The reasons for inducing quadrature error and offset error are analyzed and the expressions of quadrature error and offset error are induced. The open-loop system analysis indicates that, in order to avoid the appeara...The reasons for inducing quadrature error and offset error are analyzed and the expressions of quadrature error and offset error are induced. The open-loop system analysis indicates that, in order to avoid the appearance of harmonic peaks, the frequency difference δf between drive mode and sense mode must be less than 1/（2Qy）. In order to eliminate the effects of the quadrature error and the offset error, as well as the inherent non- linearity in the capacitance-type sensors, a closed-loop feedback control circuit with quadrature correction is designed. The experimental results indicate that the quadrature error and offset error are corrected. By comparing with open-loop detection, the closed-loop feedback control circuit with quadrature correction decreases the non-linearity of the scale factor from 16. 02% to 0. 35 %, widens the maximum rate capability from ± 270 （°）/s to ± 370 （°）/s and increases the stability of zero bias from 155. 2 （°）/h to 60. 6 （°）/h.展开更多
In this paper,a general scheme in digital self-interference cancellation at baseband for zero-IF full-duplex transceivers is presented. We model the self-interference signals specifically with only the nonlinear disto...In this paper,a general scheme in digital self-interference cancellation at baseband for zero-IF full-duplex transceivers is presented. We model the self-interference signals specifically with only the nonlinear distortion signals falling in receiving band considered. A joint estimation algorithm is proposed for compensating the time delay and frequency offset taking into account the IQ amplitude and phase imbalances from mixers. The memory effect and nonlinear distortion are adaptively estimated by the de-correlated normalized least mean square(DNLMS) algorithm. Numerical simulation results demonstrate that the proposed self-interference cancellation scheme can efficiently compensate the self-interference and outperform the existing traditional solutions.展开更多
Through an analysis of China＇s healthcare system and the regulatory model of pharmaceutical pricing, the paper concludes that the prime cause of pharmaceutical pricing inflation is the twodirectional monopoly of publ...Through an analysis of China＇s healthcare system and the regulatory model of pharmaceutical pricing, the paper concludes that the prime cause of pharmaceutical pricing inflation is the twodirectional monopoly of public healthcare institutions on pharmaceutical retailing. The low cost of medical services means that public hospitals can legitimately use the sale of pharmaceuticals to subsidize the provision of services. Moreover, the policy of controlling the rate of return gives public hospitals a further incentive to buy and sell high-cost pharmaceuticals. In addition, the policy of independent pricing together with the laxity of the system for approving new drugs allows the makers of pharmaceutical products to charge higher prices and facilitates public hospitals＇ sale of high-priced drugs. All of these problems result from inappropriate government controls. Therefore, the basic strategy for solving the problem of inflated pharmaceutical prices should be to lessen government controls on healthcare, open up retail sales of prescription medicines, and reform the public healthcare system and medical insurance reimbursement, breaking the monopoly of public hospitals.展开更多
文摘The reasons for inducing quadrature error and offset error are analyzed and the expressions of quadrature error and offset error are induced. The open-loop system analysis indicates that, in order to avoid the appearance of harmonic peaks, the frequency difference δf between drive mode and sense mode must be less than 1/（2Qy）. In order to eliminate the effects of the quadrature error and the offset error, as well as the inherent non- linearity in the capacitance-type sensors, a closed-loop feedback control circuit with quadrature correction is designed. The experimental results indicate that the quadrature error and offset error are corrected. By comparing with open-loop detection, the closed-loop feedback control circuit with quadrature correction decreases the non-linearity of the scale factor from 16. 02% to 0. 35 %, widens the maximum rate capability from ± 270 （°）/s to ± 370 （°）/s and increases the stability of zero bias from 155. 2 （°）/h to 60. 6 （°）/h.
基金supported in part by the National Natural Science Foundation of China(No.61601027)
文摘In this paper,a general scheme in digital self-interference cancellation at baseband for zero-IF full-duplex transceivers is presented. We model the self-interference signals specifically with only the nonlinear distortion signals falling in receiving band considered. A joint estimation algorithm is proposed for compensating the time delay and frequency offset taking into account the IQ amplitude and phase imbalances from mixers. The memory effect and nonlinear distortion are adaptively estimated by the de-correlated normalized least mean square(DNLMS) algorithm. Numerical simulation results demonstrate that the proposed self-interference cancellation scheme can efficiently compensate the self-interference and outperform the existing traditional solutions.
文摘Through an analysis of China＇s healthcare system and the regulatory model of pharmaceutical pricing, the paper concludes that the prime cause of pharmaceutical pricing inflation is the twodirectional monopoly of public healthcare institutions on pharmaceutical retailing. The low cost of medical services means that public hospitals can legitimately use the sale of pharmaceuticals to subsidize the provision of services. Moreover, the policy of controlling the rate of return gives public hospitals a further incentive to buy and sell high-cost pharmaceuticals. In addition, the policy of independent pricing together with the laxity of the system for approving new drugs allows the makers of pharmaceutical products to charge higher prices and facilitates public hospitals＇ sale of high-priced drugs. All of these problems result from inappropriate government controls. Therefore, the basic strategy for solving the problem of inflated pharmaceutical prices should be to lessen government controls on healthcare, open up retail sales of prescription medicines, and reform the public healthcare system and medical insurance reimbursement, breaking the monopoly of public hospitals.
