Patent ID: 7065027

Claim:
A method for locating an electric level distribution range of sampled signals, said electric level distribution range including a plurality of reference levels, said method comprising steps of: providing a plurality of initial values; corresponding each of said sampled signals to one of said plurality of initial values, which is closest thereto; and adjusting said initial values with said sampled signals respectively corresponding to said initial values according to a predetermined operation, thereby realizing said reference levels, wherein said predetermined operation is least mean square (LMS) operation performed by means of the following equations: ∂ ( z - lx ) 2 ∂ lx = - 2 ⁢ ( z - lx ) ( 1 ) lx′=lx +γ( z−lx ) (2) where lx′ is one of said reference levels, γ is an operation factor, z is an electric level of one of said sampled signals, and lx is one of said initial values, which is corresponded by said one of said sampled signals.