LTE: Why PSS and SSS are transmitted on the last and second last OFDM symbols of slot zero ?

Question

I know that fact PSS and SSS are transmitted at slot zero of first and fifth sub frames of a radio frame. But what is the reasoning behind it to transmit at these particular location ? Is any calculation behind it ?

Answer 1

Because To know the Slot boundary. From PSS, UE know that PSS transmit at last symbol of subframe. So now it knows the slot boundary. And now UE also knows that, last but one symbol is SSS, now it decode SSS and came to know the CP value. From CP, it comes to know, is it extended CP or normal CP in the subframe.

As we already know the timing of each subframe is 1ms, so it calculates slot, frame, sub frame locations and decode other physical channels info to get synchronisation with network.