PSS and SSS are transmitted in central six RB's. As it takes RE's from 6 RB's only, so this can work for all system bandwidths from 1.4 Mhz to 20 Mhz. PSS and SSS are mapped to the central 62 sub carriers. Although in LTE, 72 subcarriers (6 RB) are available, only 62 are used so that UE can perform the cell search using an efficient length of 64 FFT.
