On the Performance of Hybrid Stacked Cyclic Delay Diversity Schemes in MIMO-OFDM

In this paper, a new hybrid stacked cyclic delay diversity (HSCDD) scheme is proposed for the multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems to flexibly maximize the tradeoff between multiplexing and diversity gains. Unlike the existing double space time transmit diversity (DSTTD) and the stacked cyclic delay diversity (SCDD) schemes which are suitable for the integer multiplexing rate, the proposed HSCDD scheme can achieve arbitrary number of multiplexing rate. Another advantage of the proposed HSCDD scheme over the DSTTD and the stacked CDD schemes is the flexibility in selecting the required number of transmit antennas. With this provided flexibility, the HSCDD can optimize the tradeoff between diversity and multiplexing gains to match the user´s requirements.