期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
New Precoded Spatial-Multiplexing for an Erasure Event in Single Frequency Networks
1
作者 hojun kim seyoung kim +2 位作者 yulong shang seunghyeon kim taejin jung 《China Communications》 SCIE CSCD 2018年第4期130-140,共11页
In this paper, we propose a new spatial-multiplexing(SM) scheme employing an orthogonal precoder over Rayleigh-fading channels for an erasure event in single frequency networks(SFN). To optimize the precoder, the aver... In this paper, we propose a new spatial-multiplexing(SM) scheme employing an orthogonal precoder over Rayleigh-fading channels for an erasure event in single frequency networks(SFN). To optimize the precoder, the average bit error rate(BER) is evaluated and minimized through a mathematical analysis. Compared to an ordinary SM, the proposed scheme guarantees identical BER performance under non-erasure fading channels and achieves a greatly improved performance under erasure fading channels, especially for a higher erasure-ratio and SNR values. This improvement is mainly due to the increase in the diversity gain incurred by the optimized precoder over the erasure event. We also compare the performance of the proposed SM to that of the conventional constellation-rotation(CR) scheme applied to the single antenna SFN systems. The results of a computer simulation show that the performance of the new scheme is more effective than that of a conventional CR across all simulation cases. 展开更多
关键词 Spatial-multiplexing single fre-quency network Rayleigh fading constella-tion-rotation broadcasting systems.
下载PDF
Monitoring continuous k-nearest neighbor queries in the hybrid wireless network
2
作者 Young-Mo KWON HaRim JUNG Yon Dohn CHUNG 《Journal of Zhejiang University-Science C(Computers and Electronics)》 SCIE EI 2011年第3期213-220,共8页
In a mobile/pervasive computing environment,one of the most important goals of monitoring continuous spatial queries is to reduce communication cost for location-updates.Existing work uses many cellular wireless conne... In a mobile/pervasive computing environment,one of the most important goals of monitoring continuous spatial queries is to reduce communication cost for location-updates.Existing work uses many cellular wireless connections,which would easily become the performance bottleneck of the overall system.This paper introduces a novel continuous kNN query monitoring method to reduce communication cost in the hybrid wireless network,where the moving objects in the wireless broadcasting system construct the ad-hoc network.Simulation results prove the efficiency of the proposed method,which leverages the wireless broadcasting channel as well as the WiFi link to alleviate the burden on the cellular uplink communication cost. 展开更多
关键词 Continuous kNN query monitoring Ad-hoc networks Wireless broadcasting systems
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部