中文说明： 在很多实际通信的信道中，出现的差错既不是单纯随机独立的也不是明显的单个突发差错，而是混合型差错，为了对付这类混合差错，采用仅能纠正随机独立差错或纠正单个突发差错的码都不太合适。因此，希望能设计一类既能纠随机独立错误，又能纠单个或多个突发差错的码。交错码、级连码、乘积码均属于这类纠错码，其中，性能最好、最为有效、也最常采用的是级连码。 突发性错误下，级联码的误码性能
English Description：
In many practical communication channels, the error is neither random independent nor obvious single burst error, but mixed error. In order to deal with this kind of mixed error, it is not suitable to use the code which can only correct random independent error or single burst error. Therefore, we hope to design a class of codes which can correct both random independent errors and single or multiple burst errors. Interleaved codes, concatenated codes and product codes all belong to this kind of error correcting codes. Among them, concatenated codes are the most efficient and often used ones.