Which coverage is higher 2T2R or 4T4R?

Hi Experts.

Which coverage is higher 2T2R or 4T4R?
And why?

Under same conditions.


4T4R, due to more samples at RX in Radio End & UE end.

Power also in 4 branches.


Coverage will be higher in 2T2R case as there will be high power per branch while in 4T4R coverage will be low as power is distributed among 4 TX branches.


For me coverage has no direct relation with the antenna configuration.

But due to impact on the user in some way, we consider this as coverage improvement scenario.

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Hi @Sivas_Viswa, can you please explain further your point?

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Hello, 4T4R has 3 dB gain from diversity, so that the coverage will not shrink compare with 2T2R.




Thank you! Nice piece of information with evidence :+1:

If I am using 40W RRU in 2T2R configuration than power per port will be 20W.

And if same 40W RRU is used 4T4R configuration than power per port becomes 10W.

So this coverage is reduced in 4T4R case. Isn’t it?

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Yes, that has been seen and verified in field as well.

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But you will gain from the diversity gain from 4T4R compared with 2T2R.

So after increasing you should improve as well the coverage not in terms of RRU power but in terms of diversity gain.

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Diversity gains is achieved.

Throughput is better.

But coverage hole increased.

Due to coverage reduction. As power per port reduces.

The diversity gain will not totally compensate the reduced RS power reduction.

Then may be you can boost the RS power by 1 or 2 dB.

See comaprison from this site:

Higher Order MIMO Impact in LTE TDD vs FDD[Practical result TDD 2x2 to 4x4 MIMO and FDD 4x4 to 2x2 change]

Yes throughput gets improved but at the same time coverage gets reduced.

Agree with @alaa_thabit : in the analysis, the MIMO order was considered as ‘locked’: 2 streams in DL and 1 in UL. eg: In LTE, a distant terminal will use TM3 diversity and a closer terminal will use TM3 Rank 2 (or even rank4). In Rank4, the energy will be by TX port. At TM3 diversity, the energy will be the sum of 4 TX ports, as all 4 ports will send the same data.

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I think coverage mostly has relation to the number of antennas and respective layers.

I could give more coverage with 2T but in 4T mostly work on beam forming or vice versa.

You get better coverage with 4T4R because of the increased diversity up/down.

People are making all kind of assumptions about supposed zero-sum output power and such. But that does not really relate to the question.

The simple matter is that increased diversity gives you increased coverage on uplink and downlink. End of story.


Could you please share this tool for calculation?

Thank you very much

Yoir thinking is correct, but it will depend on the vendor.
Some vendor has the output power defined by PA.
So the 2T2R model is 2x40W and the 4T4R is 4x40W.

In this case both solutions would have the same power.

I understand 4T4R have bigger coverage due to higher number of receivers.