This work investigates the structure of rank-metric codes in connection with concepts from finite geometry, most notably the $q$-analogues of projective systems and blocking sets. We also illustrate how to associate a classical Hamming-metric code to a rank-metric one, in such a way that various rank-metric properties naturally translate into the homonymous Hamming-metric notions under this correspondence. The most interesting applications of our results lie in the theory of minimal rank-metric codes, which we introduce and study from several angles. Our main contributions are bounds for the parameters of a minimal rank-metric codes, a general existence result based on a combinatorial argument, and an explicit code construction for some parameter sets that uses the notion of a scattered linear set. Throughout the paper we also show and comment on curious analogies/divergences between the theories of error-correcting codes in the rank and in the Hamming metric.
翻译:这项工作调查了与有限几何概念有关的分级代码的结构,其中最突出的是投影系统和屏蔽装置的美元比方。我们还举例说明了如何将古典模拟代码与分级代码联系起来,使各种分级属性自然地转化成该对应法下的同质模拟概念。我们最有趣的结果应用在于最低分级代码理论,我们从几个角度介绍和研究这种理论。我们的主要贡献在于最低分级代码参数的界限,基于组合参数的一般存在结果,以及使用分散线性集概念的一些参数集的明确代码构建。我们在整个论文中还展示并评论了等级和Hamming指标中错误校正代码理论之间的奇怪相似/差异。