the code table 7, the normalizing constant 3 and the index 7 and encodes a transmission line. The code table update part 6 is constituted of a vector memory 11 accumulating input vectors as a training string and a training string 12.