With the explosive growth and need for high-speed wireless communications, more and more energy is consumed to support the required quality of service. Therefore, energy efficient or green communication has become a v...With the explosive growth and need for high-speed wireless communications, more and more energy is consumed to support the required quality of service. Therefore, energy efficient or green communication has become a very hot topic under the ground of limited energy resource and environmentally friendly transmission schemes. MIMO technique is capable of reducing the transmission power thanks to its diversity and multiplexing gain. Moreover, antenna selection(AS) is an alternative to extract many of the benefits in MIMO systems with a reduced cost of complexity and power. Although many works including several survey papers have investigated AS in MIMO systems, the goal of these works is only the capacity maximization or error rate minimization, which fails to guarantee the optimality of the energy efficiency in MIMO systems. In this paper, we overview the state of the art in the AS schemes in energy efficient MIMO systems, the goal of which is to optimize the energy efficiency of the whole system. Specifically, we introduce energy efficient AS in point-to-point MIMO, cooperative MIMO, multiuser MIMO and largescale MIMO systems, respectively. Several challenging and practical issues in this area are also addressed.展开更多
Wireless sensor network(WSN) is a typical kind of low-power and lossy network,in where ARQ(Automatic Repeat reQuest)schemes are often used to improve packets reliability.However,the ARQ related packets may incur signi...Wireless sensor network(WSN) is a typical kind of low-power and lossy network,in where ARQ(Automatic Repeat reQuest)schemes are often used to improve packets reliability.However,the ARQ related packets may incur significant load and consume more energy.This paper proposes a novel energy efficient ARQ protocol called ARQ+,which uses the nearest-first scheme and NAK aggregation scheme to reduce the amount and transmission hops of the ARQ related packets.Consequently,the energy consumption is significantly decreased.Theoretical analyses of ARQ+ on energy consumption,packet arrive ratio and latency are provided.Performance improvement of ARQ+ is validated by extensive simulations.They both show that ARQ+ has satisfactory energy efficiency,good packets arriving ratio and reasonable average packet delay comparing to traditional ARQ schemes.展开更多
Building energy conservation is the basis for carbon emission reduction, through elaborating the relationship between low carbon and energy efficient building. It points out that the construction of energy-saving emis...Building energy conservation is the basis for carbon emission reduction, through elaborating the relationship between low carbon and energy efficient building. It points out that the construction of energy-saving emission reduction is an effective means to solve the problems of high energy consumption of the building, and it is also an important measure for China＇s carbon emission reduction. According to the climate characteristics in hot summer and cold winter area, low carbon technology suitable for the construction of energy-efficient hot summer and cold winter area is proposed which is based on the analysis of the current main building energy-saving technical measures.展开更多
基金supported by NSFC under grant No. 61322111 and No. 61401249the National Basic Research Program of China (973 Program) No. 2013CB336600+1 种基金Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP) under Grant No. 20130002120001Chuanxin Funding, and Beijing nova program No.Z121101002512051
文摘With the explosive growth and need for high-speed wireless communications, more and more energy is consumed to support the required quality of service. Therefore, energy efficient or green communication has become a very hot topic under the ground of limited energy resource and environmentally friendly transmission schemes. MIMO technique is capable of reducing the transmission power thanks to its diversity and multiplexing gain. Moreover, antenna selection(AS) is an alternative to extract many of the benefits in MIMO systems with a reduced cost of complexity and power. Although many works including several survey papers have investigated AS in MIMO systems, the goal of these works is only the capacity maximization or error rate minimization, which fails to guarantee the optimality of the energy efficiency in MIMO systems. In this paper, we overview the state of the art in the AS schemes in energy efficient MIMO systems, the goal of which is to optimize the energy efficiency of the whole system. Specifically, we introduce energy efficient AS in point-to-point MIMO, cooperative MIMO, multiuser MIMO and largescale MIMO systems, respectively. Several challenging and practical issues in this area are also addressed.
基金partly supported by the National Key Technology Research and Development Program of China under Grant No.2011BAK12B02the National Natural Science Foundation of China under Grant No.61104042+2 种基金the National S&T Major Project of China under Grant No.2010ZX03005-003the Program for New Century Excellent Talents in University(NCET-10-0294),Chinathe National Natural Science Foundation of China under Grant No.60832007
文摘Wireless sensor network(WSN) is a typical kind of low-power and lossy network,in where ARQ(Automatic Repeat reQuest)schemes are often used to improve packets reliability.However,the ARQ related packets may incur significant load and consume more energy.This paper proposes a novel energy efficient ARQ protocol called ARQ+,which uses the nearest-first scheme and NAK aggregation scheme to reduce the amount and transmission hops of the ARQ related packets.Consequently,the energy consumption is significantly decreased.Theoretical analyses of ARQ+ on energy consumption,packet arrive ratio and latency are provided.Performance improvement of ARQ+ is validated by extensive simulations.They both show that ARQ+ has satisfactory energy efficiency,good packets arriving ratio and reasonable average packet delay comparing to traditional ARQ schemes.
文摘Building energy conservation is the basis for carbon emission reduction, through elaborating the relationship between low carbon and energy efficient building. It points out that the construction of energy-saving emission reduction is an effective means to solve the problems of high energy consumption of the building, and it is also an important measure for China＇s carbon emission reduction. According to the climate characteristics in hot summer and cold winter area, low carbon technology suitable for the construction of energy-efficient hot summer and cold winter area is proposed which is based on the analysis of the current main building energy-saving technical measures.
