# Possibility of using Power allocation with Maximum likelihood estimation

I have a basic question about maximum likelihood (ML) estimator and its implementation with power allocation.

Suppose we are using $$MIMO$$ system with $$4$$x$$4$$ transmit and receive antennas, so the received signal which includes the signal + noise + ISI can be written :

$$y = HX + n$$

$$H,X, n$$ are the channel, transmitted signal and noise, respectively. suppose that only first antennas is active and other antennas are not active, so the transmitted signal will be as below:

My question is about the possibility to use power allocation to detect the active antenna, which means the estimated signal will be as:

I am asking if we can detect the active antenna in that way, is that possible ? Is there another method we can use instead of that ? Is there any document explain that ?

Thank you.

• Have a look into spatial modulation. – BlackMath Apr 12 '19 at 11:50
• @BlackMath Yes it's the same of Spatial modulation, but I think even if using this algorithm with SM, it can't be used. (as mentioned in below answer) – New_student Apr 12 '19 at 12:00