Beam Management
- (Toronto, Canada - Wei-Jiun Su)
- Antenna Array
An antenna array (often called a phased array) is a set of 2 or more antennas. The signals from the antennas are combined or processed in order to achieve improved performance over that of a single antenna. The antenna array can be used to: increase the overall gain; provide diversity reception; cancel out interference from a particular set of directions; "steer" the array so that it is most sensitive in a particular direction; determine the direction of arrival of the incoming signals; and to maximize the Signal to Interference Plus Noise Ratio (SINR).
An antenna array is a set of N spatially separated antennas. The number of antennas in an array can be as small as 2, or as large as several thousand (as in the AN/FPS-85 Phased Array Radar Facility operated by U. S. Air Force). In general, the performance of an antenna array (for whatever application it is being used) increases with the number of antennas (elements) in the array; the drawback of course is the increased cost, size, and complexity. Cell-tower Antenna Array are typically used in groups of 3 (2 receive antennas and 1 transmit antenna).
The value and utility of an antenna array lies in its ability to determine (or alter) the received or transmitted power as a function of the arrival angle. By choosing the weights and geometry of an antenna array properly, the phased array can be designed to cancel out energy from undesirable directions and receive energy most sensitively from other directions.
- Beam and Beam Management
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.
In case of low / mid frequency region without using massive antenna array, a single transmission would cover a lot of UEs simultaneously. However, when the radiation become beam-shaped, it is very difficult to cover multiple UEs in single transmission unless those multiple UEs are located in very close proximity. To handle this problem, we need a very sophisticated idea of managing/controlling the beam to cover the multiple devices scattered in all directions and the management/control mechanism should be different depending on the situtations.
[More to come ...]
