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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

NMCMA-SDD concurrent equalizer

Mayer, Kayol Soares 28 March 2018 (has links)
Submitted by PPG Engenharia El?trica (engenharia.pg.eletrica@pucrs.br) on 2018-04-23T19:26:15Z No. of bitstreams: 1 KAYOL_SOARES_MAYER_DIS.pdf: 19305237 bytes, checksum: 0750bd8f9d1820565918888661bc5acb (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-05-04T12:47:14Z (GMT) No. of bitstreams: 1 KAYOL_SOARES_MAYER_DIS.pdf: 19305237 bytes, checksum: 0750bd8f9d1820565918888661bc5acb (MD5) / Made available in DSpace on 2018-05-04T13:13:01Z (GMT). No. of bitstreams: 1 KAYOL_SOARES_MAYER_DIS.pdf: 19305237 bytes, checksum: 0750bd8f9d1820565918888661bc5acb (MD5) Previous issue date: 2018-03-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Em sistemas de comunica??o digital sem fio, o sinal transmitido pode ser afetado por v?rias fontes de distor??o, sendo as mais significantes o ru?do gaussiano branco aditivo (AWGN), multipercurso e efeito Doppler. Em ambientes onde a resposta de impulso do canal de comunica??o ? vari?vel no tempo, como em comunica??es m?veis, a distor??o por multipercurso ? din?mica. Juntamente com o efeito Doppler, o multipercurso din?mico pode at? mesmo eventualmente interromper completamente o link de comunica??o sem fio. Para minimizar este problema, equalizadores de canais autodidatas s?o usados para mitigar os efeitos de multipercurso e Doppler. Neste contexto, esta disserta??o prop?e um novo equalizador de canal autodidata (blind), baseado no algoritmo de m?dulo constante modificado n?o linear (NMCMA) e no equalizador Soft Direct Decision (SDD) em uma arquitetura concorrente. Este novo equalizador concorrente NMCMA-SDD ? comparado com o estado da arte, o equalizador concorrente com algoritmo de m?dulo constante (CMA)-SDD, operando sob os chamados "Brazil channels A-E", proposto pela Uni?o Internacional das Telecomunica??es (UIT). O equalizador proposto apresenta resultados significativos em compara??o com o estado da arte, possibilitando a opera??o em links de comunica??o sem fio entre ve?culos a?reos n?o tripulados (UAVs), ve?culos terrestres e em outros cen?rios de comunica??o din?mica. / In wireless digital communication systems, the transmitted signal may be affected by several sources of distortion, the most significant being Additive Whit Gaussian Noise (AWGN), multipath and Dopplr effect. In environmets where the impulse response of the communication channel is time variant, as in mobile communications, the multipath distortion is dynamic. Together with the Doppler effect, the dynamic multipath may even completely interrupt the wireless communication link. In order to solve this issue, blind channel equalizers are used to mitigate the multipath and Doppler effects. In this context, this dissertation proposes a novel blind channel equalizer, based on the Nonlinear Modified Constant Modulus Algorithm (NMCMA) and on the Soft Direct Desicion (SDD) equalizers in a concurrent architecture. This novel NMCMA-SDD concurrent equalizer is compared with the state of the art, the Constant Modulus Algorithm (CMA)-SDD concurrent equalizer, over the so-called "Brazil channels A-E", proposed by the International Telecommunication Union (ITU). The proposed equalizer presents significant results when compared with the state of the art, making possible its operation in wireless communication links for Unmanned Aerial Vehicles (UAVs), terrestrial vehicles, and others dynamic communication scenarios.

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