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A Data-Bearing Approach for Pilot-Aiding in Space-Time Coded MIMO Systems

This paper presents a novel technique for pilot-based channel estimation and data detection by exploiting a null-space property and an orthogonality property of the data bearer and pilot matrices. The data and pilot extraction procedures can be done independently by a simple linear transformation exploiting the null-space property. The maximum-likelihood (ML) receiver employed for data detection and the unconstrained-ML estimator employed for channel estimation can be designed separately by using the orthogonality property. In addition, the linear minimum mean-squared error (LMMSE) channel estimator is also proposed to improve the performance of channel estimation. The simulation results show that, among three data bearer and pilot structures including time-multiplexing (TM)-based, ST-block-code (STBC)-based, and code-multiplexing (CM)-based structures, the CM-based structure shows superior performance over the TM-based and the STBC-based structures in term of the probability of detection error, e.g. BER, for nonquasi-static flat Rayleigh fading channels, while the performances of these three structures are quite close for quasi-static flat Rayleigh fading channels