Basic principle of beamforming

Beamforming comes from the concept of adaptive antenna. The signal processing at the receiving end can form a desired ideal signal by weighting and synthesizing the signals received by multiple antenna elements. From the perspective of antenna pattern, this is equivalent to forming a beam in a specified direction. For example, the original omni-directional reception mode is converted into a lobe mode with a zero point and a maximum direction. The same principle applies to the sender. By adjusting the amplitude and phase of the antenna unit feed, the required mode can be formed.

If beamforming technology is to be adopted, the premise is that multi-antenna system must be adopted. For example, Multiple Input Multiple Output (MIMO) not only uses multiple receiving antennas, but also uses multiple transmitting antennas. Since multiple groups of antennas are used, wireless signals from the transmitter to the receiver correspond to the same spatial stream and are transmitted through multiple paths. Using a certain algorithm to process the signals received by multiple antennas can obviously improve the signal-to-noise ratio at the receiving end. Even when the receiving end is far away, better signal quality can be obtained.

MIMO can greatly improve the network transmission rate, coverage and performance. When multiple independent spatial streams are transmitted simultaneously based on MIMO, the throughput of the system can be doubled. The number of spatial streams supported by MIMO system depends on the minimum value of transmitting antenna and receiving antenna. If the number of transmitting antennas is 3 and the number of receiving antennas is 2, the supported spatial stream is 2. In the market, after three years of mass production running-in period of 3×3 mode, 4X4 mode appeared this year, which immediately attracted the attention of the industry.