695 research outputs found
Study on Energy Consumption and Coverage of Hierarchical Cooperation of Small Cell Base Stations in Heterogeneous Networks
The demand for communication services in the era of intelligent terminals is
unprecedented and huge. To meet such development, modern wireless
communications must provide higher quality services with higher energy
efficiency in terms of system capacity and quality of service (QoS), which
could be achieved by the high-speed data rate, the wider coverage and the
higher band utilization. In this paper, we propose a way to offload users from
a macro base station(MBS) with a hierarchical distribution of small cell base
stations(SBS). The connection probability is the key indicator of the
implementation of the unload operation. Furthermore, we measure the service
performance of the system by finding the conditional probability-coverage
probability with the certain SNR threshold as the condition, that is, the
probability of obtaining the minimum communication quality when the different
base stations are connected to the user. Then, user-centered total energy
consumption of the system is respectively obtained when the macro base
station(MBS) and the small cell base stations(SBS) serve each of the users. The
simulation results show that the hierarchical SBS cooperation in heterogeneous
networks can provide a higher system total coverage probability for the system
with a lower overall system energy consumption than MBS.Comment: 6 pages, 7 figures, accepted by ICACT201
Scratch generation probability in chemical mechanical polishing (CMP) process
Chemical mechanical polishing (CMP) process is a critical new technology to planarize the wafer surface aided by the combined force of the chemical etching and mechanical polishing. In this process, defectivity due to scratch generation has become more and more important as it influences the wafer product quality, throughput and cost significantly with the technology developments into sub 100 nanometer technology nodes. The overall objective of this research is to investigate the effects of particle agglomeration on scratch generation and predict the scratch generation probability in CMP process. A mechanical model considering smooth wafer surface and varying height pad asperities for CMP process will be selected. The indentation depth is taken as a measurement of the scratch depth. The probability of such indentation depth of the scratch is simulated with evolving pad surface topography and changing slurry particle size distribution. Diffusion Limited Agglomeration (DLA) and Reaction Limited Agglomeration (RLA) model will be developed to describe the slurry particle size distribution evolution. Predictions for scratch generation probability are compared with those two different agglomeration models
End to End Performance Analysis of Relay Cooperative Communication Based on Parked Cars
Parking lots (PLs) are usually full with cars. If these cars are formed into
a self-organizing vehicular network, they can be new kind of road side units
(RSUs) in urban area to provide communication data forwarding between mobile
terminals nearby and a base station. However cars in PLs can leave at any time,
which is neglected in the existing studies. In this paper, we investigate relay
cooperative communication based on parked cars in PLs. Taking the impact of the
car's leaving behavior into consideration, we derive the expressions of outage
probability in a two-hop cooperative communication and its link capacity.
Finally, the numerical results show that the impact of a car's arriving time is
greater than the impact of the duration the car has parked on outage
probability.Comment: 7 pages, 7 figures, accepted by ICACT201
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