The energy efficiency and packet delay tradeoffs in long term evolution-advanced(LTE-A) systems are investigated.Analytical expressions are derived to explain the relation of energy efficiency to mean packet delay,arr...The energy efficiency and packet delay tradeoffs in long term evolution-advanced(LTE-A) systems are investigated.Analytical expressions are derived to explain the relation of energy efficiency to mean packet delay,arrival rate and component carrier(CC) configurations,from the theoretical respective which reveals that the energy efficiency of multiple CC systems is closely related to the frequency of CCs and the number of active CCs.Based on the theoretical analysis,a CC adjusting scheme for LTE-A systems is proposed to maximize energy efficiency subject to delay constraint by dynamically altering the on/off state of CCs according to traffic variations.Numerical and simulation results show that for CCs in different frequency bands with equal transmit power,the proposed scheme could significantly improve the energy efficiency of users in all aggregation levels within the constraint of mean packet delay.展开更多
The long term evolution advanced （LTE-advanced） standards target at high system performance comparable or superior to the requirements of the International mobile telecommunications advanced （IMT-advanced）. In ord...The long term evolution advanced （LTE-advanced） standards target at high system performance comparable or superior to the requirements of the International mobile telecommunications advanced （IMT-advanced）. In order to support backward compatibility with LTE, most of the key technologies have been retained in LTE-advanced, one of which is the discontinuous reception mechanism （DRX）. LTE-advanced adopts carrier aggregation technology to extend the system bandwidth, which requires the LTE DRX applied in single-transceiver scenario to be adapted to multi-transceiver scenario with multiple component carriers. Apparently, carrier aggregation will influence the performance of DRX severely, so it＇s worth studying the impact brought by the coexistence ofLTE DRX and carrier aggregation on the system performance, e.g., the system delay. In this paper, first an overview of DRX in carrier aggregation scenario is given. Then it is modeled as a Markov process based on the queuing theory. Simulation results show that the independent component carrier configuration with a uniform Inactivity Timer achieves a superior service delay performance compared with other reference schemes.展开更多
基金Supported by the National High Technology Research and Development Program of China(No.2011AA01A109)the National Natural Science Foundation of China(No.61002017,61072076.)the Department of Science and Technology Commission of Shanghai Base Project(No.11DZ2290100)
文摘The energy efficiency and packet delay tradeoffs in long term evolution-advanced(LTE-A) systems are investigated.Analytical expressions are derived to explain the relation of energy efficiency to mean packet delay,arrival rate and component carrier(CC) configurations,from the theoretical respective which reveals that the energy efficiency of multiple CC systems is closely related to the frequency of CCs and the number of active CCs.Based on the theoretical analysis,a CC adjusting scheme for LTE-A systems is proposed to maximize energy efficiency subject to delay constraint by dynamically altering the on/off state of CCs according to traffic variations.Numerical and simulation results show that for CCs in different frequency bands with equal transmit power,the proposed scheme could significantly improve the energy efficiency of users in all aggregation levels within the constraint of mean packet delay.
基金supported by Major national S&T project(2009ZX03003-003-01)the National Natural Science Foundation of China (60971125, 60832009)
文摘The long term evolution advanced （LTE-advanced） standards target at high system performance comparable or superior to the requirements of the International mobile telecommunications advanced （IMT-advanced）. In order to support backward compatibility with LTE, most of the key technologies have been retained in LTE-advanced, one of which is the discontinuous reception mechanism （DRX）. LTE-advanced adopts carrier aggregation technology to extend the system bandwidth, which requires the LTE DRX applied in single-transceiver scenario to be adapted to multi-transceiver scenario with multiple component carriers. Apparently, carrier aggregation will influence the performance of DRX severely, so it＇s worth studying the impact brought by the coexistence ofLTE DRX and carrier aggregation on the system performance, e.g., the system delay. In this paper, first an overview of DRX in carrier aggregation scenario is given. Then it is modeled as a Markov process based on the queuing theory. Simulation results show that the independent component carrier configuration with a uniform Inactivity Timer achieves a superior service delay performance compared with other reference schemes.
