We define the bidirectional distance profile (BDP) of a convolutional code as the minimum of the distance profiles of the code and its corresponding "reverse" code. We present tables of codes with the optimum BDP (OBDP), which minimize the average complexity of bidirectional sequential decoding algorithms. The computer search is accelerated by the facts that optimum distance profile (ODP) codes of larger memory must have ODP codes of smaller memory as their "prefixes", and that OBDP codes can be obtained by "concatenating" ODP and reverse ODP codes of smaller memory. We compare the performance of OBDP codes and other codes by simulation.

翻译：本文定义了卷积码的双向距离轮廓（BDP）为该码及其对应的“反向”码距离轮廓的最小值。我们列出了具有最优双向距离轮廓（OBDP）的码表，该类码能够最小化双向序列译码算法的平均复杂度。计算机搜索过程通过以下两个事实得以加速：较大记忆深度的最优距离轮廓（ODP）码必须以较小记忆深度的ODP码作为其“前缀”，且OBDP码可通过“级联”较小记忆深度的ODP码和反向ODP码获得。我们通过仿真比较了OBDP码与其他码的性能。