Dramatic Improvement in Wi-Fi 802.11ac/n Performance

Beamforming is an important companion to 4x4 Multiple Input Multiple Output (MIMO) technology for Wi-Fi wireless networking. When it is included, it enables dramatic improvement in Wi-Fi 802.11ac/n performance, reliability, range and coverage.

Beamforming is a signal processing technique used to control the directionality of the transmission and reception of radio signals. The most effective type of beamforming is dynamic digital beamforming. This type of beamforming uses an advanced, on-chip digital signal processing (DSP) algorithm to gain complete control over Wi-Fi signals. By creating several independent signal paths to optimally focus radio energy to and from client devices on a per-packet basis, performance is dramatically improved. In the case of a two-stream configuration, this makes it possible to steer the energy of the antenna array in the independent spatial directions associated with both data streams, while simultaneously avoiding interference.

Dynamic Digital Beamforming in a 4x4 MIMO System with Two Data Streams

Supports Two Data Streams and Provides Two Extra Transmit Antennas

When combined with 4x4 MIMO, dynamic digital beamforming is particularly powerful. This is because a 4x4 MIMO system supports two data streams and provides two extra transmit antennas that may be used for beamforming, to allow significant focusing of the energy in two directions while reducing interference with coexisting systems. This type of combined solution can deliver from 12 to 25 dB of system gains relative to 802.11ac/n wireless LAN systems without dynamic digital transmit beamforming.

The combination of 4x4 MIMO with dynamic digital beamforming also is adaptive, which means it can constantly adjust Wi-Fi performance based on real-time events. In other words, it optimally adapts the transmit antenna array pattern to the spatial characteristics of the MIMO channel frequency response, and also to the number of data streams and receiver positions. As a result, it can improve high-speed performance and consistency over longer distances.

In contrast, a 3x3 system transmitting two data streams has significantly lower reliability since there is only one extra antenna to focus energy in the two required directions. A 2x2 system gets very little benefit from transmit beamforming since has only the minimum required antennas. While dynamic digital beamforming works with any number of receive antennas, it is most powerful in a 4x4 MIMO configuration.