共查询到20条相似文献,搜索用时 46 毫秒
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Zi-Wei Zheng Zhi-Xing Yang Chang-Yong Pan Yi-Sheng Zhu 《Broadcasting, IEEE Transactions on》2005,51(2):237-243
As an effective technique for combating multipath fading and for high-bit-rate transmission over wireless channels, orthogonal frequency-division multiplexing (OFDM) is extensively used in modern digital television terrestrial broadcasting (DTTB) systems, such as the cyclic prefix OFDM (CP-OFDM) based DVB-T DTTB systems and the time domain synchronous OFDM (TDS-OFDM) based DMB-T DTTB systems, to support high performance bandwidth-efficient multimedia services. OFDM-based DTTB systems are very sensitive to the nonlinear distortion at the transmitter and the imperfect parameters estimation at the receiver. In this paper, the combined effects of nonlinear distortion and imperfect parameters estimation on the performance of the OFDM-based DTTB systems are investigated, a closed form of symbol error probability of the OFDM-based DTTB systems with nonlinear distortion and imperfect parameters estimation is derived. Theoretical results show closely matching with those obtained by simulations for both the CP-OFDM based DVB-T DTTB systems and the TDS-OFDM based DMB-T DTTB systems. 相似文献
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Zi-Wei Zheng Zhi-Xing Yang Chang-Yong Pan Yi-Sheng Zhu 《Broadcasting, IEEE Transactions on》2004,50(2):148-153
As an effective technique for combating multipath fading and for high-bit-rate transmission over wireless channels, orthogonal frequency-division multiplexing (OFDM) is extensively used in modern digital television terrestrial broadcasting (DTTB) systems to support high performance bandwidth-efficient multimedia services. In this paper, novel synchronization schemes, including timing, frequency offset estimation, and phase error tracking, are proposed for the time domain synchronous OFDM (TDS-OFDM) based DTTB systems. Simulations under different channel situations verify the efficiency of the proposed schemes. 相似文献
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Sunghyun Cho Soonbae Ji Intae Hwang Cheolwoo You 《Wireless Personal Communications》2014,78(1):561-577
Digital terrestrial television is a modern broadcasting technology that has permitted broadcasters to offer television service with excellent image and sound quality. Many countries have been assigned a new digital television standardization process and many studies are underway regarding digital multimedia broadcasting technology. This paper investigates the utilization of a coded cooperative multiple-input and multiple-output (MIMO) transmission scheme in modern digital broadcasting systems to achieve additional transmit diversity and coding gains. The main idea of this work is the implementation of a coded cooperative MIMO scheme based on a low-density parity check code. A coded cooperative transmission can obtain a robust forward error correction. In this way, it is possible to achieve more stable system performance and improved mobility for next generation handheld systems. In order to show the potential for practical implementation, the performance of the proposed method is evaluated on the basis of the Digital Video Broadcasting-Second Generation Terrestrial (DVB-T2) system. The simulation results show that the proposed scheme can be utilized for the development of future DVB broadcasting systems that should support high mobility handheld devices, such as the Digital Video Broadcasting–Next Generation Handheld (DVB–NGH) system. 相似文献
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DVB-T: the COFDM-based system for terrestrial television 总被引:1,自引:0,他引:1
In early 1996, the European DVB (Digital Video Broadcasting) Project finalised what is now called the `common 2k/8k specification' for terrestrial television transmission. This specification is an important cornerstone of digital video broadcasting in Europe and numerous other countries in the world. Called DVB-T, it is based on the channel-coding algorithms the DVB Project had earlier devised for digital television on cable and satellite. The modulation scheme that is used for DVB-T is OFDM (orthogonal frequency division multiplexing), which when used in conjunction with channel coding is known as COFDM. Two variants are described, one employing 1705 individual carriers in an 8 MHz channel (`2k variant'), the other employing 6817 carriers (`8k variant'). Each individual carrier can be modulated either by QPSK, 16-QAM, 64-QAM or hierarchical modulation 相似文献
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We solve optimal symbol dimensions for a recently introduced two-dimensional orthogonal frequency division multiplexing (2D OFDM) scheme with a two-dimensional cyclic prefix (2D CP). The 2D OFDM technique is shown to improve the rate of a wireless relaying system if the channel coherence time is at least nine times longer than the channel impulse response. Furthermore, feasibility and application scenarios of 2D OFDM are discussed using the parameters of terrestrial digital video broadcasting systems (DVB-T/H) as examples. 相似文献
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Digital video broadcasting 总被引:1,自引:0,他引:1
A new kind of “wireless video” is currently entering consumers' homes-digital television. The term digital video broadcasting (DVB) is used as a synonym for digital television in many countries of the world. Whereas one may tend to think that digital television means just a new, digital, form of signal representation not necessarily affecting the information content of what one has always called TV, the truth is that digital television becomes multiple-channel data broadcasting. This article reviews some of the results of the work in the worldwide DVB Project and explains some of the fundamental concepts behind the work of this group. It then concentrates on the terrestrial transmission system (DVB-T) as one example of the many transmission technologies DVB has developed over the last few years. The COFDM modulation scheme which is a key ingredient of DVB-T is described in some detail. The performance of the system is presented. The use of DVB for data broadcasting and the accompanying return channel technologies are explained 相似文献
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文中首先描述了OFDM在数字通信中的应用,接着介绍了Reed Solomon(RS)编码,重点研究了Turbo码及其解码算法,提出了一种应用Turbo码和Rs码的级联码结合OFDM调制的前向纠错方案,分析了该方案用于数字视频广播地面信道(DVB-T)的性能.通过在加性高斯白噪声(Addittve White Gaussian Noisc,AWGN)信道上的仿真,验证了该方案比目前DVB-T标准中的卷积码方案有更好的性能.仿真结果表明,应用Turbo码仅在解码迭代次数增加几次的情况下,系统性能有显著的提高. 相似文献
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《Broadcasting, IEEE Transactions on》2009,55(3):607-615
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The DVB-H Mobile Broadcast Standard 总被引:1,自引:0,他引:1
The digital video broadcasting-handheld (DVB-H) standard is one of the latest transmission standards developed by the digital video broadcasting (DVB) Project. DVB-H, which is based on the standard for digital terrestrial television (DVB-T), offers mobile television and other broadcasting services on small portable devices such as mobile phones. This article presents an overview of the DVB-H standard with respect to structure, features, technology, performance, and resources. 相似文献
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《Broadcasting, IEEE Transactions on》2008,54(4):799-805
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The combination of high capacity, signal robustness, and worldwide acceptance have made digital terrestrial broadcasting (DVB-T) one of today's more promising technologies, while newly adopted standards support the integration of digital television programs and data services within a single multiplex, offered to both stationary and mobile end users. The paper addresses the issue of optimal bit rate allocation among DTV and IP services within the DVB-T multiplex, and demonstrates a novel configuration providing real-time sharing of the available bandwidth via an algorithm based on service hierarchy and perceptual quality assessment. The architecture and performance of a fully functional DVB-T testbed developed on this concept is also presented. 相似文献
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COFDM: an overview 总被引:4,自引:0,他引:4
The research and development of OFDM/COFDM for digital television broadcasting has received considerable attention and has made a great deal of progress in Europe. OFDM/COFDM has already been implemented in digital audio broadcasting and is being considered for terrestrial digital television and HDTV broadcasting. The advantages of COFDM claimed by the advocates in Europe have also caught the attention of US broadcasters and generated enthusiasm although a digital modulation technique called 8-VSB has been selected by the FCC Advisory Committee on Advanced Television Service (ACATS) for the final testing. There is considerable debate in the industry over the use of COFDM vs. VSB or QAM for terrestrial HDTV broadcasting. In this paper, the history of research and development on OFDM and COFDM is reviewed. Then, the basic principles, performance and implementation of OFDM and COFDM are examined. Analysis is given to enable the selection of key elements for meeting the constraints of the required applications. Based on the ATV channel model, performance expectation of COFDM under imperfect channel conditions and implementation issues are examined in details 相似文献
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《Broadcasting, IEEE Transactions on》2009,55(4):719-730
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Zi-Wei Zheng 《Wireless Personal Communications》2011,59(2):159-171
As an effective technique for combating multipath fading and for high-bit-rate transmission over wireless channels, orthogonal
frequency division multiplexing (OFDM) is extensively used in high-rate wireless communication systems, such as, the wireless
local area network (WLAN) and the digital television terrestrial broadcasting (DTTB) systems, to support high performance
bandwidth-efficient multimedia services. Multiple antennas and transmit or receive diversity, multiple-input multiple-output
orthogonal frequency division multiplexing (MIMO-OFDM), can be used to improve error performance and capacity of wireless
systems. In this paper, we consider the effects of carrier frequency offset and channel estimation errors on the performance
of MIMO-OFDM systems in spatially correlated channels. Theoretical calculations and computer simulations are done to analyze
the performance degradation of MIMO-OFDM systems in spatially correlated channels due to carrier frequency offset and channel
estimation errors, and the theoretical and simulated results match well. 相似文献