I/Q mismatch compensation in an OFDM receiver in presence of frequency offset

A receiver for an orthogonal frequency division multiplex radio signal in which a carrier frequency is modulated by sub-carrier signals (SI) coded with data, the receiver comprising analogue signal processing means for combining a received radio frequency signal with at least one reference frequency signal and producing analogue signals (I-Rx, Q-Rx) in phase quadrature whose frequencies are functions of frequency differences between said radio frequency signal and said reference frequency signal, analogue-to-digital converter means for converting said analogue signals to phase quadrature digital signals (xI(n), xQ(n)), and digital signal processing means including demodulator means for reproducing said sub-carrier signals, mismatch compensation means for combining each of said reproduced sub-carrier signals (RI) according to a mismatch coefficient (A(k)) with another of said reproduced sub-carrier signals (R−I) whose sub-carrier frequency is symmetrical therewith and compensating for offset (Δfc) of said reference frequency relative to said carrier frequency, and decoding means for recovering data from the reproduced and compensated sub-carrier signals,

• characterised in that said compensation means is arranged to combine each of said reproduced sub-carrier signals (RI) with a plurality of said reproduced sub-carrier signals (R−I, Rk) according to respective values of said mismatch coefficient (A(k)) and according to a respective frequency offset coefficient (λI, k) that is a function of an estimated value of said offset (Δfc) of said reference frequency relative to said carrier frequency.