PURPOSE: To provide the code book address detecting method which enables detection in a short time.
CONSTITUTION: This method is provided with a code book 1 successively arranging (n) kinds of white noise sequences from the small power value of a vector constant and a power value/address correspondence table 4 having the power values of the vector constants of the white noise sequences corresponding to the addresses of the code book 1, and a power calculation part 5 calculates the power value of an input voice vector. Then, the calculated value is inputted to a linear predictor 6, the power value of the next input voice vector is predicted, and the address of the power value most approximated to this predicted power value is calculated from the power value/address correspondence table by an approximate power value address detection part 7. In a minimum differential power address detection part 3, the address of the code book 1 storing the vector constant of the white noise sequence to minimize difference between output power driving a synthesizing filter 2 and the power of the next inputted input voice vector is detected while successively reading the vector constants of the white noise sequences adjacent to the address detected by the address detection part 7 from the code book 1.
SON GETSUEI
NISHIYAMA KENJI
