A METHOD TO EVALUATE THE HANGOVER PERIOD IN A SPEECH DECODER IN DISCONTINUOUS TRANSMISSION, AND A SPEECH ENCODER AND A TRANSCEIVER

摘要

The invention relates to a method for mutual synchronization of thetransmitter's speech encoder and the receiver's speech decoder in acommunication system utilizing discontinuous transmitter between thetransmitter and the receiver. The discontinuous transmission comprisestemporally sequential frame periods of which some periods will containtransmitted frames and some periods contain no transmission; whereby themethod contains steps to generate information transmission periods (200)comprising at least one frame and containing information given by a user tosaid transmitter device, and silence periods (208, 209) having a length of atleast one frame period and containing other information than that given by theuser. The discontinuous transmission further comprises an irregularlyoccurring period (T) comprising at least one frame between the informationtransmission period (200) and the next silence period (208, 209), theirregular period forming a hangover period to determine the informationrelating to the silence period. In the method according to the invention thenumber of frame periods is counted in the receiver until a certain moment; thebeginning of said silence period (208, 209) is detected; and based on saidcounted number of frame periods and the beginning of the silence period (208,209) it is decided whether or not there is a hangover period (T) of said typebetween said information transmission period (200) and the silence period(208) following the information transmission period.