tailieunhanh - báo cáo hóa học:" Research Article Robust THP Transceiver Designs for Multiuser MIMO Downlink with Imperfect CSIT"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Robust THP Transceiver Designs for Multiuser MIMO Downlink with Imperfect CSIT | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2009 Article ID 473930 13 pages doi 2009 473930 Research Article Robust THP Transceiver Designs for Multiuser MIMO Downlink with Imperfect CSIT P. Ubaidulla and A. Chockalingam Department of Electrical Communication Engineering Indian Institute of Science Bangalore 560012 India Correspondence should be addressed to A. Chockalingam achockal@ Received 20 December 2008 Revised 26 April 2009 Accepted 17 July 2009 Recommended by Christoph Mecklenbrauker We present robust joint nonlinear transceiver designs for multiuser multiple-input multiple-output MIMO downlink in the presence of imperfections in the channel state information at the transmitter CSIT . The base station BS is equipped with multiple transmit antennas and each user terminal is equipped with one or more receive antennas. The BS employs Tomlinson-Harashima precoding THP for interuser interference precancellation at the transmitter. We consider robust transceiver designs that jointly optimize the transmit THP filters and receive filter for two models of CSIT errors. The first model is a stochastic error SE model where the CSIT error is Gaussian-distributed. This model is applicable when the CSIT error is dominated by channel estimation error. In this case the proposed robust transceiver design seeks to minimize a stochastic function of the sum mean square error SMSE under a constraint on the total BS transmit power. We propose an iterative algorithm to solve this problem. The other model we consider is a norm-bounded error NBE model where the CSIT error can be specified by an uncertainty set. This model is applicable when the CSIT error is dominated by quantization errors. In this case we consider a worst-case design. For this model we consider robust i minimum SMSE ii MSE-constrained and iii MSE-balancing transceiver designs. We propose iterative algorithms to solve these problems wherein each .