A Study on Frame Format for 802.16d/e OFDM System in High Speed Train Environment
Date Issued
2007
Date
2007
Author(s)
Cheng, Hsiu-Cheng
DOI
zh-TW
Abstract
With the rapid growth of wireless communications and high speed rail, the need for high speed data transmission in high speed train environment is increased. Orthogonal Frequency Division Multiplexing (OFDM) is recently becoming very popular for achieving high data rates due to its resistance to ISI. OFDM has also been chosen as the transmission method for many standards, such as the IEEE 802.11 and 802.16. The accuracy of pilot-aided channel estimation at a desired Doppler frequency is highly dependent on how the pilots are arranged. In this paper, we describe the effect of Doppler frequency on different pilot arrangements in wireless OFDM systems and simulate the performance using the parameters of the IEEE 802.16 standard in high mobility environment. According to sampling theorem and channel parameters, we propose a new pilot insertion scheme and compare it with conventional 802.16 frame format. In the end, we use characterization of rail environment to improve system performance.
Subjects
OFDM
802.16
導航符號排列方式
鐵路環境特性
high speed rail
pilot arrangement
characterization of rail environment
Type
thesis