A Signal Constellation Design for STBC with Spatial and Temporal Modulation

This paper introduces a space-time block code with spatial and temporal modulation (STBC-STM) and proposes a constellation design of STBC-STM based on rotation angle optimization such that the achievable diversity effect is maximized. The STBC-STM transmits information by the degree of freedom offered by multiple transmit antennas (spatial modulation) and multiple time slots (temporal modulation). As a result, spectral efficiency becomes higher than that of the conventional spacetime block code with spatial modulation (STBC-SM) system when the transmitter has three antennas. Similar to conventional STBC-SM, the performance of the proposed STBC-STM depends on the rotation angles among the codebooks. Therefore, in this paper, we attempt to optimize the rotation angle for STBC-STM and compare its performance with the conventional STBC-SM. By theoretical analysis and simulation of the corresponding bit error probability, it is shown that with a suitable selection of a set of rotation angles, the proposed approach can outperform the STBC-SM with optimal angles.