A Systematic Design of High-Rate Full-Diversity Space-Frequency Codes for Multiuser MIMO-OFDM System

摘要

The authors have proposed a new space-frequency (SF) code for MIMO-OFDM system in their paper. The data streams of all the users are sent simultaneously through all the OFDM subchannels. The proposed SF code can achieve high symbol rate (rate A_t) with full diversity (A_tA_rL) where A_t denotes the number of transmit antenna for each user, A_r denotes number of receive antenna at the receiver and L denotes the number of independent channel taps. The threaded algebraic layering concept is used to construct this SF code which combines the space-frequency layering theory with algebraic component codes. The component code is considered to be an algebraic number theoretic constellation. Each component code is assigned to a "thread" and interleaved over space and frequency. Diophantine approximation theory is then used to make the threads transparent to each other. In addition, another approximation is used so that the users become transparent to each other. Our SF code does not require zero-padding, which always ensures high symbol rate. It is proved through simulation that the proposed coding scheme achieves higher coding and diversity gain over recently proposed space-frequency code.