Patent ID: 7634703

Claim:
A decoder for a wireless communication device comprising: a calculator for calculating the modulo of a linear approximation of a MAX* function using: ( a ⁡ ( n ) ⁢ mod ⁢ ⁢ F + ( ( b ⁡ ( n ) ⁢ mod ⁢ ⁢ F - a ⁡ ( n ) ⁢ mod ⁢ ⁢ F ) ⁢ mod ⁢ ⁢ F + C ) 2 ) ⁢ mod ⁢ ⁢ F ; and a selector for selecting a MAX* output value from the group a(n)mod F, b(n)mod F, and the calculated modulo based upon a determination as to whether a predetermined threshold value for |a(n)−b(n)| has been met, where a(n) is a first state metric, b(n) is a second state metric, C is the predetermined threshold value and F is a value greater than |a(n)−b(n)|; wherein the decoder is arranged to receive an information bit and to use the selected MAX* output value to decode the received information bit.