MIMO notation

[stuartdm]

Hi guys,

I would like to know more about the tx x rx : streams notation. As I understand 3x3 : 2, for example, means that 3 antenna are available to transmit/receive at any one time and that 2 different pieces of information can be simultaneously transmitted/received using those 3 antenna.

Is this correct or is there more going on?

Thanks

[primoz_marinsek]

Yes, that is correct. The T x R : S notation stands for that.

Transmit x Receive:Spatia_Streams

What was your motivation for asking this? I'm guessing there is more to it than that?

[stuartdm]

Hi Primož,

Thanks for your reply. The reason I ask is that I am preparing for a ruckus exam and I want to make sure I understand the basics of how the hardware works.

Also because I was curious :).

[primoz_marinsek]

Sure. Ask what you like and we'll answer. We wouldn't want you to fail your exam 🙂

[jeffrey_darst]

I'd like to understand more how spatial streams are defined. If there are 3 transmitters and 3 receivers the AP can send three spatial streams but since WiFi is only half duplex, will it send three streams to one device or one stream to three devices ? I believe an iPhone 5 is a single stream device, some laptops support two streams.

For SU MIMO I assume its three streams to ONE device. Not until .ac is out that supports MU MIMO will the device send to three devices.

This is what I'm looking for clarification on.

thanks