How exactly UE calculate RSRP?

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1

Hello Experts.

How exactly UE calculates RSRP?

At what point it is being calculated im the receiver chain?

2

RSRP is calculated as the ratio of the total power of the received signal to the total number of resource elements used for the measurement. The formula for RSRP in decibels relative to milliwatts (dBm) is typically: RSRP (dBm) = 10 * log10(P_signal / N_RE)

  • P_signal: Total power of the received signal within the measured resource elements.
  • N_RE: Total number of resource elements used for the measurement.

As for when RSRP is calculated in the receiver chain of the UE, it occurs after the initial reception and mapping of the physical signals from the cell tower onto resource elements. The UE continuously measures RSRP to monitor the signal strength of the serving cell and neighboring cells. This information helps the UE make decisions about which cell to connect to and when to initiate handovers, ensuring a seamless and optimal network experience for the user. The exact implementation details may vary between different UE chipsets and network equipment vendors, but the fundamental principles of RSRP measurement remain consistent.

3

just to add,to the explanation, the reference point for the SS-RSRP shall be the antenna connector of the UE. More details in TS 38.215.

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4

Hi, my confusion was not on the calculation of SS-RSRP. Let me state it again: SS-RSRP is calculated based on the SSS received power. It is the average power of the SSS Resource Element. Also, the spec says that the reference point for this power is the antenna connected to the UE. How exactly the antenna power is mapped to the RE power? Since the SSS position and SSS RE level information is only available after down-conversion, ADC, OFDM demodulation, CP removal & resource mapping at the receiver. Is it like we calculate the SSS average RE power and then account for all the power conversions we have done from antenna reception to resource mapper?

5

Yes, that is correct. To calculate SS-RSRP, you need to account for all the power conversions that have been done from antenna reception to resource mapper. This includes the gain of the antenna, the loss in the transmission line, and the gain of the receiver.

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