A great deal of research effort has been expended in the design and construction of structured low-density parity-check (LDPC) codes.In this paper

we propose a method to construct structured LDPC codes based on maximum-distance separable (MDS) codes.The main idea of this paper is to expand the method which is based on RS codes with two information symbols

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to all MDS codes.The details of the method are described by using MDS convolutional codes to construct LDPC codes.Since the definition of the MDS convolutional codes are different from that of linear block codes

a shorten technology is used and proved in the paper.Some LDPC codes based on the proposed method with variable code length at high rates are constructed and simulation results show their performance advantage over random construction.