# Definition of MIMO (Multi-input Multi-output ),does this output mean antenna or transmitter?

I want to ask the definition of MIMO(Multi-input Multi-output )

If there are one transmitter and one receiver,each of them has $$N$$ antennas,$$N >1$$. So i can say it is a MIMO system.

But if now i have one transmitter with $$N$$ antennas,$$N >1$$.And $$5$$ receivers with single antennas for each,can this still be called MIMO?

I think it should be called MISO,because each receiver just has only one antenna.However,in this paper,it called this system "MIMO" system .

• If you look at the system as a whole, it's probably more accurate to call it MIMO. – BlackMath Jul 18 '19 at 6:57

Any communication system comprising of a transmitter with $$N >1$$ and receiver comprising of $$M>1$$ antennas is considered to be a MIMO system. So, this is not only limited to $$N=M$$ in the way you describe it.