Spatial multiplexing systems can provide significant capacity improvement but are sensitive to channel correlation. Antenna selection is a low-cost low-complexity ahemative to resolve these problems. This paper propos...Spatial multiplexing systems can provide significant capacity improvement but are sensitive to channel correlation. Antenna selection is a low-cost low-complexity ahemative to resolve these problems. This paper proposes a new transmit antenna selection algorithm for the spatial multiplexing systems with the Vertical-Bell Labs Layered Space-Time （V-BLAST） nonlinear receiver in correlated channel. The proposed scheme separates the optimization into two parts： it first chooses the optimal number of substreams in terms of the singular values of the channel matrix, then adapts the mapping of substreams to antennas according to the post-detection signal-to-noise ratio （SNR）. Simulation results illustrate that the proposed two-step selection criterion can provide greater selection gain than the existing singnlar value based selection criterion as SNR and scattering angle increases. The proposed criterion outperforms the existing one by 0.3 dB at a vector symbol error rate of 10^- 3 and scattering angle of 20 degree.展开更多
The paper presents a new method to synthesize β-Sialon bonded corundum brick (β-SBCB) from Al-Si alloy directly and easily under 1430℃ , the volume expansion of reaction between Al powder and Nitrogen can help to e...The paper presents a new method to synthesize β-Sialon bonded corundum brick (β-SBCB) from Al-Si alloy directly and easily under 1430℃ , the volume expansion of reaction between Al powder and Nitrogen can help to establish the fast diffusion channel in Al-Si alloy; the suitable crystal seed of Si3N4 is helpful to the fast synthesis of β-Sialon.展开更多
基金Supported by the National Natural Science Foundation of China （ No. 60372055 ） and the High Technology Resarch and Development Programnse of China （No. 2003AA123320）.
文摘Spatial multiplexing systems can provide significant capacity improvement but are sensitive to channel correlation. Antenna selection is a low-cost low-complexity ahemative to resolve these problems. This paper proposes a new transmit antenna selection algorithm for the spatial multiplexing systems with the Vertical-Bell Labs Layered Space-Time （V-BLAST） nonlinear receiver in correlated channel. The proposed scheme separates the optimization into two parts： it first chooses the optimal number of substreams in terms of the singular values of the channel matrix, then adapts the mapping of substreams to antennas according to the post-detection signal-to-noise ratio （SNR）. Simulation results illustrate that the proposed two-step selection criterion can provide greater selection gain than the existing singnlar value based selection criterion as SNR and scattering angle increases. The proposed criterion outperforms the existing one by 0.3 dB at a vector symbol error rate of 10^- 3 and scattering angle of 20 degree.
文摘The paper presents a new method to synthesize β-Sialon bonded corundum brick (β-SBCB) from Al-Si alloy directly and easily under 1430℃ , the volume expansion of reaction between Al powder and Nitrogen can help to establish the fast diffusion channel in Al-Si alloy; the suitable crystal seed of Si3N4 is helpful to the fast synthesis of β-Sialon.
