详细探讨基于第二代地面数字视频广播(Digital Video Broadcasting-Terrestrial 2,DVB-T2)标准的数字广播信号抗干扰技术,包括多天线技术(Multiple-Input Multiple-Output,MIMO)在抗干扰中的应用、干扰识别与抑制算法的开发、信号纠错...详细探讨基于第二代地面数字视频广播(Digital Video Broadcasting-Terrestrial 2,DVB-T2)标准的数字广播信号抗干扰技术,包括多天线技术(Multiple-Input Multiple-Output,MIMO)在抗干扰中的应用、干扰识别与抑制算法的开发、信号纠错与恢复机制的优化及卷积编码与交织技术的改进。通过理论分析与技术应用测试,显示这些创新措施可显著提高广播信号的稳定性和抗干扰能力,为数字广播系统在多变环境下的可靠运行提供有效支持。展开更多
As the 2nd generation digital terrestrial television broadcasting(DTTB)standard,digital terrestrial/television multimedia broadcasting-advanced(DTMB-A)can provide higher spectrum efficiency and transmission reliabilit...As the 2nd generation digital terrestrial television broadcasting(DTTB)standard,digital terrestrial/television multimedia broadcasting-advanced(DTMB-A)can provide higher spectrum efficiency and transmission reliability by adopting flexible frame structure and advanced forward error correction coding compared with the 1 st generation DTTB systems.In order to increase the flexibility and robustness of the DTTB network,the frequency reuse scheme of factor one(reuse-1)is proposed,where the same RF channel is used by different stations covering the adjacent service areas.However,it demands a very low carrier-tonoise ratio(C/N)threshold below 0 dB at the DTTB physical layer.In this paper,a robust broadcasting technique is proposed based on DTMB-A with newly designed low-rate low density parity check(LDPC)codes.By adopting quasi-cyclic(QC)Raptor-like structure and progressive lifting method,the high performance low-rate LDPC codes are designed supporting multiple code lengths.Both density-evolution analyses and laboratory measurements demonstrate that DTMB-A with low-rate coding can complete the demodulation reliably with the C/N threshold below0 d B,which is one important necessary condition to support frequency reuse-1 scheme.展开更多
广播电视同步数字体系(Synchronous Digital Hierarchy,SDH)数字微波传输系统在远距离、大容量传输等方面有着天然的技术优势,但由于传输过程中需要完成适配、复用和中继等信号处理步骤,导致系统运行时极易出现故障现象。因此,围绕SDH...广播电视同步数字体系(Synchronous Digital Hierarchy,SDH)数字微波传输系统在远距离、大容量传输等方面有着天然的技术优势,但由于传输过程中需要完成适配、复用和中继等信号处理步骤,导致系统运行时极易出现故障现象。因此,围绕SDH数字微波传输系统的设备组成、工作原理及功能模块展开深入研究,分析论证系统运行中常见的故障,解析故障原因并给出处置策略,以期为技术人员提供参考,提升广播电视SDH数字微波传输系统的稳定性和可靠性。展开更多
文摘详细探讨基于第二代地面数字视频广播(Digital Video Broadcasting-Terrestrial 2,DVB-T2)标准的数字广播信号抗干扰技术,包括多天线技术(Multiple-Input Multiple-Output,MIMO)在抗干扰中的应用、干扰识别与抑制算法的开发、信号纠错与恢复机制的优化及卷积编码与交织技术的改进。通过理论分析与技术应用测试,显示这些创新措施可显著提高广播信号的稳定性和抗干扰能力,为数字广播系统在多变环境下的可靠运行提供有效支持。
基金supported in part by the National Natural Science Foundation of China(NSFC)under Grant 61931015the Peng Cheng Laboratory under Grant PCL2021A10+1 种基金the Science,Technology and Innovation Commission of Shenzhen Municipality(No.JSGG20201103095805015)sponsored by Tsinghua University-Yunnan Mobile Digital TV Company Ltd.,Joint Research Center(JCICBN)。
文摘As the 2nd generation digital terrestrial television broadcasting(DTTB)standard,digital terrestrial/television multimedia broadcasting-advanced(DTMB-A)can provide higher spectrum efficiency and transmission reliability by adopting flexible frame structure and advanced forward error correction coding compared with the 1 st generation DTTB systems.In order to increase the flexibility and robustness of the DTTB network,the frequency reuse scheme of factor one(reuse-1)is proposed,where the same RF channel is used by different stations covering the adjacent service areas.However,it demands a very low carrier-tonoise ratio(C/N)threshold below 0 dB at the DTTB physical layer.In this paper,a robust broadcasting technique is proposed based on DTMB-A with newly designed low-rate low density parity check(LDPC)codes.By adopting quasi-cyclic(QC)Raptor-like structure and progressive lifting method,the high performance low-rate LDPC codes are designed supporting multiple code lengths.Both density-evolution analyses and laboratory measurements demonstrate that DTMB-A with low-rate coding can complete the demodulation reliably with the C/N threshold below0 d B,which is one important necessary condition to support frequency reuse-1 scheme.
文摘广播电视同步数字体系(Synchronous Digital Hierarchy,SDH)数字微波传输系统在远距离、大容量传输等方面有着天然的技术优势,但由于传输过程中需要完成适配、复用和中继等信号处理步骤,导致系统运行时极易出现故障现象。因此,围绕SDH数字微波传输系统的设备组成、工作原理及功能模块展开深入研究,分析论证系统运行中常见的故障,解析故障原因并给出处置策略,以期为技术人员提供参考,提升广播电视SDH数字微波传输系统的稳定性和可靠性。
文摘对广播电视无线数字化系统中应用到的多项核心技术进行了深入剖析和探讨。首先,分析调制技术,介绍了调频(Frequency Modulation,FM)/调幅(Amplitude Modulation,AM)调制的原理,并阐述了数字调制技术如正交幅度调制(Quadrature Amplitude Modulation,QAM)、正交频分多址(Orthogonal Frequency Division Multiple Access,OFDMA)等的工作机制与优势。其次,探讨数字电视广播的传输技术,包括地面数字电视传输标准和卫星传输技术。再次,重点分析音视频编码、信道编码等信号处理技术,说明它们在压缩数据、抗干扰方面的作用。最后,介绍多频网(Multi Frequency Network,MFN)和单频网(Single Frequency Network,SFN)两种网络配置方式的不同。通过应用这些技术,我国已构建起规模庞大、技术先进的广播电视无线发射网络,为人们获取音、视频信息提供保障。
