495 research outputs found

    A simple and optimum geometric decoding algorithm for MIMO systems

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    Geometric decoding (GD) is a newly proposed decoding technique for multiple-input multiple-output (MIMO) transmission over the fading channels. With a complete search on all symbol vectors in the lattice structure, GD requires about the same decoding complexity to achieve the same optimum block-error rates (BLERs) as that of ML decoding. In this paper, we propose a simple implementation of GD for optimum decoding of MIMO transmission. The GD decoder uses the channel matrix to construct a hyper paraboloid and the zero forcing solution to obtain a hyper ellipsoid projected from the hyper paraboloid. It then restricts the search among the symbol vectors within the hyper ellipsoid. Computer simulation studies on 2x2, 3x3 and 4x 4 MIMO systems transmitting 8P AM and 16QAM show that the proposed GD algorithm can achieve the same BLERs as those of the ML decoders, yet having complexity reduction of more than 90%. © 2009 IEEE.published_or_final_versionThe 4th International Symposium on Wireless and Pervasive Computing (ISWPC 2009), Melbourne, Australia, 11-13 February 2009. In Proceedings of the 4th ISWPC, 2009, p. 1-

    An optimum geometric decoder for MIMO systems

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    In this paper, we propose a simple implementation of an optimum Geometric decoder (GD) for use in MIMO systems. The decoder uses the channel matrix to construct a hyper paraboloid and then restricts the symbol vectors to be searched to a hyper ellipsoid projected from the hyper paraboloid. Computer simulation results on 4×4 different MIMO systems transmitting 16QAM and 64QAM show that the proposed GD can achieve the same bit-error-rate (BER) performances as those of the Maximum Likelihood (ML) decoder, yet having much less complexity.published_or_final_versionThe 5th IEEE GCC Conference & Exhibition, Kuwait City, Kuwait, 17-19 March 2009. In Proceedings of the IEEE GCC Conference & Exhibition, 2009, p. 1-

    A fast geometric decoding algorithm for MIMO systems

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    One of the practical challenges of Wireless communications over Multiple-input Multiple-output (MIMO) channels is to reduce the complexity of the decoding algorithm without sacrifice in performance degradation. Geometric decoding (GD) is an emerging technique which can offer substantially lower complexity while maintaining about the same error rate as that of Maximum likelihood (ML) decoding. In this paper we propose a fast GD algorithm which uses a hyper ellipsoid to reduce the searching region. Simulation results on different MIMO systems transmitting 64QAM show that the proposed GD algorithm can achieve about the same error-rate performance as an ML decoder, yet having less than 5% of the decoding complexity of an ML decoder.published_or_final_versionThe 11th International Conference on Advanced Communication Technology (ICACT 2009), Phoenix Park, Korea, 15-18 February 2009. Proceedings of the ICACT, 2009, v. 3, p. 2108-211

    Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

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    The decay channel ψπ+πJ/ψ(J/ψγppˉ)\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) is studied using a sample of 1.06×1081.06\times 10^8 ψ\psi^\prime events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the ppˉp\bar{p} invariant mass spectrum. The enhancement can be fit with an SS-wave Breit-Wigner resonance function with a resulting peak mass of M=186113+6(stat)26+7(syst)MeV/c2M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2 and a narrow width that is Γ<38MeV/c2\Gamma<38 {\rm MeV/}c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics

    Human Angiostrongyliasis Outbreak in Dali, China

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    Angiostrongyliasis, caused by the rat lungworm Angiostrongylus cantonensis, is a potentially fatal food-borne disease. It is endemic in parts of Southeast Asia, the Pacific Islands, Australia, and the Caribbean. Outbreaks have become increasingly common in China due to the spread of efficient intermediate host snails, most notably Pomacea canaliculata. However, infections are difficult to detect since the disease has a rather long incubation period and few diagnostic clinical symptoms. Reliable diagnostic tests are not widely available. The described angiostrongyliasis epidemic in Dali, China lasted for eight months. Only 11 of a total of 33 suspected patients were clinically confirmed based on a set of diagnostic criteria. Our results demonstrate that the rapid and correct diagnosis of the index patient is crucial to adequately respond to an epidemic, and a set of standardized diagnostic procedures is needed to guide clinicians. Integrated control and management measures including health education, clinical guidelines and a hospital-based surveillance system, should be implemented in areas where snails are a popular food item

    Independent measure of the neutrino mixing angle θ13 via neutron capture on hydrogen at Daya Bay

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