Signals from the Global Navigation Satellite System （GNSS） scatter over the sea surface resulting in relatively low Signal-to-Noise Ratios （SNR）. A differential coherent algorithm is given here to improve the SNR ...Signals from the Global Navigation Satellite System （GNSS） scatter over the sea surface resulting in relatively low Signal-to-Noise Ratios （SNR）. A differential coherent algorithm is given here to improve the SNR and reduce the performance degradation due to the Squaring-Loss and the navigation-bit effect. The algorithm uses fast navigation-bit correction for Delay-Doppler Maps （DDM） in airborne Global Navigation Satellite Signal Reflectometry （GNSS-R） software receivers. The system model is introduced with an analysis of the statistical properties with simulations to support the theoretical analysis. Field experiments with real airborne receivers then demonstrate the effectiveness of this algorithm. Comparisons with test results show that this algorithm offers a significant SNR gain over conventional algorithms.展开更多
在数字集成电路(Integrated Circuit,IC)设计中,一些流水运行、分级计算的电路,使用全局控制信号(Global Control Signal,GCS)来进行设计是易于实现的一种方法。对于时序紧张的全局控制信号,通过在逻辑设计阶段,降低全局控制信号控制优...在数字集成电路(Integrated Circuit,IC)设计中,一些流水运行、分级计算的电路,使用全局控制信号(Global Control Signal,GCS)来进行设计是易于实现的一种方法。对于时序紧张的全局控制信号,通过在逻辑设计阶段,降低全局控制信号控制优先级;在逻辑综合阶段,加入多周期路径设置的指令,可以将全局控制信号设置为具有多周期路径特性的信号,能够有效地改善时序,降低后期物理设计的布线难度,从而达到设计目的。展开更多
基金supported in part by the National Natural Science Foundation of China(No.61171070)the National High-Tech Research and Development Program (863) of China(No.2011AA120501)
文摘Signals from the Global Navigation Satellite System （GNSS） scatter over the sea surface resulting in relatively low Signal-to-Noise Ratios （SNR）. A differential coherent algorithm is given here to improve the SNR and reduce the performance degradation due to the Squaring-Loss and the navigation-bit effect. The algorithm uses fast navigation-bit correction for Delay-Doppler Maps （DDM） in airborne Global Navigation Satellite Signal Reflectometry （GNSS-R） software receivers. The system model is introduced with an analysis of the statistical properties with simulations to support the theoretical analysis. Field experiments with real airborne receivers then demonstrate the effectiveness of this algorithm. Comparisons with test results show that this algorithm offers a significant SNR gain over conventional algorithms.
文摘在数字集成电路(Integrated Circuit,IC)设计中,一些流水运行、分级计算的电路,使用全局控制信号(Global Control Signal,GCS)来进行设计是易于实现的一种方法。对于时序紧张的全局控制信号,通过在逻辑设计阶段,降低全局控制信号控制优先级;在逻辑综合阶段,加入多周期路径设置的指令,可以将全局控制信号设置为具有多周期路径特性的信号,能够有效地改善时序,降低后期物理设计的布线难度,从而达到设计目的。
