5G NR Massive MIMO, Beamforming using single-panel antenna and Total Array Directivity Gain

Here I try to depict the concept of the following items:

  • Antenna Element (AE)
  • Subarray
  • Array of subarrays
  • Single-Panel Antenna which is made by array of subarrays

Finally I will show how total array directivity gain is calculated.

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Hi Rahim, I have a doubt regarding the number of antenna elements used in an antenna & Antenna naming, xTxR.
from the below table, we can observe that there 4 types of xTxR antennae with different panel number & polarization number. I want to know how we are choosing the required TRx


These are different antenna types.

Each setup has its advantages and disadvantages. In general:

  1. The more antenna elements you have (total AE) the higher is your antenna array gain thus coverage. But also your antenna is bigger.

  2. The more xTxR you have, the greater is your MU-MIMO capability (cell capacity) as you can potentially schedule more users into same resources etc. But also your active antenna is more complex and expensive.

  3. The size and number of your subarrays determine your “scanning” range ie into what directions your active antenna can transmit without significant gain loss. Trade off between dense urban city center and suburban town where you don’t need big (vertical) scanning range with more costly antenna.

So if you look at your table, in first row you have a 1 vertical column with 4 horizontal columns and 8T8R. This is a classic passive antenna with external radio that can do only horizontal beamforming.

Fourth row is common MaMIMO antenna in a small factor size, good trade off between Urban/Suburban.

It can do beamforming in both vertical and horizontal directions.


Thanks for your clarification