Patent ID: 8230299

Claim:
A digital communications transmitter interleaving LDPC encoded bits in a QPSK modulation system based on a rule: { b ~ i = b i - i ⁢ ⁢ mod ⁢ ⁢ 256 + ( i ⁢ ⁢ mod ⁢ ⁢ 8 ) × 32 + ⌊ i 8 ⌋ ⁢ mod ⁢ ⁢ 32 b ~ i + 1 = b ( i + 1 ) - ( i + 1 ) ⁢ ⁢ mod ⁢ ⁢ 256 + ( ( i ⁢ + 1 ) ⁢ ⁢ mod ⁢ ⁢ 8 ) × 32 + ⌊ i + 1 8 ⌋ ⁢ mod ⁢ ⁢ 32 , for iε{i|0≦i≦N ldpc — bits −1, and imod2=0}iε{i|0≦i≦N ldpc — bits −1, and imod2=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.