Patent ID: 8873681

Claim:
A process for canceling Intercarrier Interference in a OFDM receiver comprising digital signal processing circuits, said OFDM receiver receiving OFDM blocks in presence of Doppler, said process comprising the steps of: receiving a OFDM block, said OFDM block comprising N samples; applying, by said digital signal processing circuits, a Fast Fourier Transform (FFT) on said OFDM block for the purpose of generating N frequency domain representations composing the received signal; multiplying said received signal by the hermitian value of the channel by said digital signal processing circuits, with H being the channel estimate; and applying on said received signal a preconditioned conjugate gradient algorithm based on a N×N P preconditioner matrix by said digital signal processing circuits; wherein said preconditioning matrix is computed as follows: f n T =1 n H S n T [S n H ( H +σ z 2 I ) S n T ] −1 And P = G ˘ = [ f 0 T ⁢ S 0 f 1 T ⁢ S 1 ⋮ f N - 1 T ⁢ S N - 1 ] Where S n is a L FIR ×PN selection matrix obtained by extracting a predetermined number (L FIR ) of rows from the identity matrix I PN ; LFIR being a predetermined integer inferior to PN, with p corresponding to the basis expansion order chosen and N is the FFT size; is equal to HF H , with H being the frequency-domain channel matrix and F being the N×N discrete-Fourier transform unitary matrix F; I is the N×N identity matrix; σ is the varience of the noise; and 1 n is being the 1×N vector containing 1 in n-th position and 0 elsewhere.