How do we define the lookup table for '5G NR CQI Reporting'?

Hello,

I am trying to test '5G NR CQI Reporting' with different channels, such as CDL-B and CDL-A, however, I need to modify the CQI lookup table for a range of SNR so my question is how can I compute the lookup table needed for channels CDL-A and CDL-B?

Many thanks,

Waseem

Answer 1

[Sriram Tadavarty]

Hi Waseem,

The BLER versus SINR result is placed by running the simulations in NewRadioPDSCHThroughputExample. The PDSCH throughput example is updated to configure a CSI resource definition, as defined in TS 38.214 Section 5.2.2.5. The simulation is performed for 100 frames, with the step size of 0.5 dB and TS 38.214 Table 5.2.2.1-2 as cqi-table. The simulations consider the practical channel estimation method, with 'AveragingWindow' as [5 1], for a SISO scenario. 'AveragingWindow' specifies the number of adjacent reference symbols in the frequency domain and time domain, over which averaging must be performed in the channel estimation procedure. Simulations for PDSCH throughput are performed by considering the modulation scheme and code rate corresponding to each CQI in cqi-table, considering certain channel conditions and across a finite range of SINR values with zero interference. The SINR value observed at the receiver, where the target BLER (0.1) is achieved, gets mapped against each CQI index.

So, for your case, update the channel model used in throughput example to CDL-A or CDL-B, and then include a CSI-RS resource definition as in TS 38.214 Section 5.2.2.5. Capture the SNR values at which BLER is 0.1. As, the throughput example doesn't consider any interference, SINR and SNR is the same.

Hope this helps.

Regards,

Sriram

[Faisal M]

Thanks Sriram

Many thanks for your comments. I'm wondering about the followings:

1- The example shows the throughput in % without the BLER. Does it mean that SINR with 0.9 throughput should be captured?

2- how the example NewRadioPDSCHThroughputExample can be updated and configure for a specific channel model. I couldn't link TS 38.214 Section 5.2.2.5 with specific part in the example.

Thanks,

Faisal