CFO Estimation for Polymomial Cancellation Coded OFDM Systems

• Main Author: 洪千雅
• Other Authors: 蘇育德
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/96867083432552317601

碩士 === 國立交通大學 === 電機學院通訊與網路科技產業專班 === 96 === Orthogonal Frequency Division Multiplexing (OFDM) is being considered as a promising transmission technique. However, a carrier frequency offset (CFO) between the transmitter and receiver will results in ICI and thus destroy the orthogonality of the subcarrier and degrades the performance. ICI leads to attenuation and phase rotation of desired signal on each subcarrier. These impairments have already motivated several studies to find solutions. Among the several ICI reduction schemes, ICI self-cancellation or polynomial cancellation coding (PCC) scheme has received much attention due to its simplicity and its high robustness to frequency offset errors. However, for large CFO, PCC can only eliminate ICI to a certain extent. Thus, we propose new methods of PCC based CFO estimation to eliminate ICI for either low or high CFOs. First, we use PCC as precoding scheme and get the initial decoded data. Then CFO estimation is done by making use of the decode data. CFO estimation and compensation from PCC can overcome the drawback of PCC that only a certain part of ICI can be eliminated when CFO is large.