Research in LTE Uplink Channel Estimation Techniques

• Main Authors: Yu, Juo-Han, 余卓翰
• Other Authors: Lin, David W
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/03886856729751496047

碩士 === 國立交通大學 === 電子研究所 === 100 === Wireless Communication will play an important role in the evolution of communication in the future, especially basing on WiMAX (IEEE) and LTE (3GPP) to develop individually. Although the two systems are very similar, the biggest difference of them is that LTE using SC-FDMA (single carrier frequency division multiple access) technique in uplink transmission. The advantage of LTE is to decrease peak-to-average power ratio (PAPR) which saves more power of the batteries of user equipments (UEs) and efficiently extends the using time, rather than using OFDMA (orthogonal frequency division multiple access) which is adopted by WiMAX. This thesis will introduce the subjects of channel estimation problems, algorithms, analysis of multi-path transmission in SC-FDMA. In channel estimation, first we use least square estimator, then use two different methods to estimate the channel response and compare the performance between them. The first method is polynomial interpolation. We use polynomial interpolation to interpolate the channel response of data carrier form reference signal channel response which estimates by least square estimator. The second method is using MMSE estimator. The same as method one, we get the channel response which estimates by least square estimator form reference signal, more than that we calculate the correlation between reference signals. By using the result, we use polynomial interpolation to interpolate the channel correlation of data carriers and reference signal carriers, then we substitute them into MMSE estimator to get the weighting of reference signal carriers to let channel response what we try to estimate be more accurate. In simulation, we test and verify the simulate model which we proposed, in AWGN. Then we simulate in multi-path channel. First we find that MMSE estimator has better performance than polynomial interpolation in SER and MSE; second we iv observe that if RS sequence use zadoff-chu sequence compare to the sequence which we supposed, the performance of channel response MSE is worse, but the performance of SER is better.