Abstract:We consider linear cyclic codes with the locality property or locally recoverable codes (LRC codes). A family of LRC codes that generalises the classical construction of Reed-Solomon codes was constructed in a recent paper by Tamo and Barg (IEEE Transactions on Information Theory, No. 8, 2014). In this paper, we focus on distance-optimal cyclic codes that arise from this construction. We give a characterisation of these codes in terms of their zeros and observe that there are many equivalent ways of constructing optimal cyclic LRC codes over a given field. We also study subfield subcodes of cyclic LRC codes (BCH-like LRC codes) and establish several results about their locality and minimum distance. The locality parameter of a cyclic code is related to the Copyright c 2016 Inderscience Enterprises Ltd.
346
I. Tamo et al.dual distance of this code, and we phrase our results in terms of upper bounds on the dual distance.Keywords: cyclic LRC codes; irreducible cyclic codes; subfield subcodes; zeros of the code.Reference to this paper should be made as follows: Tamo, I., Barg, A., Goparaju, S. and Calderbank, R. (2016) Mathematics at Princeton University, and before that he was Vice President for Research at AT&T. Innovations by him are incorporated in a progression of voiceband modem standards that moved communications practice close to the Shannon limit. Together with Peter Shor and colleagues at AT&T Labs, he showed that good quantum error correcting codes exist and developed the group theoretic framework for quantum error correction. He is a co-inventor of space-time codes for wireless communication, where correlation of signals across different transmit antennas leads to reliable transmission. This paper is a revised and expanded version of a paper entitled 'Cyclic LRC codes and their subfield subcodes', presented at