Slide No,1Advanced Learning Solutions
Slide 1
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CDMA Technology and
Operations for Unicom
Senior Managers
CDMA Radio Design Principles
CDMA 无线设计原理
CDMA Radio Design
Principles
Slide No,2Advanced Learning Solutions
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CDMA Radio Design Principles
Topics 主 题
Coverage （ 覆盖）
Reverse and Forward link
反向和前向链路
A CDMA Link Budget （ CDMA 链路预算
）
Capacity （ 容量）
Reverse and forward link
capacity 反向和前向链路容量
Search Windows （ 搜索窗口）
Network Dimensioning （ 网络规模）
Carriers （ 载波）
Channel Elements （ 信道单元
）
Slide No,3Advanced Learning Solutions
Slide 3
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CDMA Radio Design Principles
Part 1 Coverage
第 1 部分 覆盖
Slide No,4Advanced Learning Solutions
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CDMA Radio Design Principles
Coverage Analysis
覆盖研究
CDMA coverage analysis has many dimensions
CDMA 覆盖研究具有许多方面
Idle Mode
Pilot Coverage
空闲模式导频覆盖
Traffic Channel
Coverage
业务信道覆盖
Forward Link
前向链路
Relative Fwd
Powers
相对前向功率
Traffic mode
Pilot Coverage
业务模式导频覆盖
Traffic
Channel
业务信道
Reverse Link
反向链路
Access
Channel
接入信道
Slide No,5Advanced Learning Solutions
Slide 5
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CDMA Radio Design Principles
Coverage Analysis
覆盖研究
Idle Mode
Pilot Coverage
空闲模式导频覆盖
Traffic Channel
Coverage
业务信道覆盖
Forward Link
前向链路
Relative Fwd
Powers
相对前向功率
Traffic mode
Pilot Coverage
业务模式导频覆盖
Traffic
Channel
业务信道
Reverse Link
反向链路
Access
Channel
接入信道
Slide No,6Advanced Learning Solutions
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Traffic Channel Reverse Link Equation
业务信道反向链路均衡
Eb/It at the BTS receiver（ BTS 接收机的 Eb/It ）,
W
I
I
V A FIN
RP
WIIN
RP
I
E
sc
oc
sco
brx
ocsco
brx
t
b
/1
/
/
/
VAF = Voice Activity Factor (typically 0.4 to 0.5)
VAF = 话音激活因子 (通常为 0.4 到 0.5)
Assume （ 假设）
perfect power control （ 完全功率控制）
Eb/It = G?
Isc = (Nu-1)Prx
Solve for Prx （解答 Prx）
Slide No,7Advanced Learning Solutions
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Reverse Link Equation 反向链路均衡
Received full-rate Power per user,
每个用户 接收到的全速率功率：
W/R = spreading ratio (128 for EVRC) W/R = 扩展比率 (128 for EVRC)
F = Isc/(Isc+Ioc)
G= required Eb/No (typ,7 dB) （ G = 要求的 Eb/No (typ,7 dB))
Nu = number of simultaneous users (Nu =同时作用的用户数量 )
VAF = mean voice activity factor (typ 0.45)
VAF = 平均话音激活因子 (通常为 0.45)
NoW = total equivalent noise at the BTS (NoW = BTS 上等价噪声的总和 )
)1(G?
G
u
o
rx
N
F
V A FRW
WN
P
Slide No,8Advanced Learning Solutions
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Reverse Link Interference
反向链路干扰
Ioc
Isc
Reverse link interference comes from in-
cell and out-of-cell mobiles
来自于进小区和出小区移动台的反向链路干扰
In-cell mobiles are power controlled by the
BTS
进小区移动台由 BTS 进行功率控制
Out-of-cell mobiles are power controlled
by other BTS
出小区移动台由其他 BTS进行功率控制
Interference comes from a large number
of distributed mobiles
干扰来自于许多分布式移动台
ocsc
sc
II
IF
Slide No,9Advanced Learning Solutions
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Total Receive Power
总接收功率
Total Receive power includes in-cell and out-of-cell interference,plus thermal noise
总接收功率包括进小区和出小区干扰,加上热噪声
G
G
F
NV A F
RW
FNV A F
WN
FIWN
IIWNP
u
u
o
sco
ocsco
t o t a l
rx
)1(
/
1
/
Noise Rise
噪声增益等式 1
Slide No,10Advanced Learning Solutions
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Example
实例
Assume （ 假设）：
F = 0.66,VAF = 0.4,W/R = 128
W = 1.25 MHz,R = 9.6 kbps
NoW = k T B FBTS = -174 dBm/Hz + 10log(1250000) + 4 dB = -109 dBm
- 1 1 4,9
- 1 1 2,1
- 9 7 d B m
- 1 0 1 d B m
- 1 3 0,0
- 1 2 5,0
- 1 2 0,0
- 1 1 5,0
- 1 1 0,0
- 1 0 5,0
- 1 0 0,0
- 9 5,0
- 9 0,0
- 8 5,0
- 8 0,0
0 10 20 30 40 50
N
d
B
m
P r x
P t o t a l
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Reverse Link
反向链路
Pole capacity （ 极点容量）：
depends only on G,VAF and F （ 仅依赖于 G,VAF和 F）
does notdepend on NoW （ 不 依赖于 NoW）
NoW affects only the sensitivity and coverage,not capacity
NoW 仅影响灵敏度和覆盖,不是容量
Includes both BTS noise and external interference
包括 BTS 噪声和外部干扰
Avoid operating near,pole” （ 避免在靠近,极点,的地方操作）
–Typically < 50%-70% of Npole （ 有代表性的 < 50%-70% of Npole）
F can vary in practice because （ F 会在实际中有变化，这是因为）
–propagation conditions （ 传播条件），
–sector antenna patterns （ 扇形天线模式），
–other cells loadings etc.（ 其他小区负载等等）。
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Noise Rise
噪声增益
The noise-rise term in equation 1 indicates the reduction in
coverage that all mobiles will experience,
等式 1中的噪声增益术语表示所有移动台都会经历的覆盖范围的减少。
Normally,the noise-rise due to loading should be maintained to
be less than 3 dB or so,
通常，由于有负载，噪声增益应该保持在少于大约 3 dB 左右。
External interference can also contribute to Noise-rise and loss
of coverage
内部干扰也会增加噪声增益并使覆盖范围减少。
Slide No,13Advanced Learning Solutions
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Noise Rise vs loading Example
噪声增益与负载对比实例
This chart shows the
measured noise rise on
a real BTS as traffic
levels change
此表显示当业务层变化时在一个 BTS上测量的噪声增益
A noise rise of around 3
to 4 dB occurs for 13
erlangs
出现 13 erlang 时噪声增益在 3 到 4 dB
Slide No,14Advanced Learning Solutions
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Coverage Analysis
覆盖研究
Idle Mode
Pilot Coverage
空闲模式导频覆盖
Traffic Channel
Coverage
业务信道覆盖
Forward Link
前向链路
Relative Fwd
Powers
相对前向功率
Traffic mode
Pilot Coverage
业务模式导频覆盖
Traffic
Channel
业务信道
Reverse Link
反向链路
Access
Channel
接入信道
Slide No,15Advanced Learning Solutions
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Forward Link Power Relationships
前向链路功率关系
Unused power （ 不用的功率）
Pilot
Paging
Sync
TCH-1
TCH-2
TCH-3
OverheadPwr
开销功率
Ptraffic
MaxPwr
TrafficLoading = Ptraffic/(MaxPwr – Poverhead)
业务负载 = Ptraffic/(MaxPwr – Poverhead)
Overhead powers set as a fixed % of
MaxPwr
开销功率设置为 MaxPwr的固定值％
Each traffic channel power varies
independently by Forward Link Power
control
每一个业务信道根据前向链路功率控制独立的改变
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Recommended Forward Link Powers
推荐的前向链路功率
% of MaxPwr Watts
(MaxPwr = 15W)
Pilot
导频 13 % 1.95 W
Paging
寻呼 5% (Halfrate)10% (full-rate) 0.75 W1.5 W
Sync
同步 2% 0.3 W
Max Traffic Lower / Upper
最大业务量低的 /高的 1% / 13% 0.15 W / 1.95W
Slide No,17Advanced Learning Solutions
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Power and Digital Gain
功率和数字增益
Powers in most CDMA BTS are set using,Digital Gain” parameters and values
在很多 CDMA BTS 中功率是用,数字增益,参数和值来设置的
Digital gains are used internally in the BTS demodulator chipsets (CSMs),and also externally in
the BSC to control BTS power (eg forward link power control)
数字增益内用在解调器码片组 (CSM) 中,而且外用在 BSC 以控制 BTS 功率 (如前向链路功率控制 )
Q Short Code
I Short Code
S
cos(wct)
sin(wct)
HPA
G0
G64
W0
W63
Digital Gains
数字增益
Slide No,18Advanced Learning Solutions
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Digital Gains
数字增益
Digital Gain values take on integer values
数字增益值是整数
Typically G = 0,2,4...…254
典型的 G = 0,2,4......254
Digital Gain values are voltage gains and map to the power domain as
follows,
数字增益值是电压增益并映射到功率域如下所示：
K is known as the,calibration setpoint or constant”,and maps digital
gain to a power at some reference point (usually at the BTS output).
K是,校准设置点或常数,,并映射数字增益到位于一些参考点（通常是
BTS输出）的功率值上。
2
1
1 2 5 4*
GKP
Slide No,19Advanced Learning Solutions
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Channel Powers
信道功率
KS y n c h P w r
KP a g in g P w r
KP il o tP w r
2
2
2
254
254
254
S y n c G ai n
P a gi n gG ai n
P i lo t G a i n
Digital Gains can also be used to set thresholds for admitting new calls
and handoffs (Nortel and Ericsson only)
数字增益也可以用来为接听新的呼叫和切换 (仅 Nortel 和 Ericsson 适用 )
设置门限
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Digital Gain Example
数字增益实例
Assume that（ 假设） DG= 2542? 4 W
i.e.（ 即） (254/254)2 *K = 4
K = 4
Channel
信道
Digital Gain
数字增益
Power at BTS output
在 BTS 输出的功率
Pilot
导频
150 4*(150/254)2= 1.4 W
Paging
寻呼
70 0.3 W
Synch
同步
50 0.15 W
Slide No,21Advanced Learning Solutions
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Coverage Analysis
覆盖研究
Idle Mode
Pilot Coverage
空闲模式导频覆盖
Traffic Channel
Coverage
业务信道覆盖
Forward Link
前向链路
Relative Fwd
Powers
相对前向功率
Traffic mode
Pilot Coverage
业务模式导频覆盖
Traffic
Channel
业务信道
Reverse Link
反向链路
Access
Channel
接入信道
In idle mode,mobiles only demodulate one pilot at a time and measure
the relative pilot strengths (Ec/Io)
在空闲模式，移动台在一个时间只解调一个导频并测量相对导频强度
(Ec/Io)
Slide No,22Advanced Learning Solutions
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Ec/Io
Ec/Io is a measure of a pilot strength （ Ec/Io 是导频强度的测量标准）
Ec is the energy in one chip interval （ Ec 是一个码片间隔的能量）
Joules in 0.81 msec （ Joules 在 0.81 msec）
Io is the total noise plus interference power spectral density
Io 是总噪声加上干扰功率频谱密度
includes the wanted pilot （ 包括要求的导频）
specified in watts/Hz （ 指定用 watts/Hz）
Ec/Io can be related to the received Pilot power and noise power (in watts),
Ec/Io 和接收到的导频功率和噪声功率有关 (以 watts为单位 ):
ocscrx
p i l o t
ocscrx
cp i l o t
o
c
IIN
P
WIIN
RP
I
E
/
/
Slide No,23Advanced Learning Solutions
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Ec/Io Example – Isolated BTS
Ec/Io 实例 – 孤立的 BTS
Maximum available forward link power = 15 W (42 dBm)
最大可用前向链路功率 = 15 W (42 dBm)
Pilot power = 2 W,Paging Power = 1 W,Sync power = 0.2
W
导频功率 = 2 W,寻呼功率 = 1 W,同步功率 = 0.2 W
With no traffic loading and close to BTS,
若没有业务负载并靠近 BTS：
Ec/Io = 10 log10( 2 / (2+1+0.2)) = - 2 dB
With full traffic loading and close to BTS,
若满业务负载并靠近 BTS：
Ec/Io = 10 log (2 /15) = -8.75 dB
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Ec/Io as a function of pathloss
Ec/Io 作为路径损耗的函数
Ec/Io
Ec/Io is constant until the edge of coverage or other BTS pilots are received
Ec/Io 一直为常数直到覆盖的边缘或者收到其他的 BTS 导频
Ec/Io cannot be used to measure coverage margin
Ec/Io 不能用来测量覆盖边际
Pathloss（ 路径损耗）
0 dB Increasing loading（ 增加负荷）
Slide No,25Advanced Learning Solutions
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Ec/Io for 2 BTS （ Ec/Io 在 2 BTS情况下）
2 BTS 的仿真
M o bi l e P aram e te rs B TS P aram e te rs B S - 1 B S - 2
Ma x P w r 1 5,0 W 1 5,0 W
M S _M a x_T x_P w r 2 3 d B m Pw r Pi l o t 2,0 W 2,0 W
T _A DD - 1 4,0 d B 28 3 3,0 d B m 3 3,0 d B m
NoW - 1 1 3,0 Pw r S yn c h 0,2 W 0,2 W
M S NF 8,0 d B Pw r Pa gi n g 2,0 W 2,0 W
NoW *NF - 1 0 5 d B m T CH Loa di ng 0 % 50 %
3,2E - 14 P_ T CH 0,0 W 5,4 W
M S A n t G a in 0,0 d B i P_ T o ta l 4,2 W 9,6 W
S ta r t Dis ta n c e 0 k m 3 6,2 d B m 3 9,8 d B m
Dis ta n c e In c r e m e n t 1 k m fe e d e r l o s s 3 d B 3 d B
A n t G a in 1 5 d B i 1 5 d B i
Clutte r L o s s 1 0,0 d B S e n s - 1 2 3 d B m - 1 2 3 d B m
BT S Loca t ions B T S - 1 B T S - 2
x 0,0 km 1 0,0 km
y 0,0 km 0,0 km
A n te n n a He i gh t 1 00 m 30 m
x
y
BS-1 BS-2
Slide No,26Advanced Learning Solutions
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Ec/Io
Note SHO region is smaller between BTS
注意 SHO 区域在 BTS 之间很小
Large region of SHO to the right of BS-2
SHO 的大区域位于 BS-2 的右边
E c / I o a n d H a n d o f f S t a t e
- 2 5,0
- 2 0,0
- 1 5,0
- 1 0,0
- 5,0
0,0
0 5 10 15 20 25 30
d i s t a n c e ( k m )
E
c
/
I
o
(
d
B
)
0
1
2
3
4
5
H
a
n
d
o
f
f
S
t
a
t
e
E c / I o _ 1
E c / I o _ 2
B S - 1
B S - 2
S H O _ S T A T E
Slide No,27Advanced Learning Solutions
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RSSI
R SSI
- 1 1 0,0
- 9 0,0
- 7 0,0
- 5 0,0
- 3 0,0
- 1 0,0
1 0,0
0 5 10 15 20 25 30
R S S I _ 1
R S S I _ 2
R S S I _ T o t a l _ 1
Slide No,28Advanced Learning Solutions
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Mobile Transmit Power
移动传输功率
Mobiles will transmit with the least transmitter power
移动台会以最小发射台功率进行传输
MX T X Po w e r
- 5 0,0
- 4 0,0
- 3 0,0
- 2 0,0
- 1 0,0
0,0
1 0,0
2 0,0
0 5 10 15 20 25 30
d i s t a n c e ( k m )
d
B
m
M S _ T X 1
M S _ T X 2
M S _ T x
Slide No,29Advanced Learning Solutions
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Forward Link Interference Model
前向链路干扰模型
Location x is assumed to be close to the cell border,A mobile at
x receives interference from one or more BTS.
位置 x 假定接近小区边缘。位于 x的移动台接收到从一个或多个
BTS 来的干扰。
Same-cell interference (Isc) and out-of-cell interference (Ioc)
相同小区干扰 (Isc) 和出小区干扰 (Ioc)
This is conveniently approximated as a ratio Isc/Ioc.
为了方便表示为 比值 Isc/Ioc。
For an isolated BTS,
对于孤立的 BTS）：
Isc/Ioc
For two equal strength signals:
对于两个相同强度的信号：
Isc/Ioc? 1 (0 dB)
For three equal strength signal:
对于三个相同强度的信号：
Isc/Ioc? 1/2 (-3 dB)
Ioc
Isc
Note,Isc and Ioc are not the same as used for
the reverse link
注意,Isc 和 Ioc 和在反向链路中使用的不同。
x
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Forward Link Interference Model
前向链路干扰模型
This equation allows us to specify Isc as a ratio of Isc
这个等式使得大家可以用 Isc的 比值 来说明 Isc
scocscrx
p i l o t
ocscrx
p i l o t
o
c
IIIN
P
IIN
P
I
E
/1
Slide No,31Advanced Learning Solutions
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Predicting CDMA Coverage
预测 CDMA 覆盖
Cell planning tools typically use the pilot power to predict coverage and produce
coverage maps
小区规划工具典型的采用导频功率来预测覆盖并画出覆盖范围图
The planning tool will create a prediction with a pilot signal,
规划工具会用导频信号产生一个预测：
Pilot power at minimum required Ec/Io（导频功率最小需 Ec/Io）
Pilot power at the reverse link boundary （ 在反向链路边界的导频功率）
The coverage is predicted by contouring at a received pilot power level
calculated from a link budget,
覆盖范围是由从链路预算计算的接收到的导频功率层作出的等值线来预测的。
Note that this is not what a mobile would measure as total receive power (RSSI)
注意这个预测 不 是移动台作为总的接收功率 (RSSI) 所要测量的内容。
RSSI includes pilot,paging,sync and traffic from all nearby BTS
RSSI 包括从所有邻近的 BTS发出的导频、寻呼、同步和业务。
Slide No,32Advanced Learning Solutions
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Part 2 A CDMA Link
Budget
第 2 部分 CDMA 链路预算
Slide No,33Advanced Learning Solutions
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System Model 系统模型
BTS
GBS GMS
Ptx
MSCable
Forward Link （ 前向链路）
Feeder
TOR
MS AntennaBS Antenna
BTS
GBS GMS
TPL = Lpath +Lfeeder- Gbs
Prx
MSCableFeeder
Reverse Link （ 反向链路）
Lpath
Lpath
Noise Figure FBTS
Slide No,34Advanced Learning Solutions
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CDMA Radio Design Principles
Link Budget- Reverse Link
链路预算 - 反向链路
Dens e
Ur ba n Ur ba n S ub urban Hi gh w ay Rur al
Rur al
Is ol ate d
Rev e rs e Link
E b/No 7.5 7.5 7.5 7.5 7.5 7.5 dB
B T S Feede r Lo s s 3 3 3 3 3 3 dB
B T S Noi s e Fi gu r e 4 4 4 4 4 4 dB
k T B - 11 3 - 11 3 - 11 3 - 11 3 - 11 3 - 11 3 dB m
CDMA P r oc es s i ng G ai n 21 21 21 21 21 21 dB
Reqd S i gn al A t B T S A nte nn a T erm i na l s - 11 9.4 - 11 9.4 - 11 9.4 - 11 9.4 - 11 9.4 - 11 9.4 dB m
Reqd S i gn al at B T S Rx In pu t - 12 2.4 - 12 2.4 - 12 2.4 - 12 2.4 - 12 2.4 - 12 2.4 dB m
Ma x,M ob i l e T x P w r 23 23 23 23 23 23 dbm
Mo bi l e e f f ec ti v e a nte nn a g ai n 0 0 0 0 0 0 dB i
B S A nte nn a Gai n 15 15 15 15 15 15 dB i
Ma x A l l ow ab l e P ath Lo s s ( no m argi ns ) 157.4 157.4 157.4 157.4 157.4 157.4 dB
M ar g ins
Reqd A r ea Cov erage 95% 95% 95% 95% 95% 95%
P r op ag ati on Con s tan t (n) 3.5 3.5 3.5 3.5 3.5 3.5
P r ob s erv i c e a t Cel l ed ge 79% 78% 78% 78% 76% 76%
S ha do w i ng S td Dev i ati on 10 8 8 8 6 6 dB
P en etrati on l os s S td Dev 0 0 0 0 0 0 dB
T ota l Fade S td Dev 10.0 8.0 8.0 8.0 6.0 6.0 dB
S ha do w i ng Ma r gi n 8.2 6.2 6.2 6.2 4.2 4.2 dB
S HO G ai n 4 4 3 3 2 0 dB
T ota l Fade Ma r gi n 4.2 2.2 3.2 3.2 2.2 4.2 dB
B od y Lo s s Ma r gi n 3 3 3 3 3 3 dB
F i x ed B l g P en etrati on Lo s s 0 0 0 0 0 0 dB
E x ternal In terf erenc e M argi n 0.0 0.0 0.0 0.0 0.0 0.0 dB
Lo ad i ng m argi n 3 3 3 3 1.5 1.5 dB
T ota l Ma r gi ns 10.2 8.2 9.2 9.2 6.7 8.7 dB
M ax A llow able S t r ee t le v el P ath loss (w it h mar g ins) 147.3 149.2 148.2 148.2 150.7 148.7 dB
M ax A v ail able T r ansmission P ath loss 135 137 136 136 139 137 dB
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Link Budget – Forward Link
链路预算 – 前向链路
Dens e
Ur ba n Ur ba n S ub urban Hi gh w ay Rur al
Rur al
Is ol ate d
Rev e rs e Link
M ax A llow able S t r ee t le v el P ath loss (w it h mar g ins) 147.3 149.2 148.2 148.2 150.7 148.7 dB
M ax A v ail able T r ansmission P ath loss 135 137 136 136 139 137 dB
Forw a rd Li nk
T ota l HP A po w er 15.0 15.0 15.0 15.0 15.0 15.0 W
% Pi l ot 13% 13% 13% 13% 13% 12%
% Pa gi ng 10% 10% 10% 10% 10% 10%
%Sy nc h 2% 2% 2% 2% 2% 2%
P i l ot P ow er 2.0 2.0 2.0 2.0 2.0 1.8 W
P ag i ng P ow er 0.01 0.01 0.01 0.01 0.01 0.01 W
S y nc h P ow er 0.00 0.00 0.00 0.00 0.00 0.00 W
T CH P ow er Max W
T CH l oa di ng 50% 50% 50% 50% 50% 50%
T ota l Fw d T x P ow er 8.5 8.5 8.5 8.5 8.5 8.4 dB m
Cel l E dg e I s c /Io c -3 -3 -3 -3 -3 20 dB
F ee de r Lo s s 3 3 3 3 3 3 dB
B T S A nte nn a Gai n (dB i ) 15 15 15 15 15 15 dB i
MS NF 8.0 8.0 8.0 8.0 8.0 8.0 dB
NoW = k T B F - 10 5 - 11 3 - 11 3 - 11 3 - 11 3 - 11 3 dB m
Rx P i l ot po w er - 10 2 - 10 4 - 10 3 - 10 3 - 10 6 - 10 4 dB m
Is c - 96 - 98 - 97 - 97 - 99 - 97 dB m
Ioc + Is c + NoW - 91,0 - 93,1 - 92,1 - 92,1 - 94,6 - 97,3 dB m
E c /Io at Rev B ou nd ary - 11,3 - 11,2 - 11,2 - 11,2 - 11,2 - 6.9 dB
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Using Tower Mounted Low Noise Amplifiers采用塔式固定低噪声放大器
TT-LNAs can be used to improve reverse link coverage
TT-LNA 可以用来提高反向链路覆盖
A TT-LNA minimises the impact of the feeder loss
TT-LNA 使得馈线损耗的影响最小
A TT-LNA can sometimes have a better NF than the BTS
TT-LNA 有时会比 BTS 具有更好的 NF
LNATT-LNA
Gain (G1) Noise Figure (F1)
增益 (G1) 噪声指数 (F1)
BTS
Feeder
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Using Tower Mounted LNAs
采用塔式固定 LNA
LNATT-LNA
Lfeeder
G3
F3
G1
F1 G2 = 1/LfeederF2 = Lfeeder
BTS
321
21
3
1
2
1
11
GGGG
GG
F
G
FFF
eq
eq
eqeq kTBFN?
Use the Friis equation to calculate the composite Noise Figure and Gain of the cascaded devices
采用 Friis 等式计算合成噪声指数 和级联设备的增益
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TT-LNA Example
TT-LNA 实例
Parameter
参数
dB Value
dB值
Linear Value
线性值
F1 1 dB 1.26
G1 15 dB 31.6
L2 = Lfeeder 3 dB 2
G3 = -Lfeeder -3 dB 0.5
F3 4 dB 2.51
)dB42.1(39.1
5.06.31
151.2
6.31
1226.1
eqF
d B m4.1 1 1
dB42.1d B m8.1 1 2
eqeq k T B FN
Neq is the equivalent noise at the TT-LNA input,Neq
是 TT-LNA输入的等价噪声。
The noise power at the BTS input will be (in dBm),
BTS输入的噪声功率是 (用 dBm):
NBTS =Neq +G1- L2 = -111.4 + 15 – 3 = -99.4 dBm
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TT-LNA Summary
TT-LNA 摘要
While the TT-LNA can improve the reverse link (typically by as
much as 5 dB),the forward link may become the limiting link,
在 TT-LNA可能增加反向链路 (尤其增加 5 dB)的同时，前向链路可能会成为受限链路。
To balance the links and maximise coverage,the forward link
power would need to be increased
为了均衡链路并达到最大限度的覆盖，前向链路功率需要增加。
Telstra uses this approach in Rural areas with the Nortel
“Boomer” BTS
Telstra在农村地区将此方法用于 Nortel的,Boomer”BTS。
15W? 65 W (6.4 dB)
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Part 3 Capacity
第 3 部分 容量
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Review of Erlang Theory
Erlang 理论的回顾
Poisson Arrival Process （ 泊松到达过程）
Mean Inter-arrival rate l （ 平均中间到达率 l）
Negative Exponentially distributed Hold times
负对数分布维持时间
Mean Hold time m （ 平均维持时间 m ）
Offered Erlang Load A = l/ m erlangs
提供的 Erlang 负载 A = l/ m erlangs
Probability distribution of offered number of calls,
提供的的呼叫数量的分布概率：
Given C serving channels,probability of blocking (Lost Calls
Cleared),（ 假定 C是服务信道，阻塞概率 (清除丢失呼叫 )：
mlml e
kp
k
k !
C
n
n
C
C
n
Cp
0
!/
!/
ml
ml
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Probability of Offered Calls
提供的呼叫概率
Example,（ 实例）
A = l/ m = 10 erlang
0,2
0
p k 10?( )
200 k
0 5 10 15 20
0
0,0 5
0,1
0,1 5
The number of calls in the system is a
random variable
系统中呼叫的数量是随机分布
The Normal Distribution is a useful
approximation to pk,
正态分布是 pk.的有用的近似
Mean = A,s = A
mlml e
k
p
k
k !
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TDMA/FDMA Erlang and Channel Capacity
TDMA/FDMA Erlang 和信道容量
Example （ 实例）
GSM with 4/12 reuse and 42 frequencies,
GSM 具有 4/12 重用和 42个频率
Frequencies per sector = 42/12 = 3.5
频率 \扇区 = 42/12 = 3.5
TCH Timeslots per sector = 3.5*8 –1 = 27
TCH 时隙 \扇区 = 3.5*8 –1 = 27
Channel Capacity = 27
信道容量 = 27
Erlang Capacity = ErlangB(27,2%) = 19.2 E Erlang
容量 = ErlangB(27,2%) = 19.2 E
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Forward Link Traffic Channel Capacity
前向链路业务信道容量
Forward link power is shared between
前向链路功率由以下两个共享：
Primary links （ 主链路）
Secondary links (soft and softer handoff)
第二链路 (软和更软切换 )
BTS2BTS2
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Forward Power Depends on Mobile Location前向功率依赖于移动台位置
These graphs show random mobile locations and required forward
link traffic channel power to achieve Eb/No = 10 dB at the mobile
这些图表显示的是随机的移动台的位置以及要求的前向链路业务信道功率以得到在移动台的 Eb/No = 10 dB
Wanted cell Mobile locations.
-20.00
-15.00
-10.00
-5.00
0.00
5.00
10.00
15.00
20.00
-20.00 -15.00 -10.00 -5.00 0.00 5.00 10.00 15.00 20.00
0,0 0 0
1,0 0 0
2,0 0 0
3,0 0 0
4,0 0 0
5,0 0 0
6,0 0 0
7,0 0 0
8,0 0 0
9,0 0 0
1 0,0 0 0
1
27 53 79
105 131 157 183 209 235 261 287 313 339 365 391 417 443 469 495
Sa m p l e
F
w
d
T
C
H
Po
w
e
r
(W
)
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Single Cell Simulation of Forward Power
前向功率的单个小区仿真
Cell radius = 2 km （ 小区半径 = 2 km）
Hata Suburban Model with 20 dB clutter loss,shadowing Std
Dev = 8 dB
Hata 郊区模型有 20 dB 散射损耗,阴影 Std Dev = 8 dB
MS NF = 8 dB,Eb/No = 10 dB (-116 dBm traffic channel
sensitivity)
MS NF = 8 dB,Eb/No = 10 dB (-116 dBm 业务信道灵敏度 )
Max Fwd power = 15 W,Overhead power = 25%
最大前向功率 = 15 W,开销功率 = 25%
10 Erlangs of offered traffic (no SHO)
10 Erlang 所提供的业务 (无 SHO)
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Sample Simulation Results
实例仿真结果
T o ta l T x P o w e r
0,0
5,0
1 0,0
1 5,0
0 10 20 30 40 50 60 70 80 90 100
I n s t a n c e
W
a
t
ts
T o ta l T x P o w e r
0,0
5,0
1 0,0
1 5,0
0 10 20 30 40 50 60 70 80 90 100
I n s t a n c e
W
a
t
ts
R = 2 km
R = 3 km
Total Power > MaxPwr
总功率 > 最大功率
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CDMA Channel and Traffic Capacity
CDMA 信道和业务容量
CDMA Channel Capacity is not fixed（ CDMA 信道容量不是固定的）
depends on F,VAF,Isc and Ioc
（依赖于 F,VAF,Isc 和 Ioc）
also depends on user locations and SHO
（ 也依赖于用户位置和 SHO）
CDMA has a,soft” capacity limit （ CDMA 有一个,软,容量限制）
Current practical estimates （ 当前实用的评估）
Offered Traffic at 2% Blocking
在 2%阻塞时提供的业务
Equivalent Channel Capacity
等价信道容量
IS95A,EVRC 13 E 20 channels
1xRTT EVRC 19.5 E 28 channels
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Monte Carlo Simulations 蒙特卡罗仿真
CDMA coverage and capacity depends on,
CDMA 覆盖和容量依赖于：
Mobile locations (affecting noise-rise and
forward power) 移动台的位置 (影响噪声增益和前向功率 )
Radio channels (multipath) and Mobile speed
(both affecting Eb/No) 无线信道 (多径 ) 和移动速度 (都会影响 Eb/No)
Simulation is one way of analysing the statistical nature of CDMA
coverage and capacity performance
仿真是分析 CDMA 覆盖和容量性能的统计特性的一种方式
Most CDMA planning tools include a,Monte-Carlo” tool for simulating
coverage and capacity performance
大多数 CDMA 规划工具都包括,蒙特卡罗,工具，用于进行覆盖和容量性能仿真
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Monte-Carlo Simulations
蒙特卡罗仿真
Monte-carlo simulation provides a series of
“snapshots” of N mobile locations.
蒙特卡罗仿真提供了 N个移动台位置的一连串的,快照”
Mobile profiles include Eb/No,in-building
probabilities etc,
移动台分布图包括 Eb/No,建筑物内的概率等等。
Results are stored for each,run” or,drop”.
对每个,运行,或者,掉线,结果都予以储存。
Results from K,drops” are averaged to
obtain mean and percentile values at each
grid location (eg 90th percentile for Mobile
Transmit power).
从 K 个“掉线,得到的结果经过平均得到在每一个格子位置的平均值和百分点值 (如移动台传输功率的第 90个百分点 )。
Generate random
locations for N mobiles
产生 N个移动台随机位置
Start （ 开始）
Iterate to find stable solution
for Reverse and Fwd Tx
powers
为反向和前向 Tx功率重复寻找稳定的解决方案
Traffic Density
map
业务密度图
Mobile Profiles
移动台分布图
Write Results
写结果
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Monte-Carlo Simulations
蒙特卡罗仿真
Monte-Carlo simulations require significant processing time
蒙特卡罗仿真需要相当长的处理时间
Questionable benefit for coverage designs
覆盖设计的益出让人质疑
Many inputs and assumptions required
需要很多输入和假设
Standard techniques using link budgets and power contouring are more
straight forward
采用链路预算和功率等值线的标准技术更加直接
Monte-Carlo useful for analysing,what-if” scenarios and developing
strategies to optimise capacity in problem areas
蒙特卡罗对于分析,what-if” 情况和在问题区域制定策略以优选容量很有用处
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Part 4 Search Window Design
第 4 部分 搜索窗口的设计
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The role of PN Offsets
PN 偏置的作用
IS95 is a synchronous system （ IS95 是一个同步系统）
GPS used to lock transmitted pilot signals to < 3 us of GPS (UTC) time
（ GPS 以前用于锁定传输给 < 3 us GPS (UTC) 时间的导频信号
Each Sector transmits a Pilot signal（每个扇区传输一个导频信号）
defined by a PN number,512 PNs defined in IS95,
由 PN 号码定义。 有 512 个 PN 定义在 IS95中。
1 PN = 64 chips spacing （ 码片间隔）
Allowable PNs in a system determined by PILOT_INC parameters
系统中允许的 PN是由 PILOT_INC 参数决定的
Example （ 实例）,PILOT_INC = 3。 Allowable PNs （ 允许的
PNs） = 0,2,5….
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Example 1
实例 1
3 BTS
0.75,1.5 and 3 km from
mobile 距离移动台 0.75,
1.5 和 3km
Mobile derives time from BTS-1 (strongest)
移动台以 BTS-1 时间为准 (最强的 )
Relative delay of BTS-2 （ BTS-2相对延时）
1.5 – 0.75 = 0.75 km
= 3.1 chips
Relative delay of BTS-3 （ BTS-3相对延时）
3 – 0.75 = 2.25 km
= 9.225 chips
0.75 km
1.5 km
3 km
BTS-1
BTS-3
BTS-2
1 chip = 0.814ms = 244 metres
4.1 chips per km
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Example 1 Timing Diagram
实例 1 时间表
MS Time
BTS-1
BTS-2
30
60
30 60
BTS-2
90
3.1 chips (0.75km) 6.2 chips (1.5 km)
90
12.3 chips (3 km)
Search Window
搜索窗口
Search Window
搜索窗口
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Search Window Size搜索窗口的大小
Window width too small
窗口的宽度太小
Cannot capture useful
multipath energy
不能捕获有用的多径能量
Signals outside window
contributes to Io in Ec/Io
窗口外的信号对于 Ec/Io中的 Io也起作用
Window width too large
窗口的宽度太大
Mobile search time takes
longer
移动台搜索时间会更长
During the search period
the signal may cause large
interference as it is not
added to active set yet
在搜索期内由于信号还不加到现行的设置上因此会产生大的干扰。110.4 (?55.2)45215
78.1 (?39.05)32014
55.2 (?27.6)22613
39.1 (?19.55)16012
31.7 (?15.65)13011
24.4 (?12.2)10010
19.5 (?9.75)809
14.6 (?7.3)608
9.8 (? 4.8)407
6.8 (? 3.4)286
4.9 (? 2.45)205
3.4 (? 1.7)14 4
2.4 (? 1.2)103
2.0 (? 1)82
1.5 (? 0.75)61
1.0 (? 0.5)40
Window Size
(km)
Window Size
(PN Chips)
SCHWIN
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Calculating SCHWINs
计算 SCHWINs
Soft Handoff Region
dmax = |d2 –d1|
Window size（ 窗口大小） T > 2 * (dmax/c + tmax) / Tchip chips
Where（ 其中） c = 3x108 m/s,Tc = chip interval = 0.814 ms
d1 d2
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P N O f f s e t D i s t r i b u t i o n
0
10
20
30
40
50
60
70
-2
5
-2
3
-2
1
-1
9
-1
7
-1
5
-1
3
-1
1
-9 -7 -5 -3 -1
1 3 5 7 9
11 13 15 17 19 21 23 25
C h i p O f f s e t s
B
i
n
C
o
u
n
t
Graph of PN Offset distributions
PN 偏置分布图
The plot of a PN offset distribution can assist in tuning the search window widths,These offsets are reported
in PSMMs,（ PN 偏置分布图对调节窗口的宽度有帮助。这些偏置在 PSMM中有报告。）
Window must be wide
enough to capture
useful multipaths
窗口要足够宽以捕获有用的多径
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Graph of PN Offset distributions (cont)
PN 偏置分布图 (续 )
Survey tools such as Nortel RFO can report where multipaths
(in chips) are measured,
调查工具如 Nortel RFO 可以报告在哪里测量多径 (按码片 ) 。
Histograms can also be produced from PSMM,The signal
strengths of pilots reported in PSMM are recorded in phase
offsets,eg PILOT_PN_PHASE = 7170 chips = PN112 + 2 chips,
柱状图也可以从 PSMM产生。在 PSMM中报告的导频的信号强度记录在相位偏置中，如导频 _PN_相位 = 7170 chips = PN112 + 2
chips.
From this,one can deduce that this particular multipath is 2
chips away from the centre of the search window
由此，我们可以推断这个特定的多径偏离搜索窗口中心 2个码片
。
By collecting PSMM from live traffic,one can choose the optimal
search window width for the environment being studied,
通过从活动业务中收集 PSMM,我们可以为正在研究的环境选择最佳的搜索窗口。
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CDMA Radio Design Principles
Part 5 Radio Resource
Management
第 5 部分 无线资源管理
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What is Radio Resource Management?
什么是无线资源管理?
RRM is the management of the physical and logical resources
involved in setting up and maintaining a call
RRM 是对建立和维护一个呼叫所涉及的物理和逻辑资源的管理
Resources can include （ 资源可以包括）：
channel elements （ 信道单元）
power （ 功率）
Walsh codes （ Walsh 码）
RRM algorithms are required to manage,
需要用 RRM算法进行管理：
Call admission （ 呼叫接入）
Call handoff （ 呼叫切换）
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Radio Resource Management across Multiple Carriers
通过多载波的无线资源管理
IS95A is inherently different to conventional FDMA systems such as GSM
or AMPS IS95A 和传统上的
FDMA 系统如 GSM 或者 AMPS有内在的差异
There are few features to allow mobiles to search for other frequencies
（ 几乎没有特怔允许移动台搜寻其他的频率）
searching is limited to PNs on the same carrier frequency
搜索限制在位于 同一 个载波频率的 PN中
IS95B introduced a feature to allow mobiles to search PNs on other
frequencies IS95B介绍了一个特征，可以允许移动台搜索位于其他频率的 PN
Not widely used（ 没有广泛采用）
Limited support for this feature in mobiles
移动台对于这个特征的支持有限
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Idle Mode Distribution of Traffic
业务的空闲模式分配
On power up,mobiles acquire the Primary Carrier
当加电时，移动台接到主载波
Mobiles read a channel list from the system parameters
message
移动台从系统参数消息中读取信道列表
Mobiles perform a,hashing” function to determine which carrier
to select for idle mode
移动台完成,散列法,操作以确定选择哪一个载波作为空闲模式
A function of mobile MIN （ 移动台 MIN
的功能）
Mobiles retune to the calculated carrier frequency
移动台回到计算出来的载波频率上
Mobile originate calls on the selected carrier frequency
移动台在所选的载波频率发出呼叫
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Distribution of Traffic at Call Setup
呼叫建立时业务的分配
Some vendors offer Multi-carrier selection algorithms (eg Nortel MCTA)
一些供应商提供多载波选择算法 (如 Nortel MCTA)
All Mobiles idle and stay on FA1
所有的移动台空闲并保持在 FA1
Mobiles are directed to least loaded or preferred carrier at call
setup
移动台在 呼叫建立 时被转向最少负载的或者首选的载波）
Example（实例）
Mobile idles on FA1 (Channel 283 )
移动台空闲在 FA1 (信道 283)
Call set-up,Mobile directed to FA3 (Channel 242)
呼叫建立。移动台被转到 FA3 (信道 242)
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Example 1 – Pilot Beacon Hard Handoff
实例 1 – 导频标志硬切换
Mobile originates a call at A,Directed to set-up on PN40/FA2
移动台在 A开始一个呼叫 。 直接建立在 PN40/FA2
FA1
FA2
Distance（ 距离）
A
PN40 PN70PN10
B
Mobile travels to B,Reports PN70 from Pilot Beacon sector
移动台到 B。 从导频标志扇区报告 PN70
Mobile directed to hard handoff to FA1 (PN40,PN70)
移动台直接硬切换到 FA1 (PN40,PN70)
Goes directly into SHO with PN70,PN40 on FA1
在 FA1上用 PN70,PN40直接转到 SHO
Pilot Beacon
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Mode Distribution of Traffic – Call Setup
业务的业务模式分配 – 呼叫建立
Neighbour sectors can be data filled in the Pilot Data
Base as beacons,and can be used to trigger a Hard
Handoff to another carrier
相邻扇区可以在导频数据库中被数据填充作为标志，
并可以用于触发硬切换到其它载波
Dedicated Pilot Beacons can also be used
也可以使用专用导频标志
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Example 2 – RTD Hard Handoff
实例 2 – RTD 硬切换
FA1
FA2
Distanc（ 距离）PN40 PN70PN10
Some Vendors (Nortel and Ericsson) offer Round Trip Delay feature to
trigger a hard handoff
一些供应商 (Nortel和 Ericsson) 提供往复延时特性以触发一个硬切换
The handoff is initiated when the mobile exceeds a specified RTD
threshold
（ 当移动台超出指定的 RTD门限时即开始进行切换）
The RTD threshold is expressed in units of km or 1/8 chips (approx 30m)
RTD 门限是以 km或者 1/8chips (大约 30m)为单位来表示的
This has advantages as Pilot Beacon Hardware is not required on
surrounding sectors
这样就会有优势，因为在周围扇区不需要导频标志硬件 RTD threshold distance （ RTD门限距离）
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Example 2 – RTD Hard Handoff
实例 2 – RTD 硬切换
FA1
FA2
Distance（ 距离）
A
PN40 PN70PN10
B
Mobile originates at A and is directed to setup on PN40/FA2
移动台在 A开始并直接建立在 PN40/FA2
Mobile travels towards B （ 移动台移动到 B）
A RTD handoff trigger occurs when the mobile reaches B
当移动台到达 B 时 RTD 硬切换触发电路工作
The mobile is directed to handoff to FA1（ 移动台直接切换到 FA1） (PN10,
PN40 和 PN70)
handoff would be a multi-pilot handoff to PN10,PN40 and PN70
对于 PN10,PN40 和 PN70 切换将是多导频切换
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Multi-carrier Strategies
多载波策略
If one sector requires a second carrier,all sectors on the BTS require a
second carrier
如果一个扇区需要第二个载波，在 BTS 上所有扇区都需要第二个载波
RTD can be used for isolated BTS （ RTD 可以用于孤立的 BTS）
may not be reliable in small cells with multi-path
有多径的小扇区可能不可靠
Aim to spread traffic evenly across all sectors and BTS in a geographic
area
（ 旨在一个地理区域在所有扇区和 BTS 均匀地扩展业务）
all BTS in area upgraded to 2nd carrier at the same time
同一区域中所有 BTS 同时被提高到 第二个载波
use repeaters where feasible （ 在可行的地方使用中继器）
new BTS （ 新 BTS）
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Multi-Pilot Hard Handoff (MPHHO)
多导频硬切换 (MPHHO)
IS95 allows mobiles to hard-handoff to up to 6 target PNs
IS95允许移动台硬切换升至 6目标 PN
This is useful where there may be several possible targets
这在有几个可能的目标时会很有用
In Example 2 the handoff would be to PN10,PN40 and PN70
在实例 2中会切换到 PN10,PN40 和 PN70
Most vendors implement this
大部分供应商都执行此功能
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Part 5 Network
Dimensioning
第 5 部分 网络规模
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Capacity Dimensioning
容量规模
BTS
Carriers
载波
Channel Elements
信道单元
Slide 1
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CDMA 无线设计原理
CDMA Radio Design
Principles
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Topics 主 题
Coverage （ 覆盖）
Reverse and Forward link
反向和前向链路
A CDMA Link Budget （ CDMA 链路预算
）
Capacity （ 容量）
Reverse and forward link
capacity 反向和前向链路容量
Search Windows （ 搜索窗口）
Network Dimensioning （ 网络规模）
Carriers （ 载波）
Channel Elements （ 信道单元
）
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Part 1 Coverage
第 1 部分 覆盖
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Coverage Analysis
覆盖研究
CDMA coverage analysis has many dimensions
CDMA 覆盖研究具有许多方面
Idle Mode
Pilot Coverage
空闲模式导频覆盖
Traffic Channel
Coverage
业务信道覆盖
Forward Link
前向链路
Relative Fwd
Powers
相对前向功率
Traffic mode
Pilot Coverage
业务模式导频覆盖
Traffic
Channel
业务信道
Reverse Link
反向链路
Access
Channel
接入信道
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Coverage Analysis
覆盖研究
Idle Mode
Pilot Coverage
空闲模式导频覆盖
Traffic Channel
Coverage
业务信道覆盖
Forward Link
前向链路
Relative Fwd
Powers
相对前向功率
Traffic mode
Pilot Coverage
业务模式导频覆盖
Traffic
Channel
业务信道
Reverse Link
反向链路
Access
Channel
接入信道
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Traffic Channel Reverse Link Equation
业务信道反向链路均衡
Eb/It at the BTS receiver（ BTS 接收机的 Eb/It ）,
W
I
I
V A FIN
RP
WIIN
RP
I
E
sc
oc
sco
brx
ocsco
brx
t
b
/1
/
/
/
VAF = Voice Activity Factor (typically 0.4 to 0.5)
VAF = 话音激活因子 (通常为 0.4 到 0.5)
Assume （ 假设）
perfect power control （ 完全功率控制）
Eb/It = G?
Isc = (Nu-1)Prx
Solve for Prx （解答 Prx）
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Reverse Link Equation 反向链路均衡
Received full-rate Power per user,
每个用户 接收到的全速率功率：
W/R = spreading ratio (128 for EVRC) W/R = 扩展比率 (128 for EVRC)
F = Isc/(Isc+Ioc)
G= required Eb/No (typ,7 dB) （ G = 要求的 Eb/No (typ,7 dB))
Nu = number of simultaneous users (Nu =同时作用的用户数量 )
VAF = mean voice activity factor (typ 0.45)
VAF = 平均话音激活因子 (通常为 0.45)
NoW = total equivalent noise at the BTS (NoW = BTS 上等价噪声的总和 )
)1(G?
G
u
o
rx
N
F
V A FRW
WN
P
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Reverse Link Interference
反向链路干扰
Ioc
Isc
Reverse link interference comes from in-
cell and out-of-cell mobiles
来自于进小区和出小区移动台的反向链路干扰
In-cell mobiles are power controlled by the
BTS
进小区移动台由 BTS 进行功率控制
Out-of-cell mobiles are power controlled
by other BTS
出小区移动台由其他 BTS进行功率控制
Interference comes from a large number
of distributed mobiles
干扰来自于许多分布式移动台
ocsc
sc
II
IF
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Total Receive Power
总接收功率
Total Receive power includes in-cell and out-of-cell interference,plus thermal noise
总接收功率包括进小区和出小区干扰,加上热噪声
G
G
F
NV A F
RW
FNV A F
WN
FIWN
IIWNP
u
u
o
sco
ocsco
t o t a l
rx
)1(
/
1
/
Noise Rise
噪声增益等式 1
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Example
实例
Assume （ 假设）：
F = 0.66,VAF = 0.4,W/R = 128
W = 1.25 MHz,R = 9.6 kbps
NoW = k T B FBTS = -174 dBm/Hz + 10log(1250000) + 4 dB = -109 dBm
- 1 1 4,9
- 1 1 2,1
- 9 7 d B m
- 1 0 1 d B m
- 1 3 0,0
- 1 2 5,0
- 1 2 0,0
- 1 1 5,0
- 1 1 0,0
- 1 0 5,0
- 1 0 0,0
- 9 5,0
- 9 0,0
- 8 5,0
- 8 0,0
0 10 20 30 40 50
N
d
B
m
P r x
P t o t a l
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Reverse Link
反向链路
Pole capacity （ 极点容量）：
depends only on G,VAF and F （ 仅依赖于 G,VAF和 F）
does notdepend on NoW （ 不 依赖于 NoW）
NoW affects only the sensitivity and coverage,not capacity
NoW 仅影响灵敏度和覆盖,不是容量
Includes both BTS noise and external interference
包括 BTS 噪声和外部干扰
Avoid operating near,pole” （ 避免在靠近,极点,的地方操作）
–Typically < 50%-70% of Npole （ 有代表性的 < 50%-70% of Npole）
F can vary in practice because （ F 会在实际中有变化，这是因为）
–propagation conditions （ 传播条件），
–sector antenna patterns （ 扇形天线模式），
–other cells loadings etc.（ 其他小区负载等等）。
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Noise Rise
噪声增益
The noise-rise term in equation 1 indicates the reduction in
coverage that all mobiles will experience,
等式 1中的噪声增益术语表示所有移动台都会经历的覆盖范围的减少。
Normally,the noise-rise due to loading should be maintained to
be less than 3 dB or so,
通常，由于有负载，噪声增益应该保持在少于大约 3 dB 左右。
External interference can also contribute to Noise-rise and loss
of coverage
内部干扰也会增加噪声增益并使覆盖范围减少。
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Noise Rise vs loading Example
噪声增益与负载对比实例
This chart shows the
measured noise rise on
a real BTS as traffic
levels change
此表显示当业务层变化时在一个 BTS上测量的噪声增益
A noise rise of around 3
to 4 dB occurs for 13
erlangs
出现 13 erlang 时噪声增益在 3 到 4 dB
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Coverage Analysis
覆盖研究
Idle Mode
Pilot Coverage
空闲模式导频覆盖
Traffic Channel
Coverage
业务信道覆盖
Forward Link
前向链路
Relative Fwd
Powers
相对前向功率
Traffic mode
Pilot Coverage
业务模式导频覆盖
Traffic
Channel
业务信道
Reverse Link
反向链路
Access
Channel
接入信道
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Forward Link Power Relationships
前向链路功率关系
Unused power （ 不用的功率）
Pilot
Paging
Sync
TCH-1
TCH-2
TCH-3
OverheadPwr
开销功率
Ptraffic
MaxPwr
TrafficLoading = Ptraffic/(MaxPwr – Poverhead)
业务负载 = Ptraffic/(MaxPwr – Poverhead)
Overhead powers set as a fixed % of
MaxPwr
开销功率设置为 MaxPwr的固定值％
Each traffic channel power varies
independently by Forward Link Power
control
每一个业务信道根据前向链路功率控制独立的改变
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Recommended Forward Link Powers
推荐的前向链路功率
% of MaxPwr Watts
(MaxPwr = 15W)
Pilot
导频 13 % 1.95 W
Paging
寻呼 5% (Halfrate)10% (full-rate) 0.75 W1.5 W
Sync
同步 2% 0.3 W
Max Traffic Lower / Upper
最大业务量低的 /高的 1% / 13% 0.15 W / 1.95W
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Power and Digital Gain
功率和数字增益
Powers in most CDMA BTS are set using,Digital Gain” parameters and values
在很多 CDMA BTS 中功率是用,数字增益,参数和值来设置的
Digital gains are used internally in the BTS demodulator chipsets (CSMs),and also externally in
the BSC to control BTS power (eg forward link power control)
数字增益内用在解调器码片组 (CSM) 中,而且外用在 BSC 以控制 BTS 功率 (如前向链路功率控制 )
Q Short Code
I Short Code
S
cos(wct)
sin(wct)
HPA
G0
G64
W0
W63
Digital Gains
数字增益
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Digital Gains
数字增益
Digital Gain values take on integer values
数字增益值是整数
Typically G = 0,2,4...…254
典型的 G = 0,2,4......254
Digital Gain values are voltage gains and map to the power domain as
follows,
数字增益值是电压增益并映射到功率域如下所示：
K is known as the,calibration setpoint or constant”,and maps digital
gain to a power at some reference point (usually at the BTS output).
K是,校准设置点或常数,,并映射数字增益到位于一些参考点（通常是
BTS输出）的功率值上。
2
1
1 2 5 4*
GKP
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Channel Powers
信道功率
KS y n c h P w r
KP a g in g P w r
KP il o tP w r
2
2
2
254
254
254
S y n c G ai n
P a gi n gG ai n
P i lo t G a i n
Digital Gains can also be used to set thresholds for admitting new calls
and handoffs (Nortel and Ericsson only)
数字增益也可以用来为接听新的呼叫和切换 (仅 Nortel 和 Ericsson 适用 )
设置门限
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Digital Gain Example
数字增益实例
Assume that（ 假设） DG= 2542? 4 W
i.e.（ 即） (254/254)2 *K = 4
K = 4
Channel
信道
Digital Gain
数字增益
Power at BTS output
在 BTS 输出的功率
Pilot
导频
150 4*(150/254)2= 1.4 W
Paging
寻呼
70 0.3 W
Synch
同步
50 0.15 W
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Coverage Analysis
覆盖研究
Idle Mode
Pilot Coverage
空闲模式导频覆盖
Traffic Channel
Coverage
业务信道覆盖
Forward Link
前向链路
Relative Fwd
Powers
相对前向功率
Traffic mode
Pilot Coverage
业务模式导频覆盖
Traffic
Channel
业务信道
Reverse Link
反向链路
Access
Channel
接入信道
In idle mode,mobiles only demodulate one pilot at a time and measure
the relative pilot strengths (Ec/Io)
在空闲模式，移动台在一个时间只解调一个导频并测量相对导频强度
(Ec/Io)
Slide No,22Advanced Learning Solutions
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CDMA Radio Design Principles
Ec/Io
Ec/Io is a measure of a pilot strength （ Ec/Io 是导频强度的测量标准）
Ec is the energy in one chip interval （ Ec 是一个码片间隔的能量）
Joules in 0.81 msec （ Joules 在 0.81 msec）
Io is the total noise plus interference power spectral density
Io 是总噪声加上干扰功率频谱密度
includes the wanted pilot （ 包括要求的导频）
specified in watts/Hz （ 指定用 watts/Hz）
Ec/Io can be related to the received Pilot power and noise power (in watts),
Ec/Io 和接收到的导频功率和噪声功率有关 (以 watts为单位 ):
ocscrx
p i l o t
ocscrx
cp i l o t
o
c
IIN
P
WIIN
RP
I
E
/
/
Slide No,23Advanced Learning Solutions
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Ec/Io Example – Isolated BTS
Ec/Io 实例 – 孤立的 BTS
Maximum available forward link power = 15 W (42 dBm)
最大可用前向链路功率 = 15 W (42 dBm)
Pilot power = 2 W,Paging Power = 1 W,Sync power = 0.2
W
导频功率 = 2 W,寻呼功率 = 1 W,同步功率 = 0.2 W
With no traffic loading and close to BTS,
若没有业务负载并靠近 BTS：
Ec/Io = 10 log10( 2 / (2+1+0.2)) = - 2 dB
With full traffic loading and close to BTS,
若满业务负载并靠近 BTS：
Ec/Io = 10 log (2 /15) = -8.75 dB
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Ec/Io as a function of pathloss
Ec/Io 作为路径损耗的函数
Ec/Io
Ec/Io is constant until the edge of coverage or other BTS pilots are received
Ec/Io 一直为常数直到覆盖的边缘或者收到其他的 BTS 导频
Ec/Io cannot be used to measure coverage margin
Ec/Io 不能用来测量覆盖边际
Pathloss（ 路径损耗）
0 dB Increasing loading（ 增加负荷）
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Ec/Io for 2 BTS （ Ec/Io 在 2 BTS情况下）
2 BTS 的仿真
M o bi l e P aram e te rs B TS P aram e te rs B S - 1 B S - 2
Ma x P w r 1 5,0 W 1 5,0 W
M S _M a x_T x_P w r 2 3 d B m Pw r Pi l o t 2,0 W 2,0 W
T _A DD - 1 4,0 d B 28 3 3,0 d B m 3 3,0 d B m
NoW - 1 1 3,0 Pw r S yn c h 0,2 W 0,2 W
M S NF 8,0 d B Pw r Pa gi n g 2,0 W 2,0 W
NoW *NF - 1 0 5 d B m T CH Loa di ng 0 % 50 %
3,2E - 14 P_ T CH 0,0 W 5,4 W
M S A n t G a in 0,0 d B i P_ T o ta l 4,2 W 9,6 W
S ta r t Dis ta n c e 0 k m 3 6,2 d B m 3 9,8 d B m
Dis ta n c e In c r e m e n t 1 k m fe e d e r l o s s 3 d B 3 d B
A n t G a in 1 5 d B i 1 5 d B i
Clutte r L o s s 1 0,0 d B S e n s - 1 2 3 d B m - 1 2 3 d B m
BT S Loca t ions B T S - 1 B T S - 2
x 0,0 km 1 0,0 km
y 0,0 km 0,0 km
A n te n n a He i gh t 1 00 m 30 m
x
y
BS-1 BS-2
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Ec/Io
Note SHO region is smaller between BTS
注意 SHO 区域在 BTS 之间很小
Large region of SHO to the right of BS-2
SHO 的大区域位于 BS-2 的右边
E c / I o a n d H a n d o f f S t a t e
- 2 5,0
- 2 0,0
- 1 5,0
- 1 0,0
- 5,0
0,0
0 5 10 15 20 25 30
d i s t a n c e ( k m )
E
c
/
I
o
(
d
B
)
0
1
2
3
4
5
H
a
n
d
o
f
f
S
t
a
t
e
E c / I o _ 1
E c / I o _ 2
B S - 1
B S - 2
S H O _ S T A T E
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RSSI
R SSI
- 1 1 0,0
- 9 0,0
- 7 0,0
- 5 0,0
- 3 0,0
- 1 0,0
1 0,0
0 5 10 15 20 25 30
R S S I _ 1
R S S I _ 2
R S S I _ T o t a l _ 1
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Mobile Transmit Power
移动传输功率
Mobiles will transmit with the least transmitter power
移动台会以最小发射台功率进行传输
MX T X Po w e r
- 5 0,0
- 4 0,0
- 3 0,0
- 2 0,0
- 1 0,0
0,0
1 0,0
2 0,0
0 5 10 15 20 25 30
d i s t a n c e ( k m )
d
B
m
M S _ T X 1
M S _ T X 2
M S _ T x
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Forward Link Interference Model
前向链路干扰模型
Location x is assumed to be close to the cell border,A mobile at
x receives interference from one or more BTS.
位置 x 假定接近小区边缘。位于 x的移动台接收到从一个或多个
BTS 来的干扰。
Same-cell interference (Isc) and out-of-cell interference (Ioc)
相同小区干扰 (Isc) 和出小区干扰 (Ioc)
This is conveniently approximated as a ratio Isc/Ioc.
为了方便表示为 比值 Isc/Ioc。
For an isolated BTS,
对于孤立的 BTS）：
Isc/Ioc
For two equal strength signals:
对于两个相同强度的信号：
Isc/Ioc? 1 (0 dB)
For three equal strength signal:
对于三个相同强度的信号：
Isc/Ioc? 1/2 (-3 dB)
Ioc
Isc
Note,Isc and Ioc are not the same as used for
the reverse link
注意,Isc 和 Ioc 和在反向链路中使用的不同。
x
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Forward Link Interference Model
前向链路干扰模型
This equation allows us to specify Isc as a ratio of Isc
这个等式使得大家可以用 Isc的 比值 来说明 Isc
scocscrx
p i l o t
ocscrx
p i l o t
o
c
IIIN
P
IIN
P
I
E
/1
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Predicting CDMA Coverage
预测 CDMA 覆盖
Cell planning tools typically use the pilot power to predict coverage and produce
coverage maps
小区规划工具典型的采用导频功率来预测覆盖并画出覆盖范围图
The planning tool will create a prediction with a pilot signal,
规划工具会用导频信号产生一个预测：
Pilot power at minimum required Ec/Io（导频功率最小需 Ec/Io）
Pilot power at the reverse link boundary （ 在反向链路边界的导频功率）
The coverage is predicted by contouring at a received pilot power level
calculated from a link budget,
覆盖范围是由从链路预算计算的接收到的导频功率层作出的等值线来预测的。
Note that this is not what a mobile would measure as total receive power (RSSI)
注意这个预测 不 是移动台作为总的接收功率 (RSSI) 所要测量的内容。
RSSI includes pilot,paging,sync and traffic from all nearby BTS
RSSI 包括从所有邻近的 BTS发出的导频、寻呼、同步和业务。
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Part 2 A CDMA Link
Budget
第 2 部分 CDMA 链路预算
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System Model 系统模型
BTS
GBS GMS
Ptx
MSCable
Forward Link （ 前向链路）
Feeder
TOR
MS AntennaBS Antenna
BTS
GBS GMS
TPL = Lpath +Lfeeder- Gbs
Prx
MSCableFeeder
Reverse Link （ 反向链路）
Lpath
Lpath
Noise Figure FBTS
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Link Budget- Reverse Link
链路预算 - 反向链路
Dens e
Ur ba n Ur ba n S ub urban Hi gh w ay Rur al
Rur al
Is ol ate d
Rev e rs e Link
E b/No 7.5 7.5 7.5 7.5 7.5 7.5 dB
B T S Feede r Lo s s 3 3 3 3 3 3 dB
B T S Noi s e Fi gu r e 4 4 4 4 4 4 dB
k T B - 11 3 - 11 3 - 11 3 - 11 3 - 11 3 - 11 3 dB m
CDMA P r oc es s i ng G ai n 21 21 21 21 21 21 dB
Reqd S i gn al A t B T S A nte nn a T erm i na l s - 11 9.4 - 11 9.4 - 11 9.4 - 11 9.4 - 11 9.4 - 11 9.4 dB m
Reqd S i gn al at B T S Rx In pu t - 12 2.4 - 12 2.4 - 12 2.4 - 12 2.4 - 12 2.4 - 12 2.4 dB m
Ma x,M ob i l e T x P w r 23 23 23 23 23 23 dbm
Mo bi l e e f f ec ti v e a nte nn a g ai n 0 0 0 0 0 0 dB i
B S A nte nn a Gai n 15 15 15 15 15 15 dB i
Ma x A l l ow ab l e P ath Lo s s ( no m argi ns ) 157.4 157.4 157.4 157.4 157.4 157.4 dB
M ar g ins
Reqd A r ea Cov erage 95% 95% 95% 95% 95% 95%
P r op ag ati on Con s tan t (n) 3.5 3.5 3.5 3.5 3.5 3.5
P r ob s erv i c e a t Cel l ed ge 79% 78% 78% 78% 76% 76%
S ha do w i ng S td Dev i ati on 10 8 8 8 6 6 dB
P en etrati on l os s S td Dev 0 0 0 0 0 0 dB
T ota l Fade S td Dev 10.0 8.0 8.0 8.0 6.0 6.0 dB
S ha do w i ng Ma r gi n 8.2 6.2 6.2 6.2 4.2 4.2 dB
S HO G ai n 4 4 3 3 2 0 dB
T ota l Fade Ma r gi n 4.2 2.2 3.2 3.2 2.2 4.2 dB
B od y Lo s s Ma r gi n 3 3 3 3 3 3 dB
F i x ed B l g P en etrati on Lo s s 0 0 0 0 0 0 dB
E x ternal In terf erenc e M argi n 0.0 0.0 0.0 0.0 0.0 0.0 dB
Lo ad i ng m argi n 3 3 3 3 1.5 1.5 dB
T ota l Ma r gi ns 10.2 8.2 9.2 9.2 6.7 8.7 dB
M ax A llow able S t r ee t le v el P ath loss (w it h mar g ins) 147.3 149.2 148.2 148.2 150.7 148.7 dB
M ax A v ail able T r ansmission P ath loss 135 137 136 136 139 137 dB
Slide No,35Advanced Learning Solutions
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Link Budget – Forward Link
链路预算 – 前向链路
Dens e
Ur ba n Ur ba n S ub urban Hi gh w ay Rur al
Rur al
Is ol ate d
Rev e rs e Link
M ax A llow able S t r ee t le v el P ath loss (w it h mar g ins) 147.3 149.2 148.2 148.2 150.7 148.7 dB
M ax A v ail able T r ansmission P ath loss 135 137 136 136 139 137 dB
Forw a rd Li nk
T ota l HP A po w er 15.0 15.0 15.0 15.0 15.0 15.0 W
% Pi l ot 13% 13% 13% 13% 13% 12%
% Pa gi ng 10% 10% 10% 10% 10% 10%
%Sy nc h 2% 2% 2% 2% 2% 2%
P i l ot P ow er 2.0 2.0 2.0 2.0 2.0 1.8 W
P ag i ng P ow er 0.01 0.01 0.01 0.01 0.01 0.01 W
S y nc h P ow er 0.00 0.00 0.00 0.00 0.00 0.00 W
T CH P ow er Max W
T CH l oa di ng 50% 50% 50% 50% 50% 50%
T ota l Fw d T x P ow er 8.5 8.5 8.5 8.5 8.5 8.4 dB m
Cel l E dg e I s c /Io c -3 -3 -3 -3 -3 20 dB
F ee de r Lo s s 3 3 3 3 3 3 dB
B T S A nte nn a Gai n (dB i ) 15 15 15 15 15 15 dB i
MS NF 8.0 8.0 8.0 8.0 8.0 8.0 dB
NoW = k T B F - 10 5 - 11 3 - 11 3 - 11 3 - 11 3 - 11 3 dB m
Rx P i l ot po w er - 10 2 - 10 4 - 10 3 - 10 3 - 10 6 - 10 4 dB m
Is c - 96 - 98 - 97 - 97 - 99 - 97 dB m
Ioc + Is c + NoW - 91,0 - 93,1 - 92,1 - 92,1 - 94,6 - 97,3 dB m
E c /Io at Rev B ou nd ary - 11,3 - 11,2 - 11,2 - 11,2 - 11,2 - 6.9 dB
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Using Tower Mounted Low Noise Amplifiers采用塔式固定低噪声放大器
TT-LNAs can be used to improve reverse link coverage
TT-LNA 可以用来提高反向链路覆盖
A TT-LNA minimises the impact of the feeder loss
TT-LNA 使得馈线损耗的影响最小
A TT-LNA can sometimes have a better NF than the BTS
TT-LNA 有时会比 BTS 具有更好的 NF
LNATT-LNA
Gain (G1) Noise Figure (F1)
增益 (G1) 噪声指数 (F1)
BTS
Feeder
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Using Tower Mounted LNAs
采用塔式固定 LNA
LNATT-LNA
Lfeeder
G3
F3
G1
F1 G2 = 1/LfeederF2 = Lfeeder
BTS
321
21
3
1
2
1
11
GGGG
GG
F
G
FFF
eq
eq
eqeq kTBFN?
Use the Friis equation to calculate the composite Noise Figure and Gain of the cascaded devices
采用 Friis 等式计算合成噪声指数 和级联设备的增益
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TT-LNA Example
TT-LNA 实例
Parameter
参数
dB Value
dB值
Linear Value
线性值
F1 1 dB 1.26
G1 15 dB 31.6
L2 = Lfeeder 3 dB 2
G3 = -Lfeeder -3 dB 0.5
F3 4 dB 2.51
)dB42.1(39.1
5.06.31
151.2
6.31
1226.1
eqF
d B m4.1 1 1
dB42.1d B m8.1 1 2
eqeq k T B FN
Neq is the equivalent noise at the TT-LNA input,Neq
是 TT-LNA输入的等价噪声。
The noise power at the BTS input will be (in dBm),
BTS输入的噪声功率是 (用 dBm):
NBTS =Neq +G1- L2 = -111.4 + 15 – 3 = -99.4 dBm
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TT-LNA Summary
TT-LNA 摘要
While the TT-LNA can improve the reverse link (typically by as
much as 5 dB),the forward link may become the limiting link,
在 TT-LNA可能增加反向链路 (尤其增加 5 dB)的同时，前向链路可能会成为受限链路。
To balance the links and maximise coverage,the forward link
power would need to be increased
为了均衡链路并达到最大限度的覆盖，前向链路功率需要增加。
Telstra uses this approach in Rural areas with the Nortel
“Boomer” BTS
Telstra在农村地区将此方法用于 Nortel的,Boomer”BTS。
15W? 65 W (6.4 dB)
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Part 3 Capacity
第 3 部分 容量
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Review of Erlang Theory
Erlang 理论的回顾
Poisson Arrival Process （ 泊松到达过程）
Mean Inter-arrival rate l （ 平均中间到达率 l）
Negative Exponentially distributed Hold times
负对数分布维持时间
Mean Hold time m （ 平均维持时间 m ）
Offered Erlang Load A = l/ m erlangs
提供的 Erlang 负载 A = l/ m erlangs
Probability distribution of offered number of calls,
提供的的呼叫数量的分布概率：
Given C serving channels,probability of blocking (Lost Calls
Cleared),（ 假定 C是服务信道，阻塞概率 (清除丢失呼叫 )：
mlml e
kp
k
k !
C
n
n
C
C
n
Cp
0
!/
!/
ml
ml
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Probability of Offered Calls
提供的呼叫概率
Example,（ 实例）
A = l/ m = 10 erlang
0,2
0
p k 10?( )
200 k
0 5 10 15 20
0
0,0 5
0,1
0,1 5
The number of calls in the system is a
random variable
系统中呼叫的数量是随机分布
The Normal Distribution is a useful
approximation to pk,
正态分布是 pk.的有用的近似
Mean = A,s = A
mlml e
k
p
k
k !
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TDMA/FDMA Erlang and Channel Capacity
TDMA/FDMA Erlang 和信道容量
Example （ 实例）
GSM with 4/12 reuse and 42 frequencies,
GSM 具有 4/12 重用和 42个频率
Frequencies per sector = 42/12 = 3.5
频率 \扇区 = 42/12 = 3.5
TCH Timeslots per sector = 3.5*8 –1 = 27
TCH 时隙 \扇区 = 3.5*8 –1 = 27
Channel Capacity = 27
信道容量 = 27
Erlang Capacity = ErlangB(27,2%) = 19.2 E Erlang
容量 = ErlangB(27,2%) = 19.2 E
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Forward Link Traffic Channel Capacity
前向链路业务信道容量
Forward link power is shared between
前向链路功率由以下两个共享：
Primary links （ 主链路）
Secondary links (soft and softer handoff)
第二链路 (软和更软切换 )
BTS2BTS2
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Forward Power Depends on Mobile Location前向功率依赖于移动台位置
These graphs show random mobile locations and required forward
link traffic channel power to achieve Eb/No = 10 dB at the mobile
这些图表显示的是随机的移动台的位置以及要求的前向链路业务信道功率以得到在移动台的 Eb/No = 10 dB
Wanted cell Mobile locations.
-20.00
-15.00
-10.00
-5.00
0.00
5.00
10.00
15.00
20.00
-20.00 -15.00 -10.00 -5.00 0.00 5.00 10.00 15.00 20.00
0,0 0 0
1,0 0 0
2,0 0 0
3,0 0 0
4,0 0 0
5,0 0 0
6,0 0 0
7,0 0 0
8,0 0 0
9,0 0 0
1 0,0 0 0
1
27 53 79
105 131 157 183 209 235 261 287 313 339 365 391 417 443 469 495
Sa m p l e
F
w
d
T
C
H
Po
w
e
r
(W
)
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Single Cell Simulation of Forward Power
前向功率的单个小区仿真
Cell radius = 2 km （ 小区半径 = 2 km）
Hata Suburban Model with 20 dB clutter loss,shadowing Std
Dev = 8 dB
Hata 郊区模型有 20 dB 散射损耗,阴影 Std Dev = 8 dB
MS NF = 8 dB,Eb/No = 10 dB (-116 dBm traffic channel
sensitivity)
MS NF = 8 dB,Eb/No = 10 dB (-116 dBm 业务信道灵敏度 )
Max Fwd power = 15 W,Overhead power = 25%
最大前向功率 = 15 W,开销功率 = 25%
10 Erlangs of offered traffic (no SHO)
10 Erlang 所提供的业务 (无 SHO)
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Sample Simulation Results
实例仿真结果
T o ta l T x P o w e r
0,0
5,0
1 0,0
1 5,0
0 10 20 30 40 50 60 70 80 90 100
I n s t a n c e
W
a
t
ts
T o ta l T x P o w e r
0,0
5,0
1 0,0
1 5,0
0 10 20 30 40 50 60 70 80 90 100
I n s t a n c e
W
a
t
ts
R = 2 km
R = 3 km
Total Power > MaxPwr
总功率 > 最大功率
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CDMA Channel and Traffic Capacity
CDMA 信道和业务容量
CDMA Channel Capacity is not fixed（ CDMA 信道容量不是固定的）
depends on F,VAF,Isc and Ioc
（依赖于 F,VAF,Isc 和 Ioc）
also depends on user locations and SHO
（ 也依赖于用户位置和 SHO）
CDMA has a,soft” capacity limit （ CDMA 有一个,软,容量限制）
Current practical estimates （ 当前实用的评估）
Offered Traffic at 2% Blocking
在 2%阻塞时提供的业务
Equivalent Channel Capacity
等价信道容量
IS95A,EVRC 13 E 20 channels
1xRTT EVRC 19.5 E 28 channels
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Monte Carlo Simulations 蒙特卡罗仿真
CDMA coverage and capacity depends on,
CDMA 覆盖和容量依赖于：
Mobile locations (affecting noise-rise and
forward power) 移动台的位置 (影响噪声增益和前向功率 )
Radio channels (multipath) and Mobile speed
(both affecting Eb/No) 无线信道 (多径 ) 和移动速度 (都会影响 Eb/No)
Simulation is one way of analysing the statistical nature of CDMA
coverage and capacity performance
仿真是分析 CDMA 覆盖和容量性能的统计特性的一种方式
Most CDMA planning tools include a,Monte-Carlo” tool for simulating
coverage and capacity performance
大多数 CDMA 规划工具都包括,蒙特卡罗,工具，用于进行覆盖和容量性能仿真
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Monte-Carlo Simulations
蒙特卡罗仿真
Monte-carlo simulation provides a series of
“snapshots” of N mobile locations.
蒙特卡罗仿真提供了 N个移动台位置的一连串的,快照”
Mobile profiles include Eb/No,in-building
probabilities etc,
移动台分布图包括 Eb/No,建筑物内的概率等等。
Results are stored for each,run” or,drop”.
对每个,运行,或者,掉线,结果都予以储存。
Results from K,drops” are averaged to
obtain mean and percentile values at each
grid location (eg 90th percentile for Mobile
Transmit power).
从 K 个“掉线,得到的结果经过平均得到在每一个格子位置的平均值和百分点值 (如移动台传输功率的第 90个百分点 )。
Generate random
locations for N mobiles
产生 N个移动台随机位置
Start （ 开始）
Iterate to find stable solution
for Reverse and Fwd Tx
powers
为反向和前向 Tx功率重复寻找稳定的解决方案
Traffic Density
map
业务密度图
Mobile Profiles
移动台分布图
Write Results
写结果
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Monte-Carlo Simulations
蒙特卡罗仿真
Monte-Carlo simulations require significant processing time
蒙特卡罗仿真需要相当长的处理时间
Questionable benefit for coverage designs
覆盖设计的益出让人质疑
Many inputs and assumptions required
需要很多输入和假设
Standard techniques using link budgets and power contouring are more
straight forward
采用链路预算和功率等值线的标准技术更加直接
Monte-Carlo useful for analysing,what-if” scenarios and developing
strategies to optimise capacity in problem areas
蒙特卡罗对于分析,what-if” 情况和在问题区域制定策略以优选容量很有用处
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Part 4 Search Window Design
第 4 部分 搜索窗口的设计
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The role of PN Offsets
PN 偏置的作用
IS95 is a synchronous system （ IS95 是一个同步系统）
GPS used to lock transmitted pilot signals to < 3 us of GPS (UTC) time
（ GPS 以前用于锁定传输给 < 3 us GPS (UTC) 时间的导频信号
Each Sector transmits a Pilot signal（每个扇区传输一个导频信号）
defined by a PN number,512 PNs defined in IS95,
由 PN 号码定义。 有 512 个 PN 定义在 IS95中。
1 PN = 64 chips spacing （ 码片间隔）
Allowable PNs in a system determined by PILOT_INC parameters
系统中允许的 PN是由 PILOT_INC 参数决定的
Example （ 实例）,PILOT_INC = 3。 Allowable PNs （ 允许的
PNs） = 0,2,5….
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Example 1
实例 1
3 BTS
0.75,1.5 and 3 km from
mobile 距离移动台 0.75,
1.5 和 3km
Mobile derives time from BTS-1 (strongest)
移动台以 BTS-1 时间为准 (最强的 )
Relative delay of BTS-2 （ BTS-2相对延时）
1.5 – 0.75 = 0.75 km
= 3.1 chips
Relative delay of BTS-3 （ BTS-3相对延时）
3 – 0.75 = 2.25 km
= 9.225 chips
0.75 km
1.5 km
3 km
BTS-1
BTS-3
BTS-2
1 chip = 0.814ms = 244 metres
4.1 chips per km
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Example 1 Timing Diagram
实例 1 时间表
MS Time
BTS-1
BTS-2
30
60
30 60
BTS-2
90
3.1 chips (0.75km) 6.2 chips (1.5 km)
90
12.3 chips (3 km)
Search Window
搜索窗口
Search Window
搜索窗口
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Search Window Size搜索窗口的大小
Window width too small
窗口的宽度太小
Cannot capture useful
multipath energy
不能捕获有用的多径能量
Signals outside window
contributes to Io in Ec/Io
窗口外的信号对于 Ec/Io中的 Io也起作用
Window width too large
窗口的宽度太大
Mobile search time takes
longer
移动台搜索时间会更长
During the search period
the signal may cause large
interference as it is not
added to active set yet
在搜索期内由于信号还不加到现行的设置上因此会产生大的干扰。110.4 (?55.2)45215
78.1 (?39.05)32014
55.2 (?27.6)22613
39.1 (?19.55)16012
31.7 (?15.65)13011
24.4 (?12.2)10010
19.5 (?9.75)809
14.6 (?7.3)608
9.8 (? 4.8)407
6.8 (? 3.4)286
4.9 (? 2.45)205
3.4 (? 1.7)14 4
2.4 (? 1.2)103
2.0 (? 1)82
1.5 (? 0.75)61
1.0 (? 0.5)40
Window Size
(km)
Window Size
(PN Chips)
SCHWIN
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Calculating SCHWINs
计算 SCHWINs
Soft Handoff Region
dmax = |d2 –d1|
Window size（ 窗口大小） T > 2 * (dmax/c + tmax) / Tchip chips
Where（ 其中） c = 3x108 m/s,Tc = chip interval = 0.814 ms
d1 d2
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P N O f f s e t D i s t r i b u t i o n
0
10
20
30
40
50
60
70
-2
5
-2
3
-2
1
-1
9
-1
7
-1
5
-1
3
-1
1
-9 -7 -5 -3 -1
1 3 5 7 9
11 13 15 17 19 21 23 25
C h i p O f f s e t s
B
i
n
C
o
u
n
t
Graph of PN Offset distributions
PN 偏置分布图
The plot of a PN offset distribution can assist in tuning the search window widths,These offsets are reported
in PSMMs,（ PN 偏置分布图对调节窗口的宽度有帮助。这些偏置在 PSMM中有报告。）
Window must be wide
enough to capture
useful multipaths
窗口要足够宽以捕获有用的多径
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Graph of PN Offset distributions (cont)
PN 偏置分布图 (续 )
Survey tools such as Nortel RFO can report where multipaths
(in chips) are measured,
调查工具如 Nortel RFO 可以报告在哪里测量多径 (按码片 ) 。
Histograms can also be produced from PSMM,The signal
strengths of pilots reported in PSMM are recorded in phase
offsets,eg PILOT_PN_PHASE = 7170 chips = PN112 + 2 chips,
柱状图也可以从 PSMM产生。在 PSMM中报告的导频的信号强度记录在相位偏置中，如导频 _PN_相位 = 7170 chips = PN112 + 2
chips.
From this,one can deduce that this particular multipath is 2
chips away from the centre of the search window
由此，我们可以推断这个特定的多径偏离搜索窗口中心 2个码片
。
By collecting PSMM from live traffic,one can choose the optimal
search window width for the environment being studied,
通过从活动业务中收集 PSMM,我们可以为正在研究的环境选择最佳的搜索窗口。
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Part 5 Radio Resource
Management
第 5 部分 无线资源管理
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What is Radio Resource Management?
什么是无线资源管理?
RRM is the management of the physical and logical resources
involved in setting up and maintaining a call
RRM 是对建立和维护一个呼叫所涉及的物理和逻辑资源的管理
Resources can include （ 资源可以包括）：
channel elements （ 信道单元）
power （ 功率）
Walsh codes （ Walsh 码）
RRM algorithms are required to manage,
需要用 RRM算法进行管理：
Call admission （ 呼叫接入）
Call handoff （ 呼叫切换）
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Radio Resource Management across Multiple Carriers
通过多载波的无线资源管理
IS95A is inherently different to conventional FDMA systems such as GSM
or AMPS IS95A 和传统上的
FDMA 系统如 GSM 或者 AMPS有内在的差异
There are few features to allow mobiles to search for other frequencies
（ 几乎没有特怔允许移动台搜寻其他的频率）
searching is limited to PNs on the same carrier frequency
搜索限制在位于 同一 个载波频率的 PN中
IS95B introduced a feature to allow mobiles to search PNs on other
frequencies IS95B介绍了一个特征，可以允许移动台搜索位于其他频率的 PN
Not widely used（ 没有广泛采用）
Limited support for this feature in mobiles
移动台对于这个特征的支持有限
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Idle Mode Distribution of Traffic
业务的空闲模式分配
On power up,mobiles acquire the Primary Carrier
当加电时，移动台接到主载波
Mobiles read a channel list from the system parameters
message
移动台从系统参数消息中读取信道列表
Mobiles perform a,hashing” function to determine which carrier
to select for idle mode
移动台完成,散列法,操作以确定选择哪一个载波作为空闲模式
A function of mobile MIN （ 移动台 MIN
的功能）
Mobiles retune to the calculated carrier frequency
移动台回到计算出来的载波频率上
Mobile originate calls on the selected carrier frequency
移动台在所选的载波频率发出呼叫
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Distribution of Traffic at Call Setup
呼叫建立时业务的分配
Some vendors offer Multi-carrier selection algorithms (eg Nortel MCTA)
一些供应商提供多载波选择算法 (如 Nortel MCTA)
All Mobiles idle and stay on FA1
所有的移动台空闲并保持在 FA1
Mobiles are directed to least loaded or preferred carrier at call
setup
移动台在 呼叫建立 时被转向最少负载的或者首选的载波）
Example（实例）
Mobile idles on FA1 (Channel 283 )
移动台空闲在 FA1 (信道 283)
Call set-up,Mobile directed to FA3 (Channel 242)
呼叫建立。移动台被转到 FA3 (信道 242)
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Example 1 – Pilot Beacon Hard Handoff
实例 1 – 导频标志硬切换
Mobile originates a call at A,Directed to set-up on PN40/FA2
移动台在 A开始一个呼叫 。 直接建立在 PN40/FA2
FA1
FA2
Distance（ 距离）
A
PN40 PN70PN10
B
Mobile travels to B,Reports PN70 from Pilot Beacon sector
移动台到 B。 从导频标志扇区报告 PN70
Mobile directed to hard handoff to FA1 (PN40,PN70)
移动台直接硬切换到 FA1 (PN40,PN70)
Goes directly into SHO with PN70,PN40 on FA1
在 FA1上用 PN70,PN40直接转到 SHO
Pilot Beacon
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Mode Distribution of Traffic – Call Setup
业务的业务模式分配 – 呼叫建立
Neighbour sectors can be data filled in the Pilot Data
Base as beacons,and can be used to trigger a Hard
Handoff to another carrier
相邻扇区可以在导频数据库中被数据填充作为标志，
并可以用于触发硬切换到其它载波
Dedicated Pilot Beacons can also be used
也可以使用专用导频标志
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Example 2 – RTD Hard Handoff
实例 2 – RTD 硬切换
FA1
FA2
Distanc（ 距离）PN40 PN70PN10
Some Vendors (Nortel and Ericsson) offer Round Trip Delay feature to
trigger a hard handoff
一些供应商 (Nortel和 Ericsson) 提供往复延时特性以触发一个硬切换
The handoff is initiated when the mobile exceeds a specified RTD
threshold
（ 当移动台超出指定的 RTD门限时即开始进行切换）
The RTD threshold is expressed in units of km or 1/8 chips (approx 30m)
RTD 门限是以 km或者 1/8chips (大约 30m)为单位来表示的
This has advantages as Pilot Beacon Hardware is not required on
surrounding sectors
这样就会有优势，因为在周围扇区不需要导频标志硬件 RTD threshold distance （ RTD门限距离）
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Example 2 – RTD Hard Handoff
实例 2 – RTD 硬切换
FA1
FA2
Distance（ 距离）
A
PN40 PN70PN10
B
Mobile originates at A and is directed to setup on PN40/FA2
移动台在 A开始并直接建立在 PN40/FA2
Mobile travels towards B （ 移动台移动到 B）
A RTD handoff trigger occurs when the mobile reaches B
当移动台到达 B 时 RTD 硬切换触发电路工作
The mobile is directed to handoff to FA1（ 移动台直接切换到 FA1） (PN10,
PN40 和 PN70)
handoff would be a multi-pilot handoff to PN10,PN40 and PN70
对于 PN10,PN40 和 PN70 切换将是多导频切换
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Multi-carrier Strategies
多载波策略
If one sector requires a second carrier,all sectors on the BTS require a
second carrier
如果一个扇区需要第二个载波，在 BTS 上所有扇区都需要第二个载波
RTD can be used for isolated BTS （ RTD 可以用于孤立的 BTS）
may not be reliable in small cells with multi-path
有多径的小扇区可能不可靠
Aim to spread traffic evenly across all sectors and BTS in a geographic
area
（ 旨在一个地理区域在所有扇区和 BTS 均匀地扩展业务）
all BTS in area upgraded to 2nd carrier at the same time
同一区域中所有 BTS 同时被提高到 第二个载波
use repeaters where feasible （ 在可行的地方使用中继器）
new BTS （ 新 BTS）
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Multi-Pilot Hard Handoff (MPHHO)
多导频硬切换 (MPHHO)
IS95 allows mobiles to hard-handoff to up to 6 target PNs
IS95允许移动台硬切换升至 6目标 PN
This is useful where there may be several possible targets
这在有几个可能的目标时会很有用
In Example 2 the handoff would be to PN10,PN40 and PN70
在实例 2中会切换到 PN10,PN40 和 PN70
Most vendors implement this
大部分供应商都执行此功能
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Part 5 Network
Dimensioning
第 5 部分 网络规模
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Capacity Dimensioning
容量规模
BTS
Carriers
载波
Channel Elements
信道单元
