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 |