The directional neighbor discovery problem,i.e,spatial rendezvous,is a fundamental problem in millimeter wave(mmWave)wireless networks,where directional transmissions are used to overcome the high attenuation.The chal...The directional neighbor discovery problem,i.e,spatial rendezvous,is a fundamental problem in millimeter wave(mmWave)wireless networks,where directional transmissions are used to overcome the high attenuation.The challenge is how to let the transmitter and the receiver beams meet in space under deafness caused by directional transmission and reception,where no control channel,prior information,and coordination are available.In this paper,we present a Hunting based Directional Neighbor Discovery(HDND)scheme for ad hoc mmWave networks,where a node follows a unique sequence to determine its transmission or reception mode,and continuously r0-tates its directional beam to scan the neighborhood for other mmWave nodes.Through a rigorous analysis,we derive the conditions for ensured neighbor discovery,as well as a bound for the worst-case discovery time and the impact of sidelobes.We validate the analysis with extensive simulations and demonstrate the superior perfor-mance of the proposed scheme over several baseline schemes.展开更多
This paper proposes a new dielectric resonator antenna(DRA)design that can generate circularly polarized(CP)triple-band signals.Atripleband CP DRA antenna fed by a probe feed system is achieved with metal strips struc...This paper proposes a new dielectric resonator antenna(DRA)design that can generate circularly polarized(CP)triple-band signals.Atripleband CP DRA antenna fed by a probe feed system is achieved with metal strips structure on side of DRA structure.The design start with conventional rectangular DRA with F shaped metal strips on DRA structure alongside the feed.Then,the F metal strip is enhanced by extending the length of the metal strip to obtain wider impedance bandwidth.Further improvement on the antenna performance is observed by improvised the conventional DRA structure.The method of removing part of DRA bottom resulted to higher antenna gain with triple band CP.The primary features of the proposed DRA include wide impedance matching bandwidth(BW)and broadband circular polarization(CP).The primary features of the proposedDRAinclude wide impedance matching bandwidth(BW)and broadband circular polarization(CP).The CP BW values recorded by the proposed antenna were∼11.27%(3.3–3.65 GHz),12.18%(4.17–4.69 GHz),and 1.74%(6.44–6.55 GHz)for impedance-matching BW values of 35.4%(3.3–4.69 GHz),1.74%(5.36–5.44 GHz),and 1.85%(6.41–6.55 GHz)with peak gains of 6.8 dBic,7.6 dBic,and 8.5 dBic,respectively,in the lower,central,and upper bands.The prototype of the proposed antenna geometry was fabricated and measured.A good agreement was noted between the simulated and the measured results.展开更多
近年来,广播电视播出系统对不间断电源(Uninterruptible Power Supply,UPS)的需求不断增长。优化UPS电源系统的配置策略,以提升其供电效能,已经成为一个值得深入研究的问题。首先,简要阐述UPS电源系统工作原理,随后提出一种创新的UPS电...近年来,广播电视播出系统对不间断电源(Uninterruptible Power Supply,UPS)的需求不断增长。优化UPS电源系统的配置策略,以提升其供电效能,已经成为一个值得深入研究的问题。首先,简要阐述UPS电源系统工作原理,随后提出一种创新的UPS电源系统配置策略。其次,对不同供配电环境的冗余配置方式进行对比分析,以确定最优配置方案。最后,探讨广播电视UPS电源系统蓄电池容量的计算方法,并针对现有方法提出修正建议。展开更多
通过深入分析中国数字广播(China Digital Radio,CDR)编码技术的基础理论,重点研究数字广播音频增强编码(Digital Radio Audio Plus,DRA+)信源编码的低码率音频压缩和多声道编码优化策略,分析低密度奇偶校验(Low Density Parity Check,L...通过深入分析中国数字广播(China Digital Radio,CDR)编码技术的基础理论,重点研究数字广播音频增强编码(Digital Radio Audio Plus,DRA+)信源编码的低码率音频压缩和多声道编码优化策略,分析低密度奇偶校验(Low Density Parity Check,LDPC)信道编码和编码参数自适应调整在应急广播中的具体应用。实验测试验证了CDR编码技术在应急场景下的优异性能,DRA+编码在保证音质前提下实现了高效压缩,LDPC编码显著提升了系统抗干扰能力。自适应调整机制能够根据应急环境动态配置编码参数,确保传输稳定性,为CDR编码技术在应急广播中的推广应用提供了理论依据和实践指导。展开更多
为提升传输质量和频谱利用效率,研究卫星通信技术在广播电视传输发射中的应用。首先分析卫星通信系统的基本构成及关键技术,其次探讨卫星通信技术的具体应用场景,最后从信号质量提升和频谱效率改进两个方面分析卫星通信系统的性能优化...为提升传输质量和频谱利用效率,研究卫星通信技术在广播电视传输发射中的应用。首先分析卫星通信系统的基本构成及关键技术,其次探讨卫星通信技术的具体应用场景,最后从信号质量提升和频谱效率改进两个方面分析卫星通信系统的性能优化方法。研究表明,现代卫星通信技术通过应用自适应调制编码、密度奇偶校验码(Low Density Parity Check Code,LDPC)和BCH(Bose-Chaudhuri-Hocquenghem)级联编码等先进技术,显著提升了传输系统的频谱效率和抗干扰能力;通过合理优化系统性能参数,可使频谱利用效率提升15%以上,为广播电视传输提供了更可靠的技术支持。展开更多
基金supported in part by the NSF under Grants ECCS-1923717 and CNS-1320472the Wireless Engineering Research and Education Center,Auburn University,Auburn,AL,USA.
文摘The directional neighbor discovery problem,i.e,spatial rendezvous,is a fundamental problem in millimeter wave(mmWave)wireless networks,where directional transmissions are used to overcome the high attenuation.The challenge is how to let the transmitter and the receiver beams meet in space under deafness caused by directional transmission and reception,where no control channel,prior information,and coordination are available.In this paper,we present a Hunting based Directional Neighbor Discovery(HDND)scheme for ad hoc mmWave networks,where a node follows a unique sequence to determine its transmission or reception mode,and continuously r0-tates its directional beam to scan the neighborhood for other mmWave nodes.Through a rigorous analysis,we derive the conditions for ensured neighbor discovery,as well as a bound for the worst-case discovery time and the impact of sidelobes.We validate the analysis with extensive simulations and demonstrate the superior perfor-mance of the proposed scheme over several baseline schemes.
文摘This paper proposes a new dielectric resonator antenna(DRA)design that can generate circularly polarized(CP)triple-band signals.Atripleband CP DRA antenna fed by a probe feed system is achieved with metal strips structure on side of DRA structure.The design start with conventional rectangular DRA with F shaped metal strips on DRA structure alongside the feed.Then,the F metal strip is enhanced by extending the length of the metal strip to obtain wider impedance bandwidth.Further improvement on the antenna performance is observed by improvised the conventional DRA structure.The method of removing part of DRA bottom resulted to higher antenna gain with triple band CP.The primary features of the proposed DRA include wide impedance matching bandwidth(BW)and broadband circular polarization(CP).The primary features of the proposedDRAinclude wide impedance matching bandwidth(BW)and broadband circular polarization(CP).The CP BW values recorded by the proposed antenna were∼11.27%(3.3–3.65 GHz),12.18%(4.17–4.69 GHz),and 1.74%(6.44–6.55 GHz)for impedance-matching BW values of 35.4%(3.3–4.69 GHz),1.74%(5.36–5.44 GHz),and 1.85%(6.41–6.55 GHz)with peak gains of 6.8 dBic,7.6 dBic,and 8.5 dBic,respectively,in the lower,central,and upper bands.The prototype of the proposed antenna geometry was fabricated and measured.A good agreement was noted between the simulated and the measured results.
文摘近年来,广播电视播出系统对不间断电源(Uninterruptible Power Supply,UPS)的需求不断增长。优化UPS电源系统的配置策略,以提升其供电效能,已经成为一个值得深入研究的问题。首先,简要阐述UPS电源系统工作原理,随后提出一种创新的UPS电源系统配置策略。其次,对不同供配电环境的冗余配置方式进行对比分析,以确定最优配置方案。最后,探讨广播电视UPS电源系统蓄电池容量的计算方法,并针对现有方法提出修正建议。
文摘通过深入分析中国数字广播(China Digital Radio,CDR)编码技术的基础理论,重点研究数字广播音频增强编码(Digital Radio Audio Plus,DRA+)信源编码的低码率音频压缩和多声道编码优化策略,分析低密度奇偶校验(Low Density Parity Check,LDPC)信道编码和编码参数自适应调整在应急广播中的具体应用。实验测试验证了CDR编码技术在应急场景下的优异性能,DRA+编码在保证音质前提下实现了高效压缩,LDPC编码显著提升了系统抗干扰能力。自适应调整机制能够根据应急环境动态配置编码参数,确保传输稳定性,为CDR编码技术在应急广播中的推广应用提供了理论依据和实践指导。
文摘为提升传输质量和频谱利用效率,研究卫星通信技术在广播电视传输发射中的应用。首先分析卫星通信系统的基本构成及关键技术,其次探讨卫星通信技术的具体应用场景,最后从信号质量提升和频谱效率改进两个方面分析卫星通信系统的性能优化方法。研究表明,现代卫星通信技术通过应用自适应调制编码、密度奇偶校验码(Low Density Parity Check Code,LDPC)和BCH(Bose-Chaudhuri-Hocquenghem)级联编码等先进技术,显著提升了传输系统的频谱效率和抗干扰能力;通过合理优化系统性能参数,可使频谱利用效率提升15%以上,为广播电视传输提供了更可靠的技术支持。
