Data Detection in Single User Massive MIMO Using Re-Transmissions

Background:Single user Massive Multiple Input Multiple Output (MIMO) can be used to increase the spectral efficiency since the data is transmitted simultaneously from a large number of antennas located at both the base station and mobile. It is feasible to have a large number of antennas in the mobile, in the millimeter wave frequencies. However, the major drawback of single user massive MIMO is the high complexity of data recovery at the receiver.Methods:In this work, we propose a low complexity method of data detection with the help of re-transmissions. A turbo code is used to improve the Bit-Error-Rate (BER).Results and Conclusion:Simulation results indicate a significant improvement in BER with just two re-transmissions as compared to the single transmission case. We also show that the minimum average SNR per bit required for error-free propagation over a massive MIMO channel with re-transmissions is identical to that of the Additive White Gaussian Noise (AWGN) channel, which is equal to -1.6 dB.

A Fast Algorithm for the Demosaicing Problem Concerning the Bayer Pattern

Introduction: In this paper, we deal with the demosaicing problem when the Bayer pattern is used. We propose a fast heuristic algorithm, consisting of three parts. Methods: In the first one, we initialize the green channel by means of an edge-directed and weighted average technique. In the second part, the red and blue channels are updated, thanks to an equality constraint on the second derivatives. The third part consists of a constant-hue-based interpolation. Results: We show experimentally how the proposed algorithm gives in mean better reconstructions than more computationally expensive algorithms.

Side-Informed Image Watermarking Scheme Based on Dither Modulation in the Frequency Domain

Digital communication and media sharing have extensively increased in the last couple of years. Research is focused on protecting digital media through copyright protection. The digital media is secured by watermarking. We have developed an image watermarking technique in the frequency domain to hide secure information in the Discrete Cosine Transform (DCT) coefficients of the carrier image. DCT coefficients are modulated by Dither Modulation (DM). We have increased the modulation step to be able to entirely recover the embedded data (watermark) and increase the robustness of our proposed algorithm to affine transforms and geometrical attacks. Our algorithm showed lower complexity and robustness against different attacks.