Dual Polarized Antennas Can be used for 2X2 MIMO?

[khurrambilal01]

Hi friends,

Can we use Dual Polarized antennas as MIMO antennas as well?
The same single dual polarized antenna can be 2X2 MIMO?
Please elaborate or if you can share any document!

Thanks!

[dimooon11]

Antenna is a passive element so you can use any dual polarized anenna with two ports to achive MIMO 2x2.
Antenna should has good isolation between ports at least 25-30dB so transmission of signals via +45 and -45 ports will ensure necessary de-corellation of signals for spatial multiplexing.

[wolverine]

You can yes. I don't have any documents but we have performed a MIMO trial using the existing cross polarised antennas and it worked fine.

[mobile4lte]

Using aperture coupling technology and dual feed technology to design a high gain, high isolation, double polarized H type aperture coupling antenna unit, on the basis of the design of multiple antenna systems. Through the analysis of the different array yuan spacing for MIMO base station antenna more than the influence of mutual coupling, and determines the best array yuan spacing, tested here in frequency from 2.14 GHz place far field pattern, the measured horizontal polarization port place maximum gain 14.89 dB, vertical polarization port place maximum gain 14.78 dB, and the simulation results are in good agreement.

[khurrambilal01]

Using aperture coupling technology and dual feed technology to design a high gain, high isolation, double polarized H type aperture coupling antenna unit, on the basis of the design of multiple antenna systems. Through the analysis of the different array yuan spacing for MIMO base station antenna more than the influence of mutual coupling, and determines the best array yuan spacing, tested here in frequency from 2.14 GHz place far field pattern, the measured horizontal polarization port place maximum gain 14.89 dB, vertical polarization port place maximum gain 14.78 dB, and the simulation results are in good agreement.

Can you share some document for this or reference?
Thanks!

[elkador]

All operators deploying LTE with 2X2 MIMO are using cross-pol antennas to provide diversity at the eNodeB.
Mainly because of space contraints and related cost of installation.

However results have shown that Polarization was an excellent way of providing MIMO in Dense Urban & Urban areas. In Rural areas, space & polarization diversity might be used at the same time to give you some extra-gain.

[eino]

Dear All,

what about deploying it in WCDMA network and how we are going to compensate the absence of RX diversity.

if anyone have any document,please share it

[dimooon11]

Dear All,

what about deploying it in WCDMA network and how we are going to compensate the absence of RX diversity.

if anyone have any document,please share it

I can't tell you anything regarding WCDMA but MIMO doesn't cancel rx diversity.
There will be rx diversity at BS side but you need also 2 rx paths in subscriber equipment.

[khurrambilal01]

2X2 MIMO includes two TX diversity paths and two Receive diversity paths. Receive diversity has no gain while using 2X2 MIMO but transmit has gain.2X2 MIMO doesn't impact recieve diversity but 4X4 MIMO enhances the receive paths as well.
The UE/MS needs to have two antennas as well to support 2X2 MIMO transmit diversity.

For your information no Mobile UE/MS currently supports MIMO, Only a few USB/Dongles are having MIMO supportability.


Dear All,

what about deploying it in WCDMA network and how we are going to compensate the absence of RX diversity.

if anyone have any document,please share it

[dimooon11]

Receive diversity has no gain while using 2X2 MIMO

Excuse me but I disagree with you.
In the receive direction, the BS coherently combines signals received from different receive paths using the maximal ratio combining (MRC) technique. MRC provides second order diversity in case of two-receive path configuration.
At this point it is worth toremember that MIMO can provide two types of diversity:
1) STC/SFBC/ - to compensate fadind and improve CINR
2) Spatial Multiplexing (SM) - to double throughput
In our case it is not MIMO, because User Equipment don't have 2TX, it is SIMO but receive diversity (not SM) still exist as receiver obtains multiple copies of signal.

[ali marhoon]

thanks for your shared information..

[khurrambilal01]

Excuse me but I disagree with you.
In the receive direction, the BS coherently combines signals received from different receive paths using the maximal ratio combining (MRC) technique. MRC provides second order diversity in case of two-receive path configuration.
At this point it is worth toremember that MIMO can provide two types of diversity:
1) STC/SFBC/ - to compensate fadind and improve CINR
2) Spatial Multiplexing (SM) - to double throughput
In our case it is not MIMO, because User Equipment don't have 2TX, it is SIMO but receive diversity (not SM) still exist as receiver obtains multiple copies of signal.

I am comparing the Rx Diversity performacne of Non-MIMO system with MIMO system and in both cases if MIMO doesn't has spatial diversity (Dual Polarized antennas) then Rx-path is similar and no gain is achieved over Non-MIMO system because non-MIMO system also uses the two Rx-paths to combine them.

[dimooon11]

True! Even if MIMO would have spatial diversity then there is no additional gain to existing RX gain (2x2 MIMO).