How to calculate RSRP of an SS Burst in the receiver?
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I would like to simulate an NR cell search scenario, where beam sweeping is used in a base station to transmit an SS Burst to the receiver. The receiver would, in turn, measure RSRP for each received beam to determine which of the beams would provide the best physical link.
I am using Matlab's 5G Toolbox and the openExample('5g/NRSynchronizationProceduresExample') as inspiration but I am uncertain where the RSRP calculation step should come in.
Per definition, “Reference signal received power (RSRP), is defined as the linear average over the power contributions (in [W]) of the resource elements that carry reference signals within the considered measurement frequency bandwidth.”
Considering the resource grid, where k is the index of the subcarrier fequency and l is the index of the OFDM symbol, a resource element, RE(k,l), carrying a PBCH-DMRS signal would contain a complex value inside, a(k,l).
After identifying the PBCH-DMRS sequence (and, therefore the SSB index), the receiver should know where the reference signals are located (in k and l), and, therefore, perform channel estimation. My guess would be that the RSRP could be calculated for each l=l_example as the RSRP(l_example)=abs(mean(a(k, l_example))). However that would give me l values of RSRP. So which value would be representative of the beam's RSRP?
Sriram Tadavarty on 5 Jan 2021
The RSRP measurement comes after the OFDM demodulation step. Just to note, channel estimation step is not performed to locate the reference signals.
For the scenario mentioned in problem statement, the close example from 5G Toobox is NR SSB Beam Sweeping.
This example is available from MATLAB R2020b.
You can also look after beam refinement using CSI-RS.