Semi-blind Multiple Frequency Offset Estimation for Decode-and-Forward OFDM Cooperative Networks

• Main Authors: Ming-Yo Chen, 陳明佑
• Other Authors: Jia-Chin Lin
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/93508949959248174553

碩士 === 國立中央大學 === 通訊工程學系 === 101 === The cooperative networks recently become attractive because it can achieve spatial diversity. Multiple decode-and-forward (DF) relay nodes result in multiple carrier frequency offsets (CFOs) because each relay node owns its local oscillator. This paper presents a novel semi-blind multiple-CFO estimator for DF OFDM co-operative network. A procedure is designed for relay nodes in order to effectively derive the semi-blind multiple-CFO estimator. Each relay node occupies it own subchannels and its CFO falls in a nonoverlapped spectrum. The CFO mapping becomes simple to match their corresponding relay nodes. In addition, the proposed method can reduce hardware and computational complexity. Semi-blind random sequences are derived by the characteristic of signal matrix in MUSIC algorithm. Comprehensive simulations show that the random sequences can replace periodic training sequences. Furthermore, some information can be conveyed by the random sequences to increase the spectral efficiency.