Patent ID: 8028219

Claim:
A digital communications transmitter interleaving LDPC encoded bits in a 16APSK modulation system based on a rule: { b ~ i = b ( 8 × ⌊ i 1024 ⌋ + N offset + i 4 ⁢ mod ⁢ ⁢ 8 ) × 32 + ⌊ i 32 ⌋ ⁢ mod ⁢ ⁢ 32 b ~ i + 1 = b ( 8 × ⌊ i 1024 ⌋ + N offset + i 4 ⁢ mod ⁢ ⁢ 8 + 120 ) × 32 + ⌊ i 32 ⌋ ⁢ mod ⁢ ⁢ 32 b ~ i + 2 = b ( 8 × ⌊ i 1024 ⌋ + N offset + i 4 ⁢ mod ⁢ ⁢ 8 + 240 ) × 32 + ⌊ i 32 ⌋ ⁢ mod ⁢ ⁢ 32 b ~ i + 3 = b ( i 4 + 32 × N offset + 11520 ) ⁢ mod ⁢ ⁢ N ldpc_bits - ( i 4 ) ⁢ mod ⁢ ⁢ 256 + ( i 4 ⁢ mod ⁢ ⁢ 8 ) × 32 + ⌊ i 32 ⌋ ⁢ mod ⁢ ⁢ 32 for iε{i|0≦i≦N idpc — bits −1, and i mod 4=0}, where └x┘ is the floor function which returns the largest integer that is less than or equal to x, N ldpc — bits =15360 is the codeword length of the LDPC code in use, and N Offset is the offset values for different code rates which are defined as: Rate N offset 2/3 80 3/4 88 4/5 96 5/6 104 13/15 112 9/10 120.