US Patent 6977888 Hybrid ARQ for packet data transmission

A hybrid ARQ scheme is used incremental data packet combining. In an example embodiment, the hybrid ARQ scheme with incremental data packet combining employs three feedback signaling commands: ACK, NACK, and LOST. Using these three feedback commands, the hybrid ARQ scheme with incremental data packet combining provides both robustness and good performance. This scheme is particularly advantageous in communication systems with unreliable communication channels, e.g., a fading radio channel, where forward error correction (FEC) codes are used and some of the code symbols are more important than other code symbols. Benefits include increased throughput and decreased delay of the packet data communication.