An Improved Full Rate Full Diversity QOSTBC with Linear Decoding in MIMO Systems

In this letter, we propose an improved Quasi-orthogonal space-time block code (QOSTBC) with full rate, full diversity, linear decoding and better peak-to-average power ratio (PAPR). Constellation rotation is used to the input symbol vector to ensure full diversity, and then the information symbol vector is interleaved in coordinates and pre-grouped by using a Given rotation matrix. The performance is evaluated by numerical experiments. The PAPR of our proposed QOSTBC is lower than that of CI-QOSTBC in Khan and Rajan (IEEE Trans Inf Theory 52(5):2062–2091, 2006 ). Meanwhile, the Bit-error-rate versus Signal-to-noise-ratio of our proposed QOSTBC is better than those of OSTBC (Tarokh et al. in IEEE Trans Inf Theory 45(5):1456–1467, 1999 ) QOSTBC (Jafarkhani in IEEE Trans Wirel Commun 49(1):1–4, 2001 ), G-QOSTBC (Park et al. in IEEE Commun Lett 12(12):868–870, 2008 ), slightly better that of the CI-QOSTBC, and as same as that of the recently proposed Minimum Decoding Complexity QOSTBCs (MDC-QOSTBC) in Yuen et al.(IEEE Trans Wirel Commun 4(5):2089–2098, 2005 ), Wang and Xia (IEEE Trans Inf Theory 55(3):1104–1130, 2009 ). Compared with MDC-QOSTBC, the proposed QOSTBC has simpler code construct and lower decoding complexity.