Cellular Networks PDF

Cellular networks Hexagonal cell y Dka = 2 R cos(p ) = 3R 6 R 3,2 u π/6...

Cellular networks Hexagonal cell y Dka = 2 R cos(p ) = 3R 6 R 3,2 u π/6 x Coordinate y i = n i + u i sin(p ), 6 transformation: xi = u i cos(p ) 6 Distance between two cells Distance between two points D can be expressed as: D 2 = ( x 2 - x1 ) 2 + ( y 2 - y1 ) 2 = [(n 2 - n 1 ) + (u 2 - u1 ) sin(p )] 2 6 1 3 + (u 2 - u1 ) 2 cos 2 (p ) = [(n 2 - n 1 ) + (u 2 - u1 )] 2 + (u 2 - u1 ) 2 = 6 2 4 = (u 2 - u1 ) 2 + (n 2 - n 1 ) 2 + (n 2 - n 1 )(u 2 - u1 ) In this way we can express distance from center of coordinates (when it is at the center of origin cell) to the center of any hexagon: 2 2 2 D k = (u k - 0) 2 + (n k - 0) 2 + (n k - 0)(u k - 0) = u k + n k + n k u k = = 3R 2 (i 2 + j 2 + ij ) Here coordinates u, v of the center of k-th hexagon are replaced by integer numbers i, j of distances between neighboring hexagons Clusters of cells B C B 1,1 A 1,1 C u B B A C C B A A C 1,1 B A C 1,1 1,1 A The largest group of neighboring cells that do not have overlapping cells is called a cluster. Clusters of cells Cluster area: Cell area: 2 6 Dk 3 6 3 2 3 S cl = = 3R 2 (i 2 + j 2 + ij ) SN = ( R) = 3R 2 3 4 2 3 2 2 Number of cells in a cluster: 2 2 N c = (i + j + ij ) A A Dk = R 3(i 2 + j 2 + ij ) Clusters of cells Main cluster parameters i j Nc Dk/R S/I, dB 1 0 1 1,73 0 1 1 3 3 16,1 2 0 4 3,46 16,8 2 1 7 4,58 18,7 3 0 9 5,2 19,6 2 2 12 6 20,7 3 1 13 6,24 21 Clusters i=2 j=0 of cells i=1 j=1 Nc=4 Nc=3 -Narvelis A i=2 -Narvelis B j=1 -Narvelis C Nc=7 -Narvelis D -Narvelis E -Narvelis F -Narvelis H Co-channel interference Signal to noise ration can be expressed as: S Ps = N PN + PI Here PS, PN and PI are signal, noise and interference powers, respectively. Suppose PN