How about CRLB method? Example:Estimating DC in WGN with unknown variance A pxA=了 四{z区钢-月 胫出效+4∑4w-+∑n- 6A {(-)∑m-NA+a∑)+} =} It is hard to factorize into I(A)(g(x)-A) CRLB method does not apply whxiong@uestc.edu.cn 6whxiong@uestc.edu.cn 6 It is hard to factorize into I(A)(g(x)-A) = 1 A ½µ 1 ¡ 1 A ¶Xx[n] ¡ NA + 1 2A Xx 2 (n) + N 2 ¾ How about CRLB method? @ ln p(x; A) @A = ¡ N 2A + 1 A X(x[n] ¡ A) + 1 2A2 X(x[n] ¡ A) 2 CRLB method does not apply p(x; A) = 1 (2¼A) N=2 exp ½ ¡ 1 2A ³Xx[n] ¡ A ´2 ¾ Example: Estimating DC in WGN with unknown variance A