UMTS CH 7 communication discretion umt and data database.ppt

Wireless Communications Presentation by Eng. Walid Al-Safouri

Wireless Communications Presentation by Eng. Walid Al-Safouri

Wireless Communications Presentation by Eng. Walid Al-Safouri
Wireless Communications Presentation by Eng. Walid Al-Safouri
Wireless Communications Presentation by Eng. Walid Al-Safouri
Wireless Communications Presentation by Eng. Walid Al-Safouri
Wireless Communications Presentation by Eng. Walid Al-Safouri
Wireless Communications Presentation by Eng. Walid Al-Safouri
Wireless Communications Presentation by Eng. Walid Al-Safouri
Wireless Communications Presentation by Eng. Walid Al-Safouri

1. 1
By Eng. By Eng.
WALEED EL SAFOURYWALEED EL SAFOURY

2. 3G-324M over TD-SCDMA for Handsets2
Power control principle
Fast power control is essential in CDMA systems because of:
*The same frequency band and as the same frequency can be used in
principle in Each cell (re-use = 1)
*level of the (inter- and intra-cell) interferences
*The power control is also used to solve the so-called "near-far" problem
*UL power control reduces the interference between different UE, DL power
control the interference between neighboring base stations, BTS.

3. 3G-324M over TD-SCDMA for Handsets3
S/N > (S/N)
def
 TPC = Down
else TPC = Up DL:
Inner Loop PC
P(BTS)  UE TPC
UL:
• Inner Loop PC
P(UE)  BTS TPC
• Open Loop PC
P(UE)  oriented at
BTS DL Power;
for initial transmission
UTRA
Power Control
PC - Types:
• Open Loop PC
• Inner Loop PC
• Outer Loop PC
BTS
(Node B)
PC: Power Control
TPC: Transmit Power Control
S/N: Signal to Noise
UE
RNC
Outer Loop PC:
(C/I)
def
variation, to
guarantee QoS (BER,..)

4. 3G-324M over TD-SCDMA for Handsets4
• FDD: 1500 PC cycles/s
TDD: 100 - 800 cycles/s
(100/s: per frame; >100/s:
depends on frame configuration)
UE
max. power (4 classes):
• FDD: 2000 / 500 / 250 / 125 mW
• TDD: 1000 / 250 / 125 / 10* mW
PC steps: 1, 2, 3 dB
min. power: 0,04 W
Receiver Sensitivity: -110 dBm
UTRA
Power Control
BTS
max. power:
vendor specific
PC steps:
1, 2, 3 dB
Dynamic:
30 dB (= 1000)
 UTRA Capacity
Interference limited
 system stability
TPC: Transmit Power Control
* for unlicensed operation
Fast
Power Control

5. 3G-324M over TD-SCDMA for Handsets5
RAKE
Receiver
Path 1
(d
1
,a
1
)
Path 2 (d
2
, a
2
)
Path 3 (d
3
, a
3
)
d: delay
a: attenuation
RAKE Receiver:
several „finger“ for multipath components
De-
Spreading
Code (t-d
1
)„Finger 1“
De-
Spreading
Code (t-d
2
)„Finger 2“
De-
Spreading
Code (t-d
3
)„Finger 3“

a
1
a
2
a
3
Maximum
Ratio
Combining
RAKE finger:
• Despreading ( MF-Info!)
• Phase correction
• „Delay“ correction
Matched Filter MF:
measures „Pilot“
 „Delay“ estimation
Fig. 6 (TM2201EU04TM_0002 UTRA Aspects, 13)

6. 3G-324M over TD-SCDMA for Handsets6
MultiUser
Detection MUD
BTS
(Node B)
UE 1:
Code 1
UE 2:
Code 2
UE n:
Code n
Node B
De-
Spreading
Code 1
De-
Spreading
Code 2
De-
Spreading
Code n
M
u
l
t
i
U
s
e
r

D
e
t
e
c
t
i
o
n

M
U
D

&
I
n
t
e
r
f
e
r
e
n
c
e

C
a
n
c
e
l
l
a
t
i
o
n

I
C
Data 1
Data 2
Data n
MUD:
• mainly for UL (in Node B)
• reduces Intra-Cell interferences
 increases capacity
• reduces Near-Far problem

7. 3G-324M over TD-SCDMA for Handsets7
UTRA handover
The UE and BTS determine the quality and strength of a radio
transmission. The UE also determines the signal strength and
quality of its own and the local BTS's
The measurement values are compiled in a measurement report
for use by the RNC as a basis for deciding for or against
handover

8. 3G-324M over TD-SCDMA for Handsets8
Handover
UTRA Aspects
Measurement:
Connection quality & strength
+ strength of own & surrounding BTS
UE
Measurement:
Connection quality & strength
BTS
Measurement Report
RNC
HOV
Decision
Pre-processing of measurements
Activation of new BTS
„Active Set“ Update
Measurement
Report
UMTS Handover
• decision similar GSM
• initiated by RNC
• performed by UE
Fig. 8 (TM2201EU04TM_0002 UTRA Aspects, 17)

9. 3G-324M over TD-SCDMA for Handsets9

10. 3G-324M over TD-SCDMA for Handsets10
Hard Handover
UL
DL
UL
DL
DL
Soft Handover
Hard & Soft Handover

11. 3G-324M over TD-SCDMA for Handsets11
Sector cells
Soft / Softer Handover
Node B
Node B
RNC
Node B
CN
Combining /
Splitting
Active
Set
Node B
Soft Handover Softer Handover
RNC
• between sector cells
• Combining via RAKE
• Node B internal
Iu
Iub
Iub
Iub
Active Set:
max. 3 Cells

12. 3G-324M over TD-SCDMA for Handsets12
Soft Handover
Node B
Node B
RNC
Node B
CN
Combining /
Splitting
Active
Set
Inter-RNC HoV
Iu
Iub
Iub
Iub
RNC
Iur
• S-RNC: Combining/Splitting + RR allocation
• D-RNC: only RR allocation
• change D-RNC  S-RNC possible
S-RNC: Serving RNC
D-RNC: Drift RNC
RR: Radio Resource

13. 3G-324M over TD-SCDMA for Handsets13
Location servicesLocation services
• Cell coverage based
• Observed time deference of arrival
• Hearability (idle BTS time )
• Not accurate
• Assisted GPS

14. 3G-324M over TD-SCDMA for Handsets14
GPSGPS
• 24 sat
• 20200 KM