An adaptive FEC-based packet loss recovery scheme using RZ turbo codes

Packet-level forward error correction (FEC) is a packet loss recovery technique which does not require retransmissions and allows packet delivery with bounded delay and controllable reliability. This makes packet-level FEC attractive in networks running real-time applications like video and audio streaming. Current packet level FEC schemes are either based on simple parity check codes or Reed-Solomon codes with erasure decoding, whereas this paper considers the application of more powerful turbo codes to recover from lost packets. In particular, we investigate the capability of a newly designed Return to Zero (RZ) turbo code to reduce the packet loss rate (PLR) between the source and the destination. In the proposed implementation of the RZ turbo code packet loss recovery scheme, when a packet is lost, a burst of erasures, i.e., lost bits, is introduced into the turbo code codeword, and these erasures are recovered using the soft-decision RZ turbo decoder. Because of the RZ interleaver, the RZ turbo decoder randomizes erasure positions and recovers them quite well. Our simulations indicate that the PLR performance of the proposed RZ turbo code packet loss recovery scheme benefits from adjusting the interleaver size to accommodate the changes in the raw link PLR.