Patent ID: 8102949

Claim:
A non-transitory computer readable medium comprising: instructions for causing a wireless communications user terminal (UT) to generate a bit log likelihood ratio (LLR) values for two-layered quadrature phase-shift keying (QPSK) turbo decoding by: receiving a two-layered QPSK signal with in phase (I) and quadrature (Q) components per symbol and with an energy ratio selected from a group comprising k 1 2 and k 2 2 ; selecting a mismatched energy ratio (k 2 ) between k 1 2 and k 2 2 ; and generating the bit LLR values for the two-layered QPSK turbo decoding, using the mismatched k 2 energy ratio and including determining the bit LLR values for four bits (b 3 , b 2 , b 1 , and b 0 ), wherein determining the bit LLR values includes determining the bit LLR values for each b 0 and b 2 bit as follows: L ⁢ ⁢ L ⁢ ⁢ R 2 , 0 = 1 N 0 × 2 1 + k 2 × (  J  - k · C * · C ) ; where J is v for b 0 , and w for b 2 ; v =√{square root over (2(1+ k 2 ))}Re[ C*r]; w =√{square root over (2(1+ k 2 ))}Im[ C*r]; r is the complex received signal; C is the complex channel estimate; and, C* is the complex conjugate of C.