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Tutorial 5 Mobile Communication Networks. Mohamed Esam. 6. 4. 3. 6. 4. 3. 1. 2. 5. 1. 6. 7. 2. 5. 4. 3. 6. 7. 4. 3. 6. 1. 4. 3. 2. 5. 1. 7. 2. 5. 1. 2. 5. 6. 7. 4. 3. 6. 7. 4. 3. 1. 2. 5. 1. Cell Planning. 2. 5. 7. 7. Co-Channel Interference.
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Tutorial 5Mobile Communication Networks Mohamed Esam
6 4 3 6 4 3 1 2 5 1 6 7 2 5 4 3 6 7 4 3 6 1 4 3 2 5 1 7 2 5 1 2 5 6 7 4 3 6 7 4 3 1 2 5 1 Cell Planning 2 5 7 7
Co-Channel Interference • I Co-channel Interference • For Omni frequency planning: • It means that the network is extended in all directions This relation is valid only for omni planning.
C/I (User) Complex math as depends on the user position. • Assume the average position (Base Station position)
Omni planning: 1 1 7 1 3 3 3 4 5 1 2 5 9 2 5 1 7 4 7 7 5 4 7 6 7 6 9 3 4 6 2 9 6 3 4 8 11 8 9 1 11 8 8 9 1 10 1 5 6 10 7 1 5 6 12 3 3 12 2 3 3 4 2 5 2 5 2 1 8 5 2 9 4 1 8 7 4 7 4 7 5 6 6 9 7 6 9 3 4 6 2 11 3 4 8 11 8 9 1 8 1 10 9 1 10 6 5 7 12 3 5 6 12 3 2 3 5 4 2 5 2 2 8 7 9 4 8 7 4 5 6 6 9 6 8 2 N=12 D=6 R 11 8 10 8 N=9 D=27^0.5 R 12
4 • Frequencies-Cell distribution: If operator has 21 carrier frequencies in N=7 cell. Cell 1 f1 ,f8 and f15 Cell 2 f2, f9 and f16 Cell 3 f3, f10 and f17 Cell 4 f4, f11 and f18 Cell 5 f5, f12 and f19 Cell 6 f6, f13 and f20 Cell 7 f7, f14 and f21 3 5 1 F1/f8/f15 2 6 7
Adjacent Channel Interference (ACI) • Due to incomplete filtering of unwanted modulation products in FM systems. 1 2 Worst case @ d1=d2 where C/I min= 26dB d2 Due to the distance between the adjacent cells Added by the Rx filters as shown in figure above d1 1 2 d2 d1
4 • Frequencies-Cell distribution: If operator has 21 carrier frequencies in N=7 cell. Cell 1 f1 ,f8 and f15 Cell 2 f2, f9 and f16 Cell 3 f3, f10 and f17 Cell 4 f4, f11 and f18 Cell 5 f5, f12 and f19 Cell 6 f6, f13 and f20 Cell 7 f7, f14 and f21 3 5 1 2 6 7 Adjacent Interference
6 Less Adjacent Interference • Here in cell1: • C/Imin = 26 dB (although it’s interfered by two adjacent cells) 4 3 1 2 5 7 7 2 1 C I
Each cell is affected by both Cochannel and Adjacent channel interference, so: • C/I total = the least one • If C/I (Cochannel) > C/I Adjacent: • C/I total= C/I Adj • Else: • C/I total = C/I Cochannel. 6 4 3 6 4 3 1 2 5 1 6 2 5 7 4 3 6 7 3 6 1 4 4 3 2 5 1 7 5 1 2 2 5 6 7 4 3 6 7 4 3 1 5 2 1 2 5 7 7
Problem-2-a • Channels/cell= Total No. of channels/N =10 log(1/6 * ) =5.44 dB 6 4 3 6 4 3 1 2 5 1 6 7 2 5 4 3 6 7 4 3 6 1 4 3 2 5 1 1 F1/f8/f15 7 2 5 1 2 5 6 7 4 3 6 7 4 3 1 2 5 1 2 5 7 7
Pr-3-b: 120 Sectorization • Channels/sector= Total No. of channels/(3*N) =10 log(1/2 * ) = 10.21 dB All cells are sectorized 6 4 3 6 4 3 1 2 5 1 6 7 2 5 4 3 6 7 4 3 6 1 F8 F1 f15 2 4 3 5 1 7 2 5 1 2 5 6 7 4 3 6 7 4 3 1 2 5 1 2 5 7 7
Pr-3-c: 60 Sectorization • Channels/sector= Total No. of channels/(6*N) =10 log(1/1 * ) = 13.22 dB All cells are sectorized 6 4 3 6 1 4 3 1 2 5 6 7 2 5 4 3 6 7 1 4 3 6 1 4 3 2 5 1 7 2 5 2 5 6 7 4 3 6 7 1 4 3 1 2 5 2 5 7 7