7 BEAMFORMING
Beamforming is a technique used by intelligent antennas to shape their array pattern in a preferred direction
(see Figure 4). This is done to maximize the signal to target users and minimize interference from other users.
The result is an improved Signal-to-Interference-plus-Noise (SNIR) ratio that increases signal throughput and
system capacity.
Here is how it works: a user’s device communicates with one antenna when a user is standing in one place.
However, if the user begins moving or stands somewhere else, the device will communicate with a different
antenna. In response, all the other antennas reduce their output power. So essentially, every user gets a unique
optimized signal.
USER -
POSITION C
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USER - POSITION B
USER - POSITION A
FIGURE 4: Beamforming illustration showing the shaping of array patterns.
While intelligent antennas are already being deployed in some cell towers, it is unlikely that they will be
used for indoor solutions due to cost and taking up more space than traditional DAS coverage antennas. What
may transpire, however, is the development of intelligent remotes for indoor solutions.
Similar to antenna beamforming, intelligent remotes could reduce the overall noise impact to the system
and optimize throughput by working together. Some remotes would output more power to provide a stronger
signal to the users, while other remotes that are serving areas where there are no users would reactively shut
off their signal. Essentially, remotes would be able to “make the decision” to power off at the component level,
rather than relying on the base transceiver station (BTS) to control the amount of power being directed to the
remotes in response to nontraffic or high-traffic situations.
While intelligent antennas are already being deployed in some cell towers, it is
unlikely that they will be used for indoor solutions due to cost and taking up more
space than traditional DAS coverage antennas. What may transpire, however,
is the development of intelligent remotes for indoor solutions.