在正交分頻多功系統下使用基於子空間和導引訊號的穿插對相位雜訊的估計和減緩

• Main Authors: Tseng, Yu-Hsiang, 曾裕翔
• Other Authors: Hong, Yao-Win Peter
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/25840887424805308032

碩士 === 國立清華大學 === 電機工程學系 === 99 === Orthogonal frequency division multiplexing (OFDM) have been widely adopted in modern wireless systems due to its ability to combat intersymbol interference (ISI) and frequency selectivity. However, OFDM systems are extremely sensitive to phase noise that may exist during the up and down-conversion at the transmitter and receiver sides. Phase noise causes two main detrimental effects: common phase error (CPE) and intercarrier interference (ICI). In this work, an iterative procedure is proposed where phase noise estimation (i.e., estimation of CPE and ICI) and data detection are performed interchangeably. The estimated phase noise parameters are assumed to be perfect when performing data detection and the detected data symbols are assumed to be correct when performing the phase noise estimation. To do this, we adopt the subspace-based pilot insertion scheme where pilot symbols are embedded in a subspace orthogonal to that of the data symbols. The conventional scheme that allocates a given number of subcarriers for pilot transmission can be viewed as a special case of the subspace-based approach, but this may not be the best choice of pilot and data subspaces. The efficacy of the proposed scheme is demonstrated through numerical simulations.