说明：  半盲估计算法利用很少的导频符号，以LMMSE准则来估计、初始化信道系数，运用的两种算法进行对比，牺牲极小的带宽而尽可能准确的传输有用信息
(Half blind algorithm using little pilot.finally symbols, with LMMSE criteria to estimate, initialization, the use of the channel coefficient two algorithm is compared, and sacrifice of tiny bandwidth and accurately as possible transmission useful information )