“…For studying m-quasi-cyclic codes, quite often [1,6,7,8,9,10,11,14,15,20,21,22,23,30] the co-ordinates of a codeword a = (a 0 , a 1 , · · · , a n−1 ) are permuted and blocked as ((a 0 , a m , a 2m , · · · , a ( n m −1)m ), (a 1 , a m+1 , a 2m+1 , · · · , a ( n m −1)m+1 ), · · · , (a m−1 , a 2m−1 , a 3m−1 , · · · , a n−1 )). With this co-ordinate ordering, the generator and parity check matrices (with possibly some redundant rows) can be written as matrices with n m × n m circulant matrices as elements.…”