A COMMUNICATION SYSTEM HAVING BAD FRAME INDICATOR MEANS FOR RESYNCHRONIZATION PURPOSES

摘要

A communication system (1) comprises a transmitter (2), a receiver (3), and an up/down link communication channel (4, 6) arranged for data communication from the transmitter (2) through the up link communication channel (4) to the receiver (3). The communication system (1) is further arranged to feedback data from the receiver (3) through the down link communication channel (6) to the transmitter (2). The receiver (3) comprises a bad frame indicator (5) for providing a bad frame indication (BFI) upon receipt of a corrupted frame, which is present in synchronized data communicated over the up link communication channel (4); and the transmitter (2) comprises resynchronization means (7) coupled to the down link communication channel (6) for receiving BFI related data and in response thereto recommencing data communication over the up link communication channel (4), in accordance with a resynchronization procedure, which starts from a predetermined state. A fast acting feedback resynchronization procedure for a GSM speech system is presented which prevents substantial error propagation from occurring at the receiver end.