Abstract: According to the requirements for the real-time control in an adaptive OFDM system, a novel SNR blind estimation technique based on virtual carriers is proposed. By statistical processing of the virtual sub-carrier signal and the modulated sub-carrier signal, the average power of noise and that of signal plus noise can be achieved respectively and are further processed to achieve the SNR. The proposed technique is of low complexity. The technique outperforms the M₂M₄ blind estimation technique and is close to the pilot aided SNR estimation technique as the number of estimation samples increases. he result of simlation shows its validity.

Key words: OFDM, SNR, blind estimation