A Study on Turbo Equalizer Combined with OFDM System in Very High Mobility Environment
Date Issued
2007
Date
2007
Author(s)
Lin, Chien-Yang
DOI
zh-TW
Abstract
Turbo equalization is a new method which combines channel equalization and channel coding .It is different from traditional equalization. The performance of turbo equalizer (TE) with single carrier system in very high mobility environment is excellent. So we try to use TE combined with multicarrier system ,such as Orthogonal Frequency Division Multiplexing (OFDM), in very high mobility environment. OFDM system would suffer gravely from Intercarrier Interference effect (ICI) in very high mobility environment, so we hope that TE could help OFDM system lower its Bit Error Rate (BER). At first, we simulate TE combined with OFDM system with small FFT (Fast Fourier Transform) size in very high mobility environment to make sure about its feasibility. Then we substitute the low FFT size for higher FFT size. Secondly, we use the high speed rail’s characterization of the fixed path to demonstrate two kinds of channel information for channel estimation. In the end, we change the ratio of data symbols and training segments in frame format in order to improve our system useful data rate.
Subjects
渦輪等化器
正交分頻多工系統
子載波間干擾
Turbo equalizer
very high mobility environment
OFDM
ICI
Type
thesis