A Fast Decodable Full-Rate STBC with High Coding Gain for 4x2 MIMO   Systems
  In this work, a new fast-decodable space-time block code (STBC) is proposed. The code is full-rate and full-diversity for 4x2 multiple-input multiple-output (MIMO) transmission. Due to the unique structure of the codeword, the proposed code requires a much lower computational complexity to provide maximum-likelihood (ML) decoding performance. It is shown that the ML decoding complexity is only O(M^{4.5}) when M-ary square QAM constellation is used. Finally, the proposed code has highest minimum determinant among the fast-decodable STBCs known in the literature. Simulation results prove that the proposed code provides the best bit error rate (BER) performance among the state-of-the-art STBCs. 
Ming Liu (IETR), Maryline H\'elard (IETR), Jean-Fran\c{c}ois H\'elard   (IETR), Matthieu Crussi\`ere (IETR)
cs.IT math.IT