Forward Error Correction (FEC) is used ubiquitously in the communication pipeline. We explore noncooperative decoding where we aim to recover the code rate of a linear block code. We present a metric to characterize the quality of the code rate recovery which uses any rank based estimation technique. We derive a closed form expression for this metric in terms of the algorithmic and the environmental parameters and assert that it should be low for good recovery. We use this metric to derive an expression for a better code rate estimate in high noise conditions and compare it with existing estimates. Finally we validate the derived expression for the metric and the improved performance in the code rate estimate by simulating the recovery of a Low Density Parity Check (LDPC) code. This also enables us to derive the optimal algorithmic parameters for recovery.

翻译：前向纠错（FEC）在通信链路中无处不在。本文研究非合作解码场景，旨在恢复线性分组码的码率。我们提出一种度量，用于表征采用任何基于秩的估计技术的码率恢复质量。我们推导了该度量关于算法参数和环境参数的闭式表达式，并指出良好的恢复应使该度量值较低。利用该度量，我们推导了高噪声条件下更优码率估计的表达式，并与现有估计方法进行了比较。最后，通过模拟低密度奇偶校验（LDPC）码的恢复过程，我们验证了所推导的度量表达式以及码率估计性能的提升。这也使我们能够推导出恢复所需的最优算法参数。