This study presents a low-complexity and robust H-infinity channel estimator for multiple-inputmultiple-output (MIMO) orthogonalfrequencydivisionmultiplexing (OFDM) systems. The H-infinity estimator, which has nev...
详细信息
This study presents a low-complexity and robust H-infinity channel estimator for multiple-inputmultiple-output (MIMO) orthogonalfrequencydivisionmultiplexing (OFDM) systems. The H-infinity estimator, which has never been devoted to MIMO-OFDM systems, could be implemented by applying a multiple-order auto-regression (AR) model. However, it may increase the design complexity of receivers and lead to poor real-time property when this model is used for MIMO-OFDM systems, which makes the authors abandon AR model. In order to reduce the number of matrices manipulations because of the each received OFDM symbols from different transmit antennas, the iterative space-alternating generalised expectation-maximisation (SAGE) algorithm is adopted. Furthermore, to deal with the effect of non-Gaussian noise (NGN) channels, because of various natural or man-made impulsive sources, an equivalent signal model (ESM) is introduced to alleviate the effect of this issue and enhance the robust of SAGE-based H-infinity estimator. Simulation results show that H-infinity estimator has almost the same bit error rate performance as optimal maximum a posteriori estimator. The performance gain afforded by using ESM can be substantial when compared with using the traditional signal model, which dramatically enhance the robustness of SAGE-based H-infinity estimator against NGN channels.
In this study, two relay selection methods in the half-duplex decode-and-forward relaying for cooperative multiple-input multiple-output-orthogonal frequency division multiplexing (MIMO-OFDM) systems have been introdu...
详细信息
In this study, two relay selection methods in the half-duplex decode-and-forward relaying for cooperative multiple-input multiple-output-orthogonal frequency division multiplexing (MIMO-OFDM) systems have been introduced. The relay selections are implemented using the symbol-based and subcarrier-based methods. By considering different number of antennas for source, each relay, and destination, the authors have derived closed-form outage expressions for these proposed methods. The MIMO channel model for each subcarrier, between source-relay and relay-destination is considered as a MIMO Rician fading channel with independent but not necessary identically distributed. Moreover, the outage expressions for MIMO independent and identically distributed Rician and Rayleigh fading channels are derived as special cases. Furthermore, the correlation among the OFDM subchannels is analysed. In addition, the implementation issues of both relay selection methods are also investigated. Monte Carlo simulations are performed to validate the outage analysis where the excellent agreement between the analytical and simulation results is observed.
multiple-inputmultiple-output - orthogonalfrequencydivisionmultiplexing (MIMO-OFDM) is adopted to vehicular networks to increase the capacity, reliability and speed. In this paper, iterative demodulation and decod...
详细信息
ISBN:
(纸本)9781479960798
multiple-inputmultiple-output - orthogonalfrequencydivisionmultiplexing (MIMO-OFDM) is adopted to vehicular networks to increase the capacity, reliability and speed. In this paper, iterative demodulation and decoding algorithms are studied to approach the capacity of MIMO-OFDM vehicular networks. By analysing the drawbacks of the Gaussian approximation on the interference cancellation, Non-Gaussian approximation is proposed to enhance the performance of interference cancellation based detectors with large constellations. Simulation results demonstrate that the proposed non-Gaussian algorithm can achieve a significant performance gain over existing ones with high order constellations.
暂无评论