Digital encoder and decoder synchronization in the presence of late arriving packets

摘要

In a speech signal being reconstructed from digital samples, artificial gaps caused by discarded late packets are minimized by holding state varibales constant in a decoder used to reconstruct the speech signal. The decoder state variables are held constant from the end of the last previous packet information field for up to a prescribed interval. Upon arrival of the "late" packet, the decoder passes from the hold variables state to its normal operating state and reading out of samples from the packet information field is initiated immediately. Subsequent packets in the information spurt are concatenated to the late arriving packet.