Introduction.

The article discusses the basic concepts of error correcting codes. All error correcting codes are based on the same basic principle: Redundancy is added to information in order to correct any errors that may occur in the process of storage or transmission. In simple ECC scheme, the redundant symbols are appended to information symbols to obtain a coded sequence or codeword. According to the process of addition of redundancy, ECC can be divided into two classes: block and convolutional. These coding schemes are used in several applications as wireless communications, space communications, computer networks and many others.