Adaptive forward error correction for fast data transmission over the mobile radio channel

The authors describe an adaptive forward error correction (AFEC) protocol in which the information symbols are sent first and subsequently more and more redundancy symbols are added until the receiver has enough symbols to correct the detected errors. Thus, the required redundancy is automatically adapted to the actual channel state. The AFEC works best with maximum distance separable codes, such as Reed-Solomon codes. The authors discuss the throughput and residual error rate performance of this method to facilitate a comparison with existing protocols. When AFEC is used in connection with a fixed-rate data source or communication network, buffers can be used to level out channel fluctuations. Two applications (the wideband CD 900 cellular digital mobile phone system and the pan-European GSM standard) are presented, verifying the efficiency of the proposed data transmission method