To overcome the obstacle of the fascinating relation in predicting animal phenotype value, we have developed a neural network model to detect the complex non-linear relationships between the genotypes and phenotypes a...To overcome the obstacle of the fascinating relation in predicting animal phenotype value, we have developed a neural network model to detect the complex non-linear relationships between the genotypes and phenotypes and the possible interactions that cannot be expressed with equations. In this paper, back-propagation neural network is used to discuss the influences of different allele frequencies on estimating the polygenic phenotype value. To ensure the precision of prediction, normalization was needed to train the prediction model. The results show that back-propagation artificial neural networks can be used to predict the phenotype value and perform very well in allele frequency from 0.2 to 0.8, when the allele frequency is very small （less than 0.2） or big （more than 0.8）; however, the prediction model was not reliable and the predicted value should be carefully tested.展开更多
The multimedia broadcast and multicast services (MBMS) in 3GPP LTE is characterized by multicast broadcast single frequency network (MBSFN) operation. The multicast services are transmitted by single frequency network...The multimedia broadcast and multicast services (MBMS) in 3GPP LTE is characterized by multicast broadcast single frequency network (MBSFN) operation. The multicast services are transmitted by single frequency network (SFN) mode, and the unicast services are delivered with point-to-point (PTP) mode. To minimize the demanded radio resources for multicast services in the LTE, a novel mode switch (MS) between SFN and PTP for multicast services is proposed. MS takes into account PTP mode for multicast services and the switch is based on the handover threshold. To solve the minimization problem, MS adapts the handover threshold with the difference in the demanded radio resources between SFN mode and PTP mode for multicast services. The simulation results show that the proposed MS achieves less demanded radio resources than SFN mode for all the multicast services.展开更多
单频网(Single Frequency Network,SFN)的运行对发射机的同步提出极高的技术要求,任何同步误差都可能对网络性能产生不利影响。首先分析SFN中时间、频率和相位同步误差的定义与分类,其次探讨其对关键性能指标的影响机理,并量化同步误差...单频网(Single Frequency Network,SFN)的运行对发射机的同步提出极高的技术要求,任何同步误差都可能对网络性能产生不利影响。首先分析SFN中时间、频率和相位同步误差的定义与分类,其次探讨其对关键性能指标的影响机理,并量化同步误差对覆盖范围和信道容量的削弱程度,最后针对同步误差的成因提出提高授时源精度、优化参考时钟选型、改进同步跟踪环路设计及多径信号抑制等策略。展开更多
The single frequency network (SFN) can provide a multimedia broadcast multicast service over a large coverage area. However, the application of SFN is still restricted by a large amount of feedback. Therefore, we prop...The single frequency network (SFN) can provide a multimedia broadcast multicast service over a large coverage area. However, the application of SFN is still restricted by a large amount of feedback. Therefore, we propose a multicast resource allocation scheme based on limited feedback to maximize the total rate while guaranteeing the quality of service (QoS) requirement of real-time services. In this scheme, we design a user feedback control algorithm to effectively reduce feedback load. The algorithm determines to which base stations the users should report channel state information. We then formulate a joint subcarrier and power allocation issue and find that it has high complexity. Hence, we first distribute subcarriers under the assumption of equal power and develop a proportional allocation strategy to achieve a tradeoff between fairness and QoS. Next, an iterative water-filling power allocation is proposed to fully utilize the limited power. To further decrease complexity, a power iterative scheme is introduced. Simulation results show that the proposed scheme significantly improves system performance while reducing 68% of the feedback overhead. In addition, the power iterative strategy is suitable in practice due to low complexity.展开更多
多发射机间的同步误差是制约单频网(Single Frequency Network,SFN)信号覆盖质量的关键因素。围绕相位编码技术的特性,分析SFN系统对同步误差的敏感机制,阐述相位编码在多径环境下相较于传统方法的抗干扰优势。通过建立多分量叠加的相...多发射机间的同步误差是制约单频网(Single Frequency Network,SFN)信号覆盖质量的关键因素。围绕相位编码技术的特性,分析SFN系统对同步误差的敏感机制,阐述相位编码在多径环境下相较于传统方法的抗干扰优势。通过建立多分量叠加的相位扰动模型,提出基于双环控制结构的同步误差联合估计方法,设计一种融合变步长机制的自适应均衡补偿算法,验证了相位信息在误差传播抑制中的核心作用。展开更多
基金Supported by the Scientific Research Starting Foundation for Doctors, Henan Institute of Science and Technology of China
文摘To overcome the obstacle of the fascinating relation in predicting animal phenotype value, we have developed a neural network model to detect the complex non-linear relationships between the genotypes and phenotypes and the possible interactions that cannot be expressed with equations. In this paper, back-propagation neural network is used to discuss the influences of different allele frequencies on estimating the polygenic phenotype value. To ensure the precision of prediction, normalization was needed to train the prediction model. The results show that back-propagation artificial neural networks can be used to predict the phenotype value and perform very well in allele frequency from 0.2 to 0.8, when the allele frequency is very small （less than 0.2） or big （more than 0.8）; however, the prediction model was not reliable and the predicted value should be carefully tested.
基金Sponsored by the National Key Technology R&D Program of China ( Grant No. 2010ZX03003-001-01)Fundamental Research Funds for the Central Universities
文摘The multimedia broadcast and multicast services (MBMS) in 3GPP LTE is characterized by multicast broadcast single frequency network (MBSFN) operation. The multicast services are transmitted by single frequency network (SFN) mode, and the unicast services are delivered with point-to-point (PTP) mode. To minimize the demanded radio resources for multicast services in the LTE, a novel mode switch (MS) between SFN and PTP for multicast services is proposed. MS takes into account PTP mode for multicast services and the switch is based on the handover threshold. To solve the minimization problem, MS adapts the handover threshold with the difference in the demanded radio resources between SFN mode and PTP mode for multicast services. The simulation results show that the proposed MS achieves less demanded radio resources than SFN mode for all the multicast services.
文摘单频网(Single Frequency Network,SFN)的运行对发射机的同步提出极高的技术要求,任何同步误差都可能对网络性能产生不利影响。首先分析SFN中时间、频率和相位同步误差的定义与分类,其次探讨其对关键性能指标的影响机理,并量化同步误差对覆盖范围和信道容量的削弱程度,最后针对同步误差的成因提出提高授时源精度、优化参考时钟选型、改进同步跟踪环路设计及多径信号抑制等策略。
基金supported by the National Natural Science Foundation of China (Nos. 60972076 and 61072052)the National Science and Technology Major Project, China (No. 2010ZX03003-004-03)
文摘The single frequency network (SFN) can provide a multimedia broadcast multicast service over a large coverage area. However, the application of SFN is still restricted by a large amount of feedback. Therefore, we propose a multicast resource allocation scheme based on limited feedback to maximize the total rate while guaranteeing the quality of service (QoS) requirement of real-time services. In this scheme, we design a user feedback control algorithm to effectively reduce feedback load. The algorithm determines to which base stations the users should report channel state information. We then formulate a joint subcarrier and power allocation issue and find that it has high complexity. Hence, we first distribute subcarriers under the assumption of equal power and develop a proportional allocation strategy to achieve a tradeoff between fairness and QoS. Next, an iterative water-filling power allocation is proposed to fully utilize the limited power. To further decrease complexity, a power iterative scheme is introduced. Simulation results show that the proposed scheme significantly improves system performance while reducing 68% of the feedback overhead. In addition, the power iterative strategy is suitable in practice due to low complexity.
文摘多发射机间的同步误差是制约单频网(Single Frequency Network,SFN)信号覆盖质量的关键因素。围绕相位编码技术的特性,分析SFN系统对同步误差的敏感机制,阐述相位编码在多径环境下相较于传统方法的抗干扰优势。通过建立多分量叠加的相位扰动模型,提出基于双环控制结构的同步误差联合估计方法,设计一种融合变步长机制的自适应均衡补偿算法,验证了相位信息在误差传播抑制中的核心作用。
