Enhancement of Channel Estimation for MIMO-OFDMA Systems Using Iterative Interpolation and Improved Path-Detection Method

• Main Authors: Chang-Yang Wu, 吳昌暘
• Other Authors: 曾德樟
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/q5m8e6

碩士 === 國立臺北科技大學 === 電腦與通訊研究所 === 102 === In this thesis, we mainly study the performance improvement of channel estimation in MIMO-OFDMA systems. In order to improve the quality of the channel estimation of the comb type arrangement, we firstly use the least square (LS) algorithm to estimate the channel frequency response of pilots. Secondly, we use the iterative interpolation method (IIM) to interpolate the channel frequency response of data signals. Then, the channel impulse response is obtained by using the inverse fast Fourier transform (IFFT). To find the frequency response of the actual channel, we utilize the improved path detection (PD) method to estimate the accurate channel path. One threshold was set to separate the channel impulse response and noise in this PD method. If the magnitude of the channel impulse response is greater than the threshold, the corresponding channel can be regarded as main channel path. The others are regarded as noise and are set to zero to improve the accuracy of estimation, enabling the estimated results to close to the actual channel frequency response. Experimental results show that the proposed scheme obtains the best performance in terms of the bit error rate (BER) among the IIM scheme combined with the different methods, such as, the traditional LS, FFT-based, Hayashi, PD, and the least mean square (LMS) estimation methods.