Types of Beamforming in Wireless Communication

Pre-requisites: Spatial Filtering in Wireless Communications

In simpler terms beamforming is a procedure of sending electromagnetic signals in a particular direction rather than sending them in all directions by adjusting the phase and amplitude of the transmitted signals. Beamforming is formed by reinforcing the signal in a particular direction.

Why is Beamforming Required?

• It Increases the range of transmission and signal quality.
• It Efficiently uses power and reduces interference.
• Maximum data transfer possible.
• The amount of power consumed will be less than the power required in an Omnidirectional antenna.
• Good connectivity.
• Lesser call drops and data breaches.
• It provides diversity gain by coherent combining of the multiple signal paths.

Beamforming can be achieved by applying a precoding matrix that weighs the transmitted signals to form a beam in a particular direction.

Types of Beamforming

There are two types of beamforming

• Analog beamforming    
• Digital beamforming

Analog Beamforming: In analog beamforming, the phase and amplitude variation is applied to the analog signal to create a directional beam. This technique is used in older wireless communication systems and the signals from different antennas are summed up before the ADC conversion at the receiver’s end.

Digital Beamforming: In digital beamforming, the phase and amplitude variation is applied to the digital signal before Digital to analog conversion at the transmitter’s end to create a directional beam. This technique is used in modern wireless communication systems and is more flexible than analog beamforming.

There are two subtypes of digital beamforming:

• Precoding: The signal is preprocessed at the transmitter’s end to create a focused beam in the receiver’s direction.
• Post-Processing: The signal is received at the receiver and then processed to create a focused beam in the transmitter’s direction.

Applications of Beamforming 

• Wi-Fi Networks
• Cellular Networks
• Radar Systems
• Satellite Communication

Overall, beamforming is a powerful technique that can improve the performance of wireless communication systems in a variety of applications.

How Does Beamforming Implement?

• To implement beamforming, multiple antennas are arranged in an array and each antenna transmits the same signal but with a different phase.
• By adjusting the phase of each signal, signals can be combined and generate a stronger signal in the direction of the receiver.

Advantages of Beamforming

•  It Improves signal quality.
• The range of the signal Increases.
• Perform better in crowded environments

Disadvantages of Beamforming

• It can be effective only within a limited range.
• Its performance can be affected by environmental factors such as buildings, walls, rain, and other obstructions.
• Multiple antennas imply high hardware costs.

Comparison of Analog and Digital Beamforming in Wireless Communication

Features	Analog Beamforming	Digital Beamforming
Type of signal processing	Analog signal processing	Digital signal processing
Signal Processing Location	At the receiver’s end	At the transmitter’s end
Flexibility	Less flexible	More flexible
Hardware requirement	Fewer hardware requirements	Multiple hardware requirements
Interference	More interference	Less interference
System Complexity	Simple	Complex
Performance	Good for simple applications	Better for complex applications
Range	Limited range	Longer range
Applications	Used in older wireless communication systems	Used in modern wireless communication systems