DPCH V
Vs CPICH
Nokia
T-Mobile
T
Mobile FSC
UMTS Performance Team
Power Control Related Parameter Setting-Nokia
Test case
PtxPrimary
CPICH
PtxDPCHmax
Ptx_AMR
limit1
CPICHtoRefRAB
offset
Ptx AMR
limit2
Ptx AMR
limit
=PAPtxDPCHmax
dBm
dB
dBm
dB
dBm
dBm
Reference Drive
35
-3
43
2
33
33
Test 1
35
-3
43
10
25
25
Test 2
35
0
46
2
33
33
T t3
Test
35
-3
3
43
-10
10
45
45
Test 4
35
0
46
-10
45
45
39
1
47
-6
45
45
32
-3
3
43
1
31
31
Test 5
Test6
DL power setting:
Parameters Setting-Nokia
Total PA power – 40W (No related Nokia Parameter)
CPICH power (PtxPrimaryCPICH)=35dBm
DL Maximum Tx power per traffic channel (PtxDPCHmax) = -3dB
DL Minimum
Mi i
Tx
T power per traffic
t ffi channel
h
l (Pt
(PtxDPCHmin)
DPCH i ) = -28dB
28dB
DL maximum Tx power per radio link (PtxDLabsMax) =37dBm
BLER target (DLreferenceTargetBLER) =-2.2
=10^(-2.2)=0.63% (defined in WCEL parameter)
=10^(-2)=1% (viewed from field measurement)
Downlink bit rate of the reference service (DLreferenceBitRate)=12.2 (kbps, AMR voice)
DL maximum power of reference service (CPICHtoRefRABoffset)
=2dB (= PtxPrimaryCPICH-2=33dBm)
((The parameter
p
CPICHToRefRABOffset defines the maximum link transmission power for a selected reference radio access
bearer, for example, 12.2-kbps speech service, The maximum link powers of other services are obtained by
scaling the reference maximum power with the ratio of bit rates, R/Rref, and the ratio of DL Eb/N0
requirements, /ref, between the reference and a particular service:
CPICH RSCP vs. CPICH Ec/No
RSCP
Ec/No
 Below -110.00
 >= -110.00 to < -90.00
 Above -90.00
11/08/06
Serving cell
 Below -15.0
 >= -15.0 to < -12.0
 Above -12.0
4
BLER and UE Transmit Power
BLER
UE Transmit Power




11/08/06
>= 0.00 to < 1.00
>= 1.00 to < 2.00
>= 2.00 to < 5.00
>= 5.00 to < 101.00
 Below 10.0
>=
 10.0 to < 15.0
Above
15.0

5
Effect of CPICHtoRefRABoffset on
coverage and BLER
Test case
PtxPrimary
CPICH
PtxDPCHmax
Ptx_AMR
limit1
CPICHtoRefRAB
offset
Ptx AMR
limit2
Ptx AMR
limit
=PAPtxDPCHmax
11/08/06
dBm
dB
dBm
dB
dBm
dBm
Test 2
35
0
46
2
33
33
Test 4
35
0
46
-10
45
45
6
Effect of CPICHtoRefRABoffset on
coverage and BLER
Test-Case-2 vs. Test Case-4
•
11/08/06
As can be seen,
seen increasing the
max DL transmission power of
reference service (AMR Speech)
increases the coverage along with
a reduction in the BLER even with
the same CPICH value.
7
Test 2
Effect of
CPICHtoRefRABoffset on
g and BLER
coverage
•
When the max DL transmission
power of reference service
(AMR speech) increases, the
cell coverage
g extended even
though the CPICH is the same
11/08/06
Test 4
8
Test 2
Effect of
CPICHtoRefRABoffset on
g and BLER
coverage
•
When more power is available,
more power will be consumed
Test 4
11/08/06
9
Effect of CPICHtoRefRABoffset on
coverage and BLER
Test case
PtxPrimary
CPICH
PtxDPCHmax
Ptx_AMR
limit1
CPICHtoRefRAB
offset
Ptx AMR
limit2
Ptx AMR
limit
=PAPtxDPCHmax
dBm
dB
dBm
dB
dBm
dBm
Reference Drive
35
-3
43
2
33
33
Test 1
35
-3
43
10
25
25
11/08/06
10
Effect of CPICHtoRefRABoffset on
coverage and BLER
11/08/06
11
Reference
Effect of
CPICHtoRefRABoffset on
coverage and BLER
•
In line with our previous slide the
coverage
co
e age dec
decreases
eases with
t a
decrease in the max DL Tx power
(AMR Speech) for the same value
of CPICH.
11/08/06
Test 1
12
Impact
p
of decreasing
g the CPICH
Test case
PtxPrimary
CPICH
PtxDPCHmax
Ptx_AMR
limit1
CPICHtoRefRAB
offset
Ptx AMR
limit2
Ptx AMR
limit
=PAPtxDPCHmax
dBm
dB
dBm
dB
dBm
dBm
Reference Drive
35
-3
43
2
33
33
Test6
32
-3
43
1
31
31
11/08/06
13
Reference
Impact of decreasing the CPICH
Test6 shows lower measured Ec/Io with
3dB lower on CPICH power.
11/08/06
Test6
14
Impact of decreasing the CPICH
The cell coverage breaks at similar range
regardless the difference of CPICH power
11/08/06
15
Impact of decreasing the
CPICH
DCH power limit plays significant role
in defining cell coverage
11/08/06
16
Impact
p
of increasing
g CPICH on coverage
g and BLER
Test case
PtxPrimary
CPICH
PtxDPCHmax
Ptx_AMR
limit1
CPICHtoRefRAB
offset
Ptx AMR
limit2
Ptx AMR
limit
=PAPtxDPCHmax
Test 4
Test 5
11/08/06
dBm
dB
dBm
dB
dBm
dBm
35
0
46
-10
45
45
39
1
47
-6
45
45
17
Impact of increasing CPICH on
coverage and BLER
11/08/06
18
Impact of increasing
CPICH on coverage and
BLER
•
3-4dB improvements are
measured at cell edge for test5
11/08/06
19
Impact of increasing
CPICH on coverage and
BLER
•
With 4dB higher CPICH power of
test5, no significant improvement
on cell coverage is measured
11/08/06
20
Observation from the DT data
•
Increasing the DL DCH value keeping the CPICH power constant will
improve cell coverage
•
Decreasing in CPICH with lowered DL DCH power, cell coverage change is
minim m
minimum.
•
DCH power plays more important role in defining cell coverage than CPICH
power
11/08/06
21