Patent ID: 6195337
Filing Date: 2001-02-27
Classification: H04L,H04W

Abstract:
An encoding mode control method in a digital cellular radio communication system having traffic channels, at least one of which are associated with a set of encoding modes, each mode having a different mix of speech encoder bit rate and data protection bit rate but the same total available gross bit rate, the method comprising:determining a first measure of the local radio environment at a transmitting end of a first link;selecting, at the transmitting end, a transmitter encoding mode from the set that at least partially depends on the first measure;transmitting in the selected transmitter encoding mode to the receiving end of the first link;trial decoding, at the receiving end, the received signal in several receiver decoding modes corresponding to the transmitter encoding modes;selecting, at the receiving end, the receiver decoding mode that is most likely to give the best decoded speech quality as the current receiver decoding mode;selecting, at the receiving end, a receiver encoding mode from the set that at least partially depends on the selected receiver decoding mode; andtransmitting, from the receiving end, in the selected receiver encoding mode on a second link using another such channel from the receiving end to said transmitting end.