Radio resources must be wisely managed, in wireless communication systems, when implementing different multiple access techniques. This perspective is pivotal since the variations in propagation channel are very fast ...Radio resources must be wisely managed, in wireless communication systems, when implementing different multiple access techniques. This perspective is pivotal since the variations in propagation channel are very fast and the system is highly complex due to random and unpredictable movement of mobile users continuously. The complexity in the cellular system periodically contributes to different interference levels, high or low, resulting in the degradation of the system capacity. Transmitter power control is an efficient technique to mitigate the effect of interference under fading conditions, combat the Near-Far problem and conserve the battery life. Several remedial measures—like space diversity, frequency diversity, route diversity, increase in antenna height, antenna tilting, etc.—have been tried by many operators to overcome the debilitating effect of multipath fading in fixed line-of-sight microwave and mobile communication links. Among these remedial measures, diversity techniques have been extensively studied in terms of improvement factor, whereas the concept of antenna tilting is relatively less explored compared with other remedial measures. In this study, the effect of antenna tilting on fixed and mobile communication links is investigated to find out the optimum tilting angles in terms of design parameters, as well as on quality of service (QoS). The paper established that a deviation of more than 1.5o in antenna elevation angle would impact on QoS requirements and seriously affect the quality of signal to be received by the mobile systems.展开更多
AVO分析方法是利用地震反射波振幅与炮检距的关系（Amplitude versus Offset简称AVO）来识别岩性检测油气的一种地震技术。与榆林气田相似，在子洲气田勘探中，运用该技术见到很好效果。子洲气田上古生界二叠系山西组合气砂岩主要属三...AVO分析方法是利用地震反射波振幅与炮检距的关系（Amplitude versus Offset简称AVO）来识别岩性检测油气的一种地震技术。与榆林气田相似，在子洲气田勘探中，运用该技术见到很好效果。子洲气田上古生界二叠系山西组合气砂岩主要属三角洲平原及三角洲前缘分流河道沉积。由于含气砂岩和致密砂岩在波阻抗上差异较小．在常规的岩性反演剖面上，很难区分含气砂岩和致密砂岩。引入AVO处理分析方法，利用不同岩性泊松比差异所形成的AVO特征响应．可以有效区分地震高阻抗层的岩性及含气性，从而减少了地震岩性解释上的陷阱。在开发中。应用高保真的CMP道集资料进行AVO处理分析，是提高天然气开发井预测成功率的一种有效手段。展开更多
文摘Radio resources must be wisely managed, in wireless communication systems, when implementing different multiple access techniques. This perspective is pivotal since the variations in propagation channel are very fast and the system is highly complex due to random and unpredictable movement of mobile users continuously. The complexity in the cellular system periodically contributes to different interference levels, high or low, resulting in the degradation of the system capacity. Transmitter power control is an efficient technique to mitigate the effect of interference under fading conditions, combat the Near-Far problem and conserve the battery life. Several remedial measures—like space diversity, frequency diversity, route diversity, increase in antenna height, antenna tilting, etc.—have been tried by many operators to overcome the debilitating effect of multipath fading in fixed line-of-sight microwave and mobile communication links. Among these remedial measures, diversity techniques have been extensively studied in terms of improvement factor, whereas the concept of antenna tilting is relatively less explored compared with other remedial measures. In this study, the effect of antenna tilting on fixed and mobile communication links is investigated to find out the optimum tilting angles in terms of design parameters, as well as on quality of service (QoS). The paper established that a deviation of more than 1.5o in antenna elevation angle would impact on QoS requirements and seriously affect the quality of signal to be received by the mobile systems.
文摘AVO分析方法是利用地震反射波振幅与炮检距的关系（Amplitude versus Offset简称AVO）来识别岩性检测油气的一种地震技术。与榆林气田相似，在子洲气田勘探中，运用该技术见到很好效果。子洲气田上古生界二叠系山西组合气砂岩主要属三角洲平原及三角洲前缘分流河道沉积。由于含气砂岩和致密砂岩在波阻抗上差异较小．在常规的岩性反演剖面上，很难区分含气砂岩和致密砂岩。引入AVO处理分析方法，利用不同岩性泊松比差异所形成的AVO特征响应．可以有效区分地震高阻抗层的岩性及含气性，从而减少了地震岩性解释上的陷阱。在开发中。应用高保真的CMP道集资料进行AVO处理分析，是提高天然气开发井预测成功率的一种有效手段。
