Firing the genie: Two-phase short-blocklength convolutional coding with feedback

In an effort to account for the latency cost of error detection at short blocklengths, we simulate a two-phase feedback-based incremental redundancy scheme. This scheme consists of communication and confirmation phases, as used in the error exponent literature, and allows messages to be decoded with high reliability. Simulation results of tail-biting convolutional codes on the AWGN channel are shown, which demonstrate that the two-phase scheme can deliver throughput surpassing the random coding lower bound on variable-length feedback (VLF) code achievability. A comparison with simulation of CRC-based error detection is also presented.