“…LS estimation algorithm is a general algorithm with simple structure and low computational complexity. In addition, channel estimation methods include blind channel estimation and semi-blind estimation [4,5,7] and try to avoid the use of training sequence, thus the information transmission rate is improved effectively, but the blind estimation that based on higher-order statistics takes a long time to observe the data, not only the high computational complexity that go against the real-time estimate, but it is unrealistic to assume that the channel keeps constant in a long data segment. Estimation error will affect the performance of the system no matter what algorithm applied to channel estimation [3,4,8,9] .…”