Hybrid ARQ with ratio threshold combining for frequency-hop communication systems
Frederick J. Block, Carl W. Baum · 2002
In channels affected by strong interference, the throughput of frequency-hop spread-spectrum communication systems employing hybrid automatic repeat request protocols can be unacceptably low. We show that significant improvements in throughput can be achieved by combining symbols between the different transmissions. Several symbol combining techniques based on Viterbi's ratio threshold test are proposed and are shown to provide significant improvements in performance.