Sun, 27 Jul 2008 07:50:34 BST CiteULike: dcastro's Zou http://www.citeulike.org/user/dcastro/author/Zou CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dcastro/article/2776174 <i>Broadcasting, IEEE Transactions on, Vol. 41, No. 1. (1995), pp. 1-8.</i><br /><br />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 COFDM: an overview WY Zou Yiyan Wu doi:10.1109/11.372015 Broadcasting, IEEE Transactions on, Vol. 41, No. 1. (1995), pp. 1-8. 2008-05-09T15:41:55-00:00 1995 Broadcasting, IEEE Transactions on 41 1 1 8 ofdm overview http://www.citeulike.org/user/dcastro/article/1876649 <i>Journal of Zhejiang University - Science A, Vol. 8, No. 10. (29 October 2007), pp. 1568-1572.</i><br /><br />Abstract  Broadband phase shifters are mostly proposed and fabricated based on the scheme proposed by Shiffman, which uses a coupled line with far ends connected together and a uniform transmission line to give a differential phase shift. Based on the unique dispersion property of the composite right/left-handed (CRLH) metamaterial structure, a new configuration is presented in this paper for fabricating the broadband differential phase shifter, which employs a novel CRLH metamaterial structure as one of the differential phase-shift arms, instead of the conventional coupled line. The new circuit can achieve a phase shift of 90� in an operational bandwidth as broad as one octave and its phase deviations are quite small. An original design of the novel broadband phase shifter is presented, in which the artificial CRLH structure was implemented by microstrip quasi-lumped elements. Both the simulated and measured results of the 90� broadband differential phase shifter are presented. A new broadband differential phase shifter fabricated using a novel CRLH structure Yong-Zhuo Zou Zhi-Li Lin Ti Ling Jun Yao Sailing He doi:10.1631/jzus.2007.A1568 Journal of Zhejiang University - Science A, Vol. 8, No. 10. (29 October 2007), pp. 1568-1572. 2007-11-07T07:47:38-00:00 2007 Journal of Zhejiang University - Science A 8 10 1568 1572 broadband crlh phase-shifter structure