Patent ID: 8180004

Claim:
A method for estimating an amount of distortion, comprising: receiving a transmitted signal to acquire a received signal; demodulating the received signal to acquire a demodulated signal; converting the demodulated signal into a digital signal; acquiring, as acquired data, (K+L) pieces of data from a portion corresponding to a pilot signal of the digital signal, where K is a number of samples included in one pilot signal symbol of the received signal, and L is DK with D being a predetermined integer value; and determining an estimated value of a carrier frequency offset based on a first Equation, where vector r 1 represents L pieces of data starting from a beginning of the acquired data, vector r 2 represents L pieces of data starting from (K+1)th data from the beginning of the acquired data, and the first Equation is: Δ ⁢ ⁢ f = f s 2 ⁢ π ⁢ ⁢ K ⁢ arg ⁢ { R p } , where Rp is a complex number derived from a second Equation, fs is a sampling frequency, and the second Equation is: R p = 1 L ⁢ r 1 H ⁢ r 2 - 1 L 2 ⁢ r 1 H ⁢ 11 T ⁢ r 2 , where vector 1 is an (L×1) vector with all elements being one, H denotes a Hermitian matrix, and T denotes a transpose matrix.