tailieunhanh - Báo cáo hóa học: " Research Article A Dynamic Tap Allocation for Concurrent CMA-DD Equalizers"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article A Dynamic Tap Allocation for Concurrent CMA-DD Equalizers | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2010 Article ID 278686 6 pages doi 2010 278686 Research Article A Dynamic Tap Allocation for Concurrent CMA-DD Equalizers Diego von B. M. Trindade Vitor Halmenschlager Leonardo Ortolan Maria C. F. De Castro Fernando C. C. De Castro and Fabricio Ourique Centro de Pesquisa em Tecnologias Wireless CPTW Pontificia Universidade Católica do Rio Grande do Sul PUCRS Avenda Ipiranga 6681 90619-000 Porto Alegre RS Brazil Correspondence should be addressed to Fabricio Ourique fourique@ Received 10 August 2010 Revised 23 September 2010 Accepted 20 October 2010 Academic Editor Christoph F. Mecklenbrauker Copyright 2010 Diego von B. M. Trindade et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. This paper proposes a dynamic tap allocation for the concurrent CMA-DD equalizer as a low complexity solution for the blind channel deconvolution problem. The number of taps is a crucial factor which affects the performance and the complexity of most adaptive equalizers. Generally an equalizer requires a large number of taps in order to cope with long delays in the channel multipath profile. Simulations show that the proposed new blind equalizer is able to solve the blind channel deconvolution problem with a specified and reduced number of active taps. As a result it minimizes the output excess mean square error due to inactive taps during and after the equalizer convergence and the hardware complexity as well. 1. Introduction The Concurrent Equalizer CEQ is based on a concurrent architecture which comprises the classical direct decision DD equalizer and Godard s widespread known constant modulus CMA blind equalizer 1 . In the CEQ architecture the DD branch is coordinated by the CMA branch gradient trajectory. Since the .