In this paper, we first introduce the concept of elementary linear subspace, which has similar properties to those of a set of coordinates. Using this new concept, we derive properties of maximum rank distance (MRD) codes that parallel those of maximum distance separable (MDS) codes. Using these properties, we show that the decoder error probability of MRD codes with error correction capability t decreases exponentially with t2 based on the assumption that all errors with the same rank are equally likely. We argue that the channel based on this assumption is an approximation of a channel corrupted by crisscross errors.
I. INTRODUCTIONThe Hamming metric has often been considered the most relevant metric for error-control codes so far. Recently, the rank metric [1] has attracted some attention due to its relevance to space-time coding [2] and storage applications [3]. In [4], space-time block codes with good rank properties have been proposed. Rank metric codes are used to correct crisscross errors that can be found in memory chip arrays and magnetic tapes [3]. Rank metric codes have been used in public-key cryptosystems as well [5].In [1], a Singleton bound on the minimum rank distance of rank metric codes was established, and codes that attain this bound were called maximum rank distance (MRD) codes. An explicit construction of MRD codes (these codes are referred to as Gabidulin codes) was also given in [1], and this construction was extended in [6]. Also, a decoding algorithm that parallels the extended Euclidean algorithm (EEA) was proposed for MRD codes.In this paper, we investigate the performance of MRD codes when used to protect data from additive errors based on two assumptions. First, we assume all errors with the same rank are equally likely. We argue that the channel based on this assumption is an approximation of a channel corrupted by crisscross errors (see Section IV for details). Second, we assume that a bounded rank distance decoder is used, with error correction capability t. If the error has rank no more than t, the decoder gives the correct codeword. When the error