A Fine Frequency and Fine Sample Clock Estimation Technique for OFDM Systems

1 Background to the system This paper describes a low complexity method of calculating the estimate of fine frequency offset and fine sample clock offset in an OFDM receiver. Fine frequency offsets of less than one subcarrier spacing, and fine sample clock offsets cause loss of orthogonality in an OFDM receiver, leading to loss of noise margin. The described technique uses a short DFT to estimate frequency error. Since it does not require pilot carriers, it is efficient to implement, it is tolerant of multipath, relatively low in complexity and can achieve comparable performance to other schemes, according to software simulations. For typical multicarrier systems such as those mentioned above, The transmitted baseband signal can be written as s n N c e where N n N k N k j nk N