Higher Subcarrier Spacing impact on Throughput

Hi Experts,
In 5G, can higher subcarrier spacing have impact on throughput?
Will there be positive impact on latency with it?

I think it could have a positive impact.
ACKs are faster with a higher numerology whereas with a lower numerology will be slower.
Otherwise what is gained in time with a higher numerology it is lost in number of PRBs: you halven the time but you also halven the number of PRBs.

So higher ACKs leads to faster LA and MCS changes. Which will give higher throughput?

I don’t think its is such a major change in throughput.
It is faster ack’s so harq processes are pooled faster.

So throughput will have no impact?

Throughput performance will be better in high mobility cases if we have high SCS.
Specially in case of bullet trains.
For high mobility users low SCS cannot help with Doppler shifts, which can be taken care by high SCS.

This is true for high speed cells otherwise I don’t think we could notice a difference otherwise nobody would use low numerology.

Yes basically high SCS is allotted for high bandwidth which inturn have high throughput by default.

  • Requirements for SCS vary with service types, frequency bands, and moving speeds.
    – URLLC service (short latency): large SCS
    – Low frequency band (wide coverage): small SCS
    – High frequency band (large bandwidth, phase noise): large SCS
    – Ultra high speed mobility: large SCS

  • Impact of SCS on coverage, latency, mobility, and phase noise
    – Coverage: The smaller the SCS, the longer the symbol length/CP, and the better the coverage.
    – Mobility: The larger the SCS, the smaller the impact of Doppler shift, and the better the performance.
    – Latency: The larger the SCS, the shorter the symbol length/latency.
    – Phase noise: The larger the SCS, the smaller the impact of phase noise, and the better the performance.

In OFDM, number of subcarrier that can be packed into a specific frequency range is directly related to spectrum efficiency (how many bits can be transmitted per Hz per second).
The more subcarriers you can pack into a frequency range (i.e, the narrow subcarrier spacing you use), the more data you can transmit (or receive).

But in throughput there is no impact, do You agree?

If we use the same bandwidth with SCS 120 and SCS 240, don’t you think SCS 240 will have better throughput?

Why would that happen?
You will have half of RBs in SCS 240 compared to SCS 120, right?
It will be faster ACKs, so pooling of 16 HARQ processes will happen faster.
Very difficult to say what would happen to throughput if SCS is increased.

Yes, never saw in the real network this testing, but for sure if the user is high mobility case, then 240 SCS will be performing better.

I would have to agree, except for high mobility use cases.

Research paper on increaisng scs upto 3840khz in Terahz band for beyond 5G/6G.

5G New Radio Evolution Towards Sub-THz Communications