On Decoding and Equalization of OFDM Systems

• Main Authors: Pei-Chun Liu, 劉姵君
• Other Authors: Kwang-Cheng Chen
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/46271931905334191346

碩士 === 國立臺灣大學 === 電信工程學研究所 === 89 === In the thesis, we develop an effective method (MC-PDFD) to combat the residual ISI (intersymbol interference) effect in OFDM systems employing multi-dimensional trellis-coded modulation (TCM) schemes. The proposed method combines the tasks of trellis decoding and equalization altogether and removes the residual ISI simultaneously in the decoding process. The complexity and robustness of MC-PDFD are also discussed. Simulation results show that MC-PDFD works well in different channel conditions with perfect channel information and degrades slightly with non-perfect channel information. Furthermore, we examine the effects on peak-to-average (PAP) ratio when multi-dimensional TCM schemes are applied to OFDM systems. As a comparison, PAP ratios with 2-dimensional trellis-coded OFDM systems are also included. The result shows that using multi-dimensional TCM with OFDM systems reduces the PAP ratio and is thus considered a good candidate of coding scheme in OFDM communication systems.