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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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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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