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The Estimation Method of Channel Quality 被引量:1
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作者 MENBao-hui CHENYing-jie 《Journal of Northeast Agricultural University(English Edition)》 CAS 2000年第1期33-37,共5页
On the basis of the introduction about water saving irrigation that works as a kind of new irrigation pattern,the method of anti-seep quality estimation of the conveying water and distributing channel which acts as an... On the basis of the introduction about water saving irrigation that works as a kind of new irrigation pattern,the method of anti-seep quality estimation of the conveying water and distributing channel which acts as an important engineering measure of water saving irrigation will be introduced in te paper.that is,by means of unit length of channel's water utilization coefficient(η 0)to estimate the quality of channel,and the calculative method has been explained by the example of an actual project.It can be referred to irrigational workers. 展开更多
关键词 water saving irrigation channel anti-seep unit length of channel's water utilization coefficient(η 0) channel quality estimation.
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Performance and Improvement of MCS Selection with Channel Quality Estimation Errors for HSDPA
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作者 贾民丽 匡镜明 +1 位作者 万蕾 费泽松 《Journal of Beijing Institute of Technology》 EI CAS 2006年第4期462-466,共5页
The throughput performance of modulation and coding schemes (MCS) selection with channel quality estimation errors (CQEE) is analyzed for high-speed downlink packet access (HSDPA). To reduce the loss of throughp... The throughput performance of modulation and coding schemes (MCS) selection with channel quality estimation errors (CQEE) is analyzed for high-speed downlink packet access (HSDPA). To reduce the loss of throughput caused by CQEE, the robust MCS selection method and adaptive MCS switching scheme are proposed. In addition, automatic repeat request (ARQ) scheme is used to improve the block error rate (BLER) performance. Simulation results show that the proposed methods decrease the throughput loss resulted from CQEE efficiently and BLER performance gets better with ARQ scheme. 展开更多
关键词 high-speed downlink packet access (HSDPA) modulation and coding scheme (MCS) channel quality estimation error (CQEE) automatic repeat request (ARQ)
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An Adaptive Management Strategy of CQI Channel Allocation in IEEE 802.16 Systems
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作者 王立磊 陈斌 徐惠民 《Journal of Donghua University(English Edition)》 EI CAS 2009年第5期533-538,共6页
IEEE 802.16 systems adopt a "semi-dynamic" allocation mechanism of channel quality indicator (CQI) channels.However,low utilization ratio of CQI channels reduces the spectrum efficiency.So we propose an adap... IEEE 802.16 systems adopt a "semi-dynamic" allocation mechanism of channel quality indicator (CQI) channels.However,low utilization ratio of CQI channels reduces the spectrum efficiency.So we propose an adaptive management strategy of CQI channels based on an analysis model named "toy brick model" to improve the efficiency.The simulation results validate the improvement. 展开更多
关键词 channel quality indicator CQI channelallocation IEEE 802. 16 systems management strategytoy brick model
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Energy Efficiency Maximization Strategy for Sink Node in SWIPT-Enabled Sensor-Cloud Based on Optimal Stopping Rules 被引量:2
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作者 Zhe Wang Lina Ge +2 位作者 Taoshen Li Guifen Zhang Min Wu 《China Communications》 SCIE CSCD 2021年第1期222-236,共15页
Leveraging energy harvesting abilities in wireless network devices has emerged as an effective way to prolong the lifetime of energy constrained systems.The system gains are usually optimized by designing resource all... Leveraging energy harvesting abilities in wireless network devices has emerged as an effective way to prolong the lifetime of energy constrained systems.The system gains are usually optimized by designing resource allocation algorithm appropriately.However,few works focus on the interaction that channel’s time-vary characters make the energy transfer inefficiently.To address this,we propose a novel system operation sequence for sensor-cloud system where the Sinks provide SWIPT for sensor nodes opportunistically during downlink phase and collect the data transmitted from sensor nodes in uplink phase.Then,the energy-efficiency maximization problem of the Sinks is presented by considering the time costs and energy consumption of channel detection.It is proved that the formulated problem is an optimal stopping process with optimal stopping rules.An optimal energy-efficiency(OEE)algorithm is designed to obtain the optimal stopping rules for SWIPT.Finally,the simulations are performed based on the OEE algorithm compared with the other two strategies to verify the effectiveness and gains in improving the system efficiency. 展开更多
关键词 sensor-cloud SWIPT optimal stopping theory energy efficiency channel quality
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Channel List Selection Based on Quality Prediction in WirelessHART Networks 被引量:1
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作者 Gongpu Chen Rui Ma +1 位作者 Mengdan Lei Xianghui Cao 《Journal of Communications and Information Networks》 2018年第3期49-56,共8页
WirelessHART is one of the most widely used technologies in industrial wireless networks.However,its performance is highly influenced by the quality of wireless channels.To improve the reliability of wireless communic... WirelessHART is one of the most widely used technologies in industrial wireless networks.However,its performance is highly influenced by the quality of wireless channels.To improve the reliability of wireless communications,WirelessHART employs channel blacklisting and channel hopping mechanisms,which highlights the importance of channel assessment.Traditional methods generally resort to packet reception ratio(PRR)of the previous time slot to assess and allocate channels,but this is not accurate.In this paper,we propose a learning-based framework for predicting the PRR,and on the basis of the predicted PRR,we develop a heuristic channel selection algorithm to confirm the channel list,which takes into account the balance of channel diversity and route diversity.Simulation results demonstrate that our algorithm outperforms existing ones in terms of achieved reliability. 展开更多
关键词 WIRELESSHART channel quality deep learning PREDICTION channel selection
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Is urban development an urban river killer? A case study of Yongding Diversion Channel in Beijing, China 被引量:8
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作者 Xi Wang Junqi Li +4 位作者 Yingxia Li Zhenyao Shen Xuan Wang Zhifeng Yang Inchio Lou 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第6期1232-1237,共6页
The high population and concrete environment alter urban areas by changing temperature, rainfall runoff, and water resource utilization activities. This study was conducted to investigate the water quality features of... The high population and concrete environment alter urban areas by changing temperature, rainfall runoff, and water resource utilization activities. This study was conducted to investigate the water quality features of the Yongding Diversion Channel in Beijing, China, and its relationship with rainfall and urban development. Monthly water quality data were obtained from April to October of 2004 at monitoring sites of Sanjiadian, Gaojing, Luodaozhuang, and Yuyuangtan. The monthly water quality grades from 2007 to 2011 were also investigated and compared with those of other rivers. Dissolved oxygen and pH showed greater decreases after one or two moderate rainfall events than several light rainfall events. The potassium permanganate index (CODMn), ammonia nitrogen (NH3-N) and total phosphorus (TP) increased more after several light rainfall events than after one or two moderate or heavy rainfall events. Pollutant concentrations (CODMn, NH3-N, TP) in downstream regions showed greater changes than those in upstream areas after heavy rainfall events. Intense human activities around the channel greatly influenced the water quality of the channel in rainy season because of runoff pollution; however, heavy rainfall had a strong dilution effect on the pollutant concentrations in rivers. Overall, urban development has obviously deteriorated the water quality of the Yongding Diversion Channel as indicated by an increase in the water quality index from 3.22 in 2008 to 4.55 in 2010. The Pearson correlation between monthly rainfall and water quality indices from 2007 to 2011 ranged from 0.1286 to 0.6968, generally becoming weaker as rainfall and rainfall runoff became more random and extreme. 展开更多
关键词 rainfallurban development water quality indices Yongding Diversion channel
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Addressing the CQI feedback delay in 5G/6G networks via machine learning and evolutionary computing
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作者 Andson Balieiro Kelvin Dias Paulo Guarda 《Intelligent and Converged Networks》 EI 2022年第3期271-281,共11页
5G networks apply adaptive modulation and coding according to the channel condition reported by the user in order to keep the mobile communication quality.However,the delay incurred by the feedback may make the channe... 5G networks apply adaptive modulation and coding according to the channel condition reported by the user in order to keep the mobile communication quality.However,the delay incurred by the feedback may make the channel quality indicator(CQI)obsolete.This paper addresses this issue by proposing two approaches,one based on machine learning and another on evolutionary computing,which considers the user context and signal-to-interference-plus-noise ratio(SINR)besides the delay length to estimate the updated SINR to be mapped into a CQI value.Our proposals are designed to run at the user equipment(UE)side,neither requiring any change in the signalling between the base station(gNB)and UE nor overloading the gNB.They are evaluated in terms of mean squared error by adopting 5G network simulation data and the results show their high accuracy and feasibility to be employed in 5G/6G systems. 展开更多
关键词 channel quality indicator(CQI)feedback delay 5G/6G networks machine learning evolutionary computing
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Performance of pond–wetland complexes as a preliminary processor of drinking water sources 被引量:12
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作者 Weidong Wang Jun Zheng +4 位作者 Zhongqiong Wang Rongbin Zhang Qinghua Chen Xinfeng Yu Chengqing Yin 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第1期119-133,共15页
Shijiuyang Constructed Wetland(110 hm^2) is a drinking water source treatment wetland with primary structural units of ponds and plant-bed/ditch systems. The wetland can process about 250,000 tonnes of source water ... Shijiuyang Constructed Wetland(110 hm^2) is a drinking water source treatment wetland with primary structural units of ponds and plant-bed/ditch systems. The wetland can process about 250,000 tonnes of source water in the Xincheng River every day and supplies raw water for Shijiuyang Drinking Water Plant. Daily data for 28 months indicated that the major water quality indexes of source water had been improved by one grade. The percentage increase for dissolved oxygen and the removal rates of ammonia nitrogen, iron and manganese were 73.63%, 38.86%, 35.64%, and 22.14% respectively. The treatment performance weight of ponds and plant-bed/ditch systems was roughly equal but they treated different pollutants preferentially. Most water quality indexes had better treatment efficacy with increasing temperature and inlet concentrations. These results revealed that the pond–wetland complexes exhibited strong buffering capacity for source water quality improvement. The treatment cost of Shijiuyang Drinking Water Plant was reduced by about 30.3%. Regional rainfall significantly determined the external river water levels and adversely deteriorated the inlet water quality, thus suggesting that the "hidden" diffuse pollution in the multitudinous stream branches as well as their catchments should be the controlling emphases for river source water protection in the future. The combination of pond and plant-bed/ditch systems provides a successful paradigm for drinking water source pretreatment. Three other drinking water source treatment wetlands with ponds and plant-bed/ditch systems are in operation or construction in the stream networks of the Yangtze River Delta and more people will be benefited. 展开更多
关键词 Pond–wetland combination Plant-bed/ditch system Constructed root channel technology Semi-subsurface flow wetland Weighted comprehensive water quality index
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