窄带蜂窝物联网(NB-IoT)技术发展迅猛,与原有的无线通信协议相比,NB-IoT的频谱带宽仅有180 k Hz,因此,如何更有效地使用资源或频谱(即资源分配和调度)成为NB-IoT技术的关键问题。针对该问题,对NB-IoT上行链路资源调度的相关因素,其中包...窄带蜂窝物联网(NB-IoT)技术发展迅猛,与原有的无线通信协议相比,NB-IoT的频谱带宽仅有180 k Hz,因此,如何更有效地使用资源或频谱(即资源分配和调度)成为NB-IoT技术的关键问题。针对该问题,对NB-IoT上行链路资源调度的相关因素,其中包括资源分配、功率控制以及上行传输间隙进行了分析,并提供不同选择方案以选择出最优的方案;另外,针对调制与编码方案和重复传输次数的选择进行了重点分析,提出基于不同的覆盖等级联合功率余量报告的贪婪-稳定选择调制与编码策略以初步选择调制与编码级别,在选择重复传输次数时引入了一个补偿因子以衡量重传次数的大小以及对调制与编码等级更新;最后,对所提出方案进行了仿真分析。仿真结果表明,所提方案与直接传输方法相比,平均可节省超过56%的活动时间和46%的资源消耗。展开更多
The problem of transmission power control in a rate-aware way is investigated to improve the throughput of wireless ad hoc network. The behavior of basic IEEE 802.11 DCF is approximated by the p-persistent CSMA throug...The problem of transmission power control in a rate-aware way is investigated to improve the throughput of wireless ad hoc network. The behavior of basic IEEE 802.11 DCF is approximated by the p-persistent CSMA through a Markov chain model. The throughput model takes hidden terminals, muhi-hop flow and concurrent interference into account. Numerical results show that the optimal transmission power derived from this model could balance the tradeoff between spatial reuse and data rate and hence yield maximum throughput.展开更多
It has been demonstrated that either Channel Allocation （CA） or Relay Selection （RS） can improve the performance in relaying networks separately. However, there is little work concerning their combination in multi...It has been demonstrated that either Channel Allocation （CA） or Relay Selection （RS） can improve the performance in relaying networks separately. However, there is little work concerning their combination in multi-cell uplink scenarios. In this paper, we investigate the issue which considers the CA and RS to optimize the system transmission rate in an uplink scenario, while maintaining the resource distribution fairness among users. This is first formulated as an optimization problem for a linear cellular system, where the same frequency channels can be reused in different cells. Based on the link and co-channel interference conditions, two low-complexity CA and RS schemes are then proposed with different decomposition se quences. Finally, numerical results are con ducted to verify the effectiveness of the pro posed CA and RS methods. Simulations re suits show that the proposed methods can yield significant improvements in system per formance in terms of average sum rate.展开更多
Two methods of calculating the parameters and characterizing the degree of pulse electrical disturbances influence on digital devices functioning, both analytical and numerical, are considered here. The analytical met...Two methods of calculating the parameters and characterizing the degree of pulse electrical disturbances influence on digital devices functioning, both analytical and numerical, are considered here. The analytical method permits one to assess the error occurrence probability in transmitting the data packets considering the dependence on the signal pulses energies-to-pulse disturbances energies ratio and the disturbances repetition frequency-to-data transmission rate ratio and also the dependence on the bits quantity in the packet. The numerical method allows one to assess the specific effect of the repetitive pulse disturbance influence on the digital devices functioning （the number of errors in transmitted data packets, transmission rate, etc.） depending on such factors as the repetition frequency, the disturbance waveform and duration, the mode of data coding, etc..展开更多
文摘窄带蜂窝物联网(NB-IoT)技术发展迅猛,与原有的无线通信协议相比,NB-IoT的频谱带宽仅有180 k Hz,因此,如何更有效地使用资源或频谱(即资源分配和调度)成为NB-IoT技术的关键问题。针对该问题,对NB-IoT上行链路资源调度的相关因素,其中包括资源分配、功率控制以及上行传输间隙进行了分析,并提供不同选择方案以选择出最优的方案;另外,针对调制与编码方案和重复传输次数的选择进行了重点分析,提出基于不同的覆盖等级联合功率余量报告的贪婪-稳定选择调制与编码策略以初步选择调制与编码级别,在选择重复传输次数时引入了一个补偿因子以衡量重传次数的大小以及对调制与编码等级更新;最后,对所提出方案进行了仿真分析。仿真结果表明,所提方案与直接传输方法相比,平均可节省超过56%的活动时间和46%的资源消耗。
基金the National High Technology Research and Development Programme of China(No.2004AA104280.2006AA01Z172)
文摘The problem of transmission power control in a rate-aware way is investigated to improve the throughput of wireless ad hoc network. The behavior of basic IEEE 802.11 DCF is approximated by the p-persistent CSMA through a Markov chain model. The throughput model takes hidden terminals, muhi-hop flow and concurrent interference into account. Numerical results show that the optimal transmission power derived from this model could balance the tradeoff between spatial reuse and data rate and hence yield maximum throughput.
基金supported by the Key Project of State Key Laboratory of Rail Traffic and Control under Grant No.RCS2012ZZ004the Fundamental Research Funds for the Central Universities under Grant No. 2013YJS025
文摘It has been demonstrated that either Channel Allocation （CA） or Relay Selection （RS） can improve the performance in relaying networks separately. However, there is little work concerning their combination in multi-cell uplink scenarios. In this paper, we investigate the issue which considers the CA and RS to optimize the system transmission rate in an uplink scenario, while maintaining the resource distribution fairness among users. This is first formulated as an optimization problem for a linear cellular system, where the same frequency channels can be reused in different cells. Based on the link and co-channel interference conditions, two low-complexity CA and RS schemes are then proposed with different decomposition se quences. Finally, numerical results are con ducted to verify the effectiveness of the pro posed CA and RS methods. Simulations re suits show that the proposed methods can yield significant improvements in system per formance in terms of average sum rate.
文摘Two methods of calculating the parameters and characterizing the degree of pulse electrical disturbances influence on digital devices functioning, both analytical and numerical, are considered here. The analytical method permits one to assess the error occurrence probability in transmitting the data packets considering the dependence on the signal pulses energies-to-pulse disturbances energies ratio and the disturbances repetition frequency-to-data transmission rate ratio and also the dependence on the bits quantity in the packet. The numerical method allows one to assess the specific effect of the repetitive pulse disturbance influence on the digital devices functioning （the number of errors in transmitted data packets, transmission rate, etc.） depending on such factors as the repetition frequency, the disturbance waveform and duration, the mode of data coding, etc..
