A receiver and method of detecting a guard interval estimate accurately by performing an Nth order polynomial based non-linear quantization on a pre-estimated guard interval in a received Orthogonal Frequency Division Multiplexing (OFDM) signal in a receiver is provided. The pre-estimated guard interval is obtained by performing normalized auto-correlation on the received OFDM signal. The method includes (i) performing a rounding operation on (a) one or more mth coefficient of the polynomial and (b) the pre-estimated guard interval to obtain an indexing parameter ‘k’, and detecting the guard interval estimate based on (i) a value of k, and (ii) a guard interval from one or more guard intervals that are stored in a look up table. The guard interval estimate is detected in accordance with an equation: {tilde over (L)}=L[k−4], where ‘L’ is the guard interval stored in the look up table that corresponds to the value of k.