Optimal Transmission with Imperfect Channel State Information at theTransmit Antenna Array

摘要: We study the optimal transmission strategy of a multiple-input single-output wireless communication link. The receiver has perfect channel state information while transmitter only long-term in terms covariance matrix. It was recently shown that eigenvectors transmit matrix correspond with eigenvalues However, are difficult to compute. properties these capacity achieving eigenvalues, and present necessary sufficient condition for Furthermore, we develop when transmitting all directions. compare gain an diversity system which works beamforming, derive upper bound. answer main questions regarding design using developed results. Additionally, show way multiplexing can be computed case is given. compute maximum number required parallel data streams, define function order obtain measure available gain. small considering additional complexity at receiver. illustrate results by numerical simulations.