Performance Improvement of Semi-Blind Channel Estimation in MIMO-OFDM Systems

• Main Authors: Ju-Chin Yang, 楊如沁
• Other Authors: Der-Chang Tseng
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/u29f92

碩士 === 國立臺北科技大學 === 電腦與通訊研究所 === 100 === In this thesis we mainly study the performance improvement of semi-blind channel estimation in MIMO-OFDM systems under the slow Rayleigh fading channel. Generally, the performance of the pilot-aided channel estimation method is better than that of the semi-blind channel estimation method. However, the semi-blind channel estimation method can effectively save the transmission bandwidth due to not using the pilot symbols in transmission data. A new semi-blind channel estimation method is proposed in this thesis. First, the interference to the data signal is reduced by using the superimposed generalized chirp-like (GCL) sequence. Then we use the least square (LS) method to estimate the initial value of the channel frequency response. Based on the previous step, the correct channel frequency response is obtained by repeatedly doing the estimation and the detection steps, which can effectively reduce the effect of noise and increase the accuracy of channel estimation. Experimental results show that considerably improved performance can be achieved in terms of bit error rate (BER), compared with the conventional semi-blind channel estimation method.