In wireless communications, it is often desirable to merge bit decisions from multiple receivers to improve overall link performance. It is well known that in order to optimally fuse bit decisions from a network of receivers, precise knowledge of receiver bit error rates (BERs) is needed. This information, however, is rarely available in practice. In this work, we present an iterative procedure for blindly estimating receivers BERs to enable near optimal blind fusion of bit decisions in a multi-receiver network. We show that the solution of the estimation problem is a structured eigenvalue task and propose a modified power method procedure to perform it. We prove that the desired solution is a stable point of the algorithm and the algorithm is locally stable. Furthermore, we show via simulations that the technique results in excellent performance in nearly all practical operating scenarios.

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Illegitimate duplication, piracy, circulation and amendment of digitized information are well thought-out infringements aligned with intellectual property rights. Thus digital watermarking came into existence due to the evolving obligation of copyright protection.We have presented a blind digital video watermarking technique based on the Discrete Wavelet transform (DWT), Firefly algorithm and the real Schur Decomposition. The scheme is using optimized firefly algorithm to trace the best DWT blocks with large texture value for inserting watermark and to minimize the error rate. The scheme starts with applying two-level DWT to the video scene. It finds the suitable place to embed watermark using Firefly algorithm and then apply Schur decomposition. Schur uses Singular Value Decomposition to embed the binary watermark bits in the resultant block upper triangular matrix. The proposed technique shows high efficiency since Schur decomposition requires fewer computations compared to other transforms and robustness due to optimized firefly algorithm. It provides better results in terms of imperceptibility and normalized correlation.

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