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The design of the channel estimation method in a multiple-input multiple-output (MIMO) relay system plays a highly crucial role in deciding the overall system performance. For the realistic scenarios specifically, with fast time-varying channel conditions due to highly mobile communicating nodes, the degree of accuracy to which the channel estimates are obtained for MIMO relay systems influences the communication system reliability significantly. However, most of the channel estimation approaches proposed in literature for MIMO relay systems assume that the Doppler offset contributed by highly mobile nodes is already known to the receiver, ignoring the resulting nonlinear system dynamics. Hence, a novel hybrid algorithm is proposed to address the issue of timevarying channel estimation under fast-fading channel condition with Doppler offset influences contributed by high-mobility communicating nodes for a 1way 2-hop MIMO amplify-and-forward relaying system. The problem is first formulated as a nonlinear state-space model, and then an algorithm is developed to estimate the individual source-to-relay and relay-to-destination channels in the presence of the associated dynamic Doppler offset. In the proposed method, a set of superimposed orthogonal pilots is used for aiding in the updation of the channel gains, since Kalman filter-based updation may lead to accumulation of estimation and prediction error. A detailed computational complexity analysis of the proposed hybrid algorithm is presented, which shows that the algorithm has moderate computational complexity with a good performance in fast time-varying channel conditions with high node mobility in a dual-hop MIMO relay system. KEYWORDS channel estimation, Doppler offset, Kalman filter, multiple-input multiple-output (MIMO) relay system, Takagi-Sugeno (T-S) fuzzy model | INTRODUCTIONTo improve the network coverage and power efficiency of a multiple-input multiple-output (MIMO) communication system, 1 relay nodes are added between the source-destination pair. The concept of relaying was first introduced by van der Meulen. 2 Because of the numerous advantages such as reducing the effects of path loss and shadowing 3-6 offered by relays, this study has gained a lot of momentum in research recently. To reap the aforementioned benefits that

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Face Recognition is a term that includes several subproblems. Though face recognition have been a grown up research area, however, there still remain many problems that must be overcome to develop a robust face recognition system that works well under various circumstances such as illumination, pose and expressions variations. Such variations have proven to be one of the biggest problems of face recognition systems. In the proposed thesis work the problem of illumination is discussed. A method based on the combination of Retinex and LOG-DCT technique is applied to suppress the illumination and for better face recognition results. After illumination normalization LBP is used for extracting the features of normalized images, which are further used for face recognition. In the proposed method the experiments on Extended Yale B database show that by using the proposed method better recognition performance and results can be obtained.