Patent ID: 7293217

Claim:
In a communications system employing a plurality of rate matching stages for processing a plurality of individual parity bit streams derived through puncturing a selected number of bits, a method of avoiding problematic Turbo code puncturing patterns, the method comprising: (a) determining whether or not a desired code rate, used to process the parity bit streams, results in a problematic puncturing pattern; (b) if a problematic puncturing pattern results in step (a), adjusting the number of bits punctured in each of the parity bit streams by increasing the number of bits punctured in one of the parity bit streams and decreasing the number of bits punctured in another one of the parity bit streams; (c) determining a number of bits {circumflex over (N)} using N ^ = ⌊ 4 ⁢ I 7 ⁢ P + 1 2 ⌋ wherein I is the number of bits at the input to each branch of rate matching and P is the total number of the P 1 and P 2 bits at the output of rate matching; (d)if  I ( P / 2 ) - 7 ⁢ N ^ 2  < 1 - N ^ 2 + ⌊ N ^ 2 ⌋ , calculating the bias Δ = ⌈ max ⁢ { I ⌊ 7 ⁢ N ^ - 1 2 ⌋ - P 2 , P 2 - I ⌈ 7 ⁢ N ^ + 1 2 ⌉ } ⌉ ; and (e) setting Δ = 0 ⁢ ⁢ if ⁢ ⁢  I ( P / 2 ) - 7 ⁢ N ^ 2  ⁢ ⁢ is ⁢ ⁢ not ⁢ ⁢ < ⁢ 1 - N ^ 2 + ⌊ N ^ 2 ⌋ .