Fundamentals

1
Chapter 3 ???????

• Fundamentals
• of Cellular Communications

2
????

• ???????????(interference)???????,???????????????
• ???????????????????????????????
• ??????????????????????????????(frequency
  reuse)?????(multiple access),??????????????????(ce
  ll splitting)????

3
????

• ??????????
• ??????
• ??????
• ??????
• ??????
• ????
• ??
• ??

4
Section 3.1??????????Concept of Cellular Network
5
?????(Cellular Network)

• ??????????
• ??????????,??????????????,????????????????????????
  ???????????(cellular network)????
• ??3-1
• ????????????,?????
• ?????????
• ?????????????

6
? 3-1 ??????
7
???(Base Station)

• ???????????????????
• ???????????????
• ?????
• ???????
• ???????,?????????
• ??????,????????????

8
?????

• ??????????????,????????????
• ????????
• ?????(directional antenna),?3-3
• ?????(omni directional antenna),?3-4
• ????????
• ???????????,?3-5
• ????????????,?3-6

9
? 3-2 ???????????
???????????(main lobe)?120o
???????????????360o
10
? 3-3 ?????
11
? 3-4 ?????
12
? 3-5 ????
13
? 3-6 ???????????
14
??

• ????????????(cell)?
• ???(macrocell)????????????
• ???(microcell)????????????
• ?????
• ???????????????,????????????,???????????????????
• ??????????????????????????????????????????????????
  ??,????????????

15
?????

• ????????,??????? ???????????
• ??????????????

?3-8 ?????????????
?3-7 ?????????????
16
Section 3.2??????Interference
17
??????(frequency reuse)

• ?????????????????,??????????????????????,?????????
  ??

??(cluster)
?
?
cell
?
?
?
?
18
??????

• ???????????????????
• ????????????????????? ????????????,?????????
• ????????????,
• ???????(co-channel interference)
• ????????(adjacent channel Interference)

19
???????

• ?????????????,?????????,??????????????
• ????????????,??????????????????,??????????????????
  ?????????
• ??????????????????????????,????????,??????????????
  ?,???????????????????????????????????????

20
????????

• ???????????????????,????????????????????????,?????
  ?????????????????
• ????????????????,??????????????,????????????????
• ??????????????,????????????????????????

21
????(Near-far Effect)

• ??????????????????,??????,???????????????????????,
  ??????????????,?????????????????????????????

22
Section 3.3??????Frequency Reuse
23
????

• ???????????????????????,????????????????(frequency
  planning)?
• ???????????,?????4/12?7/21???
• 7/21?????????7??????,??????????3???????3??????,???
  ????21????
• 4/12?????3-9?

24
? 3-9 ??????
25
????(Cell Planning)

• ????????????????????,?????????????????,???????????
  ???????
• ????,???????????????????????
• ???????????????????
• ????????????????????,?????????????????????????????
  ??????????????,?????????????

26
??????? (1/2)

• ????????????(?GSM)?
• ??2D/3D?????
• ?????????(???????????????)?
• ???????????????
• ??????????
• ?????????(??????????????)?

27
??????? (2/2)

• ????????????,??????????
• ???????????????????????????
• ?????????????,??????

28
Section 3.4??????Capability Improvement
29
?????????

• ????(cell splitting)
• ???????(sectoring)
• ???/??????(macrocell/microcell architecture)

30
????

• ???????????????,??????????

31
???????

• ?????,??????????????????,???????,?????????????????

???? (sector)
?????
?????
? 3-11 ?????????120??????
32
???/??????

• ???/??????????????????(??????),?????????????????,?
  ?????????
• ???????????????????????

33
Section 3.5??????Quality Improvement
34
???????

• ?????(no network)??????????????????,?????????????
  ????????????,?????????
• ??(drop call)???????(forced termination)?????????
  ?????,?????????????
• ??(block call)???????????????????,???????????????
  ??,?????

35
????????? (1/2)

• ??
• ???????????????????,?????????????,??????????????
• ???????????
• ???????????
• ?????????????????,????????????????????,???????????
  ???????,????????????
• ?????,??????????????

36
????????? (2/2)

• ???????
• ????????,??????????????????
• ????????????????????
• ??????????????(main lobe)?????,?????????

37
???????

• ??????????????,?????????????
• ????????????????????,??????????
• ???????????????(diversity)
• ?????(space diversity)
• ?????(polarization diversity)
• ?????(frequency diversity)

38
?????

• ???????????,????????????????,??????????????????

39
?????

• ?????????????,????????????,????????
• ??????????????
• 45