a. (D -1)(i mod N) symbols, wherein gcd(N, D)=1; b. (N) (i mod D) symbols, wherein D|N; C. (D - 1)((N-i-1) mod N) symbols, wherein gcd(N,D)=1; and d. (N)((D-i-1) mod D) symbols, wherein D|N; wherein D is a predetermined interleave depth, and N is a predetermined memory block length. 6.