Massive MIMO
Hello Readers!!!
I’m back with another new and interesting topic called Massive MIMO
I believe that most of us have heard the term “MIMO(Multiple Input Multiple Output)” but not sure what does it mean. So, here I will be explaining what is MIMO and will dug little deep into the concept of Massive MIMO
What is MIMO?
MIMO is a radio link technology which deploys multiple antennas in both transmitter and receiver side to increase the throughput, capacity and quality of a radio link. The initial variant of MIMO includes 2 antennas in both transmitter and receiver side i.e 2x2 but later to increase the use of simultaneous data streams in wireless technology enables the current 4G LTE network to use 4x4 MIMO. MIMO works with the help of 3 techniques spatial diversity, spatial multiplexing and beamforming.
What is Massive MIMO?
Now as we live in 5G world and to meet its demanding requirements, operators using many key technologies to increase the performance and one of such key technology is massive MIMO.
In simple words Massive MIMO is the extension of MIMO. It has more number of antennas placed in both transmitter and receiver side. This Massive number of antennas helps to improve the throughput and efficiency. Massive MIMO can have infinite number of antennas but practically now we are using 32x32, 64x64 which can be expanded to 128 and more in future.
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Now we will think, how such number of antennas are placed in base station, right?🤔 Simple answer, with 5G NR massive MIMO, antennas sizes are reduced, so we will have smaller sizes of antennas placed.
This massive MIMO concept is based on the below 3 key techniques
- Spatial Diversity
The signal emitted from transmitter antennas will undergo reflection from buildings and other obstacles which result in multiple paths. These reflected signals will be received by the multiple receiving antennas with different time delays, level of attenuation and path. such different version of signals at receiving side can be combined mathematically to improve the quality of the signal. This technique is known as spatial diversity since the receiver antennas are spatially separated from each other.
2. Spatial Multiplexing
Spatial multiplexing increases the capacity of the radio link. As per the term “Multiplexing”, here multiple unique data streams are sent between transmitter and receiver. Imagine that the data between base station and mobile is sent via a pipeline. So now if we have one antenna in both transmitter and receiver side then single data can be sent one by one. But with multiple antennas are added in both transmitter and receiver side, multiple virtual pipelines can be created over the air and will carry multiple unique streams of data. It will create multiple path for more data to travel between transmitter and receiver and thus increases the capacity of the radio link.
3. Beamforming
Beamforming is another key technique of massive MIMO, which uses advanced antenna technologies to focus a wireless signal in a specific direction, rather than broadcasting to a wide area.
Consider a tube light and a night lamp as an example. You want light only in a specific part of the room and if you use tube light(large in size) it will spread the light to the whole room but if you use night lamps or other smaller lamps (smaller in size compared to tube light), it will give light only to that specific part of the room. Likewise, with the use of multiple smaller antennas, wireless signals can be transmitted to the one specific direction.
With this massive number of antennas in massive MIMO enables 3D beamforming, which creates both horizontal and vertical beams toward users, increasing data rates and capacity for all user, particularly useful in urban areas with high-rise buildings.
Thanks for reading till end. I hope, you got some good information from this story. Will be back with another interesting topic.
Happy Reading !!! 😊
