Reasons:
1.Because these directional antenna only receive signals in particular direction,the amount of interference power they receive assuming a clustersize of 7 is reduced by 1/3.
2.With less interference power, the speech quality is much better than it needs to be.
3.So we can reduce the clustersize (increase interference power) and still have good speech quality.
4.Trials show that in systems with 120 degree antenna, the clustersize can be as small as 3.
5.This allows more users to be supported, while keeping cell size fixed.
Because of the benefits offered by 120 degree antenna, these are most readily used by base station towers.....
No comments:
Post a Comment