A complex channel model

Hello, everyone ! 
I have a complex channel model, do you know how to express the `HUI` by CVX ?


Expressions related to variable  are underlined in blue

variable:  q[n] = [x[n],y[n]] 

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where

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If the arguments of the trig functions are not constants (I’m assuming they are not), then the expression is neither convex nor concave,