virtual mimo
Could you please give me some imformation on Virtual MIMO that I can learn what it is. give me a link or anything about virtual MIMO.
Is it good to do a project or reserch on it. is it important in the coming future?
Please help if there is anyone know about it. Thank you again.
MIMO;
Multiple input Multiple output.
Search in this forum is is full of papers and books.
No,
What I want to know is Virtual MIMO not MIMO. I know MIMO but i dont know exactly what virtual MIMO is
virtual mimo
also could call it "distributed mimo" or "distributed antenna array",it is distributed system.
conventional mimo is a kind of communication system with multiple antennas in one terminal,while virtual mimo is one antenna in one terminal,the one share the others's antennas ,so called it virtual mimo.
i've been in a project of virtual mimo with ofdm
Virtual Antenna Array is the process of grouping multiple communication terminals into one (at least virtually one). All this communication terminals contribute their antennas to form the Virtual Antenna Array. When you have a Virtual Antenna Array on both ends of the communication, then you have a Virtual MIMO.
It DOES play a significant role in wireless communications given that regular MIMO is not always possible.
It is an excellent research topic, rapidly developing and my personal opinion is that is going to be the foundation of the 5th generation mobile telephony (5G).
(Keep in mind that for a typical MIMO system, the general rule -rule of thumb- is to keep at least half wavelength of distance between two antenna elements installed within a wireless communication terminal).
For a typical 3G system, the half wavelength is almost 7.5cm. In other words you cannot have antenna elements in distance shorter than 7.5cm. Hence, you can fit no more than 2 antennas per mobile communication terminal. Although, two antennas is a good start for MIMO, we have to admit that it is not providing the solutions we are looking for.
Virtual MIMO enables you to make use of all the neighbour communication terminals (depending on the protocols you are using) and hence the size of MIMO channel increases significantly (assuming that we are talking about urban areas). By increasing the size of the MIMO channel you increase Degrees of Freedom and consequently you achieve spatial diversity gain!
Also, when you select a suitable interference cancellation scheme (Bank of Matched Filters, Maximum Likelihood etc) you can achieve excellent BER and Capacity performance.
Limitations are:
1. The more the users on your system the larger the computational complexity necessary to process (sometimes exponentially increased with the number of users).
2. By keeping the number of users small you need to develop a decision protocol which users and under which criteria will you select.
3. When you are trying to make use of your neighbour mobile communication terminal but the particular mobile device is occupied or unavailable, how will you deal with this problem?
We know in MIMO arrays of antenna are equipped at transmitter and receiver side, but when size of transmitter/receiver is very small then implementing this become impractical hence we use single antenna at transmitter/receiver & between them no. of single antenna equipped terminals are placed to create a virtual mimo, thats called as Virtual MIMO.