Why SS

Maybe due to the PSS is transmitted sometimes with an unknow “offset” power, and the UE is not provided with this “offset”, so the UE must deduce the value of the transmit power offset.

The idea was extracted from: “5G New Radio IN BULLETS”, from Chns Johnson, Section: DOWNLINK POWER CONTROL (Page 457)

“The Primary Synchronisation Signal (PSS) may be transmitted using an EPRE which is equal to the SSS EPRE, or it may be transmitted with an EPRE which is 3 dB greater than the SSS EPRE. There is scope to increase the transmit power of the PSS becausethere are unused Resource Elements both above and below the PSS (within the set of20 Resource Blocks used by an SS/PBCH Block). Increasing the EPRE by 3 dB means that the total power within each symbol of an SS/PBCH Block remains approximately constant. The UE is not provided with information regarding the transmit power of the PSS so the UE must deduce the value of the transmit power offset. Having knowledge of the offset is useful for UE which are capable of Interference Cancellation ( IC). Knowledge of the offset simplifies the generation of the signal to be subtracted from the wanted signal. In addition, having knowledge of the offset is useful for the VE receiver Automatic Gain Control (AGC) which can be tuned according to the power or each symbol belonging to the SS/PBCH Block”