MIMO Multipath for specific array geometry

Hello,

I am running a Direction of Arrival estimation algorithm - MUSIC - and i want to examine the effect multipath fading has on the estimation. I also want to do this for various array geometries, e.g. square, circular etc. I have seen the examples for comm.MIMOChannel but i cannot figure out how to specify directly or indirectly the array i am using. There is an argument 'NumReceiveAntennas' in the MIMOChannel constructor but how does one specify the configuration of these antennas? I am guessing multipath will have a different effect on a circular and on a linear array for example. What is the best way to do this?

Thank you for your time

Answer 1

[Honglei Chen]

comm.MIMOChannel does not specify the array geometry directly. Rather it uses correlation matrix to include the array effect. To do that, you can set the SpatialCorrelation to true and then specify the TransmitCorrelationMatrix and ReceiveCorrelationMatrix properties. See the reference page at

https://www.mathworks.com/help/comm/ref/comm.mimochannel-class.html

If you want to specify the array geometry directly, you can consider the scatteringchanmtx function or phased.ScatteringMIMOChannel depending on your preference. The function assumes a narrowband operation with isotropic elements. The latter allows specifying the array directly and provides more control on scatterer placements.

https://www.mathworks.com/help/phased/ref/scatteringchanmtx.html

https://www.mathworks.com/help/phased/ref/phased.scatteringmimochannel-class.html

HTH

[George Vardakis]

Thank you for your answer, it's been very helpful. One question regarding scatteringchanmtx. One argument is the txang, the transmission path angles. What is the reference direction of this i.e. if i have a transmitter at [5;5;0] meters at what direction is the path angle (0,0)? Is it at the direction of the x axis?

Thank you

[Honglei Chen]

Sorry I didn't see this earlier. The (0,0) is x axis.