Reducing The Detection Complexity By Using 2??2 Multi-Strata Space-Time Codes

The multistrata space-time codes were proposed by Wachsmann et al. to increase the spectral efficiency of orthogonal space-time block codes. However, these codes lack two things: 1) their performance is worse than codes designed using number theory like the Golden code. 2) The advantages of their structure were never exploited in reducing the detection complexity. In this paper, it is shown how the multistrata structure can potentially reduce the detection complexity of the sphere decoder in the uncoded case and a simple means of generating bit log-likelihood ratios in a bit-interleaved coded modulation scenario is presented. Simulation results show that the obtained code has a very small performance penalty compared to the Golden code in the uncoded case and outperforms it in bit-interleaved coded modulation.