  This paper presents a variable-length decision-feedback scheme that uses
tail-biting convolutional codes and the tail-biting Reliability-Output Viterbi
Algoritm (ROVA). Comparing with recent results in finite-blocklength
information theory, simulation results for both the BSC and the AWGN channel
show that the decision-feedback scheme using ROVA can surpass the random-coding
lower bound on throughput for feedback codes at average blocklengths less than
100 symbols. This paper explores ROVA-based decision feedback both with
decoding after every symbol and with decoding limited to a small number of
increments. The performance of the reliability-based stopping rule with the
ROVA is compared to retransmission decisions based on CRCs. For short
blocklengths where the latency overhead of the CRC bits is severe, the
ROVA-based approach delivers superior rates.
