Abstract—Space-time block codes (STBCs) from Orthogonal designs have attracted attention due to their fast maximum likelihood decoding and full diversity, but the maximum symbol transmission rate for complex signals is only ¾ for four transmit antennas so quasi orthogonal STBC was proposed, in this paper the structure and characteristics of some new type of a Quasi-orthogonal space time block codes (QOSTBC)is analyzed, The error performance for these codes for four transmitted antennas over uncorrelated and spatially correlated MIMO channels is investigated. A maximum likelihood (ML) decoding algorithm for the suggested code is also provided.

Index Terms—Diversity, space time codes, MIMO systems, quasi-orthogonal codes.

The authors are with the Electrical Engineering Department, Faculty of Engineering, Alexandria University, Egypt (email:eman_hamdan@yahoo.com).

Cite: Eman Hamdan, Onsy Abdel Alim, and Noha Korany, "Quasi Orthogonal Space Time Block Codes Using Various Sub-Block Matrices," International Journal of Computer and Communication Engineering vol. 1, no. 3, pp. 210-213 , 2012.