CFO estimation in time-varying multipath fading channel for OFDM system using pilot symbols
| Autor: | Wei-Ju Li, 李韋儒 |
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| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 Orthogonal frequency-division multiplexing (OFDM) has developed into a popular scheme because OFDM system has high spectrum efficiency and effective to against multipath distortion, and need just only simple channel equalization in receiver. For OFDM communication systems, the orthogonality among subcarriers is lost in mobile applications due to carrier frequency offset (CFO) resulting from either transmitter-receiver local oscillator differences or Doppler shift caused by mobility. As a direct result, inter-carrier interference (ICI) is observed on each and every subcarrier, leading to significant performance degradation. This paper we will focus on study CFO estimation by using pilot symbols. In this paper, we study the CFO estimation in the presence of time-varying multipath fading channel and carrier frequency offset for OFDM system using pilot symbols. The concept of channel residual energy (CRE) is used to CFO estimation, pilot symbols used to rebuild of the channel frequency response. And also we proposed a new pilot symbols arrangement, and subcarrier residual energy (SRE) used to estimate CFO in frequency domain. Therefore, estimate in frequency domain can effectively reduce the system complexity. And finally, computer simulations result verify system performance analysis and comparison that CRE estimate CFO method and SRE estimate CFO method in time-varying multipath fading channel. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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