Beamforming and Beam Management

- Why We Need Beam?

The idea of beamforming is to steer the beam to only the desired direction or user. Since energy is not spread in all directions, the transmission range is thus improved by concentrating the beam in one direction.

Beamforming uses the science of electromagnetic interference to make Wi-Fi and 5G connections more precise. Beamforming is a technique that focuses a wireless signal towards a specific receiving device, rather than having the signal spread in all directions from a broadcast antenna, as it normally would. The resulting more direct connection is faster and more reliable than it would be without beamforming. 

Although the principles of beamforming have been known since the 1940s, in recent years beamforming technologies have introduced incremental improvements in Wi-Fi networking. Today, beamforming is crucial to the 5G networks that are just beginning to roll out.

It’s a very exciting time for the wireless industry. Currently, much of the industry 5G focus is on enhanced mobile broad band, driving toward higher and higher network capacity and throughput utilizing beamforming techniques in mid-band and high-band spectrum. Mostly by Nature of the wave (by Physics), when we use low and mid range of frequency, we can transmit a signal in all direction or relatively wide angles. However, when we use very high frequency, we would not have much choice except using a huge antenna array. As a result of using this kind of huge antenna array, the resulting radiation would be a beam. 

- Beamforming Technology

Beamforming is the ability to adapt the radiation pattern of the antenna array to a particular scenario. It is a technique by which an array of antennas can be steered to transmit radio signals in a specific direction. Rather than simply broadcasting energy/signals in all directions, the antenna arrays that use beamforming, determine the direction of interest and send/receive a stronger beam of signals in that specific direction. 

Due to the high propagation loss of the millimeter wavelengths (mmWaves) employed in 5G new radio (5G NR) systems, plus the high bandwidth demands of users, beamforming techniques and massive Multiple Input and Multiple Output (MIMO) are critical for increasing spectral efficiencies and providing cost-effective, reliable coverage.

Beamforming technique is widely used in radars and sonar, biomedical, and particularly in communications (telecom, Wi-Fi), specially 5G - Where very high data rates are required and the only way to support this would be to maximize transmit and receive efficiency by using beamforming. In this technique, each antenna element is fed separately with the signal to be transmitted. The phase and amplitude of each signal is then added constructively and destructively in such a way that they concentrate the energy into a narrow beam or lobe. 

- 5G Beamforming

5G uses radio frequencies between 30 and 300 GHz, which can transmit data much more quickly but are also much more prone to interference and encounter more difficulty passing through physical objects. As the number of mobile users and their demand for data rises, 5G must handle far more traffic at much higher speeds than the base stations that make up 4G/LTE’s cellular networks. Beamforming is one of the burgeoning technologies that will help get us there.

When we send or receive informative signals carried over a 5G mobile network, where its expected operating frequency is much higher than that of a traditional mobile system, we inevitably suffer from significant electromagnetic wave attenuation, causing signal integrity issues. In order to make the electromagnetic wave travel a longer distance with the limited amount of power in a communication system, it is necessary to deploy a high-gain antenna that shapes the far-field radiation pattern like a very sharp, pencil-like beam. This enables us to reach longer distances for delivering uninterrupted information. 

Beamforming is a traffic-signaling system for cellular base stations that identifies the most efficient data-delivery route to a particular user, and it reduces interference for nearby users in the process. Depending on the situation and the technology, there are several ways to implement it in 5G networks. 

- Beam Management for 5G

Millimeter wave (mmWave) communications with massive antenna array is key technique for the future cellular systems. While large arrays enable high gain, directionality and user multiplexing, practical realizations face challenges in radio hardware design and cross layer processing.

Massive MIMO is one of the promising techniques to improve spectral efficiency and network performance for reaching its targeted multi-gigabit throughput in 5G systems. For 5G New Radio (NR) systems, one of the key differences compared to 4G systems is the utilization of high frequency millimeter wave (mmWave) bands in addition to sub-6GHz bands. 

To keep the complexity and implementation cost low, hybrid analog-digital beam-forming with large-scale antenna array has become a common design approach to address the issue of higher propagation loss as well as to improve spectral efficiency in mmWave communication in 5G NR. The 5G NR standard is designed to adapt to different beam-forming architecture and deployment scenarios.

The objective is to utilize the limited radio-frequency spectrum resources and radio network infrastructure as efficiently as possible.