METHOD AND DEVICE FOR SEARCHING CODE DIRECTORY TO ENCODE VOICE SIGNAL, AND CELLULAR COMMUNICATION SYSTEM Russian patent published in 1999 - IPC

FIELD: communication. SUBSTANCE: method involves searching in code directory, which has multiple combination of amplitudes and pulse positions, each of which determines L different positions and has zero amplitude pulses and non-zero amplitude pulses, which are assigned to respective combination positions p=1, 2, ... L. Each non-zero amplitude pulse assumes existence of at least one of Q possible amplitudes. Goal of invention is achieved by preliminary selection of subset of combinations of amplitudes and pulse positions from code directory according to voice signal and searching only this subset of combinations. Preliminary selection of subset involves setting functional dependence Sp between respective positions p=1, 2, ... L and Q possible amplitudes. Search is restricted to those combinations of non-zero amplitude pulses from code directory that correspond to preliminary specified functional dependence. Functional dependence is established by preliminary assignment of one of Q possible amplitudes to each position p. Respective preliminary specified functional dependence is effective when each pulse of non-zero amplitude has amplitude Sp corresponding to preliminary assigned position p for this pulse. EFFECT: decreased search complexity. 27 cl, 7 dwg