We analyze the throughput achievable by a truncated Hybrid ARQ protocol (HARQ) using
incremental redundancy (IR) when transmitting over a block-fading channel whose state is
unknown at the transmit end. We allow the transmission rates to vary, optimize them, and
show that such a variable-rate HARQ-IR provides gains with respect to a fixed-rate
transmission in terms of increased throughput and decreased average number of
transmissions.

The throughput achievable in truncated Hybrid ARQ protocol (HARQ) using incremental
redundancy (IR) in analyzed when transmitting over a block-fading channel whose state is
unknown at the transmitter. We allow the transmission lengths to vary, optimize them
efficiently via dynamic programming, and show that such a variable-rate HARQ-IR provides
gains with respect to a fixed-rate transmission in terms of increased throughput and
decreased average number of transmissions, reducing at the same time the outage …