Voronoi-based coverage optimization for multi-femtocells

Suppose a rectangle place with 9 femtocells denoted by “+”, and the femtocells are deployed previously. After conducting voronoi diagram construction, the two-object optimization problem is solved. Set the size of the rectangle place as 30×30m
²
, and W = [w
i=1…9
= 0.5]
1×9
. Fig 2.3 is the optimized result. Compared with Fig 2.1, which is the result with maximum radius, the overlap area is reduced, which can reduce the interference among femtocells, besides, the interference between femtocells and macrocell is also reduced because there's less radio coverage area reaching out of the rectangle place in Fig 2.3. Compared with Fig 2.2, which is the result with minimum radius, the nunlap area is visibly reduced, thus the network capacity is correspondingly improved. Based on the optimal r, the minimum transmitting power of each base station can be acquired by the formula E
i,T,min
= r
i
^α
E
i,R,min
, i = 1, 2, …, M.