Post on 16-Dec-2015
description
MobileComm Professionals, Inc.
Your Partner for Wireless Engineering Solutions
High Speed Packet Access
MobileComm Professionals, Inc.
HSPA
HSUPA
HSDPA
Agenda
MobileComm Professionals, Inc. HSPA Evolution
HSPA has improved performance and spectral efficiency in DL and UL by introducing a shared channel principle: Significant enhancement with peak rates up to 14.4 Mbps in DL Huge capacity increase per site; no site pre-planning necessary Improved end user experience: reduced delay/latency, high response time
Introduced by 3GPP in Dec. 99, WCDMA Based Tech., Matured GSM/GPRS CN, up to 384 kbps (2Mbps)
Rel.99 Rel. 4 Rel. 5 Rel. 6
Bearer independent CS Core Network, CAMEL Phase 4, low chip rate TDD mode, UTRA FDD Repeater .
HSDPA (14 Mbps), IMS phase 1, W-AMR, Location Services, 1800/1900 MHz
HSUPA (5.76 Mbps), IMS Phase 2, MMS enhancement, MBMS, WLAN-Internetworking
MobileComm Professionals, Inc.
Peak data rates of HSDPA increased to significantly higher than 2 Mbps; Theoretically exceeding 10 Mbps.
Packet data throughput increased 50-100% compared to 3GPP release 4
Reduced delay from retransmissions.
Solutions
Adaptive Modulation and Coding
Layer1 hybrid ARQ
Short frame2 ms
Schedule in 3GPP
Part of Release 5
First specifications version completed 03/02
HSDPA Features
MobileComm Professionals, Inc. HSDPA Principle
Fast Hybrid ARQ with Soft Combining
Reduced round trip delay
Fast Link Adaptation
Data rate adapted to radio conditions on 2 ms time basis
t
P
Dynamic Power Allocation
Efficient power & spectrum utilisation
Higher-order Modulation
16QAM in complement to QPSK for higher peak bit rates
HSDPA
Shared Channel Transmission
Dynamically shared in time & code domain
MobileComm Professionals, Inc. Hybrid Automatic Repeat Request
Server RNC Node-B
UE
RLC retransmissions
TCP retransmissions
H-ARQ: MAC-hs Layer-1
retransmissions
Round-Trip Time: 16 ms
HARQ
MobileComm Professionals, Inc. Dynamic Power Allocation
3GPP Release 99 3GPP Release 5
Dedicated channels (power controlled)
Common channels
Power usage with dedicated channels
t
Unused power
Power
To
tal
ce
ll p
ow
er
Dedicated channels (power controlled)
Common channels
Power usage with dedicated channels
t
Used for HSDPA
Power
To
tal
ce
ll p
ow
er
MobileComm Professionals, Inc. Adaptive Modulation & Coding (1/3)
HSDPA uses: QPSK 16QAM Dynamically based on quality of the radio link
MobileComm Professionals, Inc. Adaptive Modulation & Coding (2/3)
MobileComm Professionals, Inc.
HSDPA adapts the Modulation to the current Radio Link Quality (Ec/Io) HSDPA uses: QPSK at low Radio Link Quality 16QAM at high Radio Link Quality
HSDPA adapts the Coding to the current Radio Link Quality (Ec/Io) HSDPA varies the Coding between 1/4 3/4 (theoretically 1/6 0.98)
Adaptive Modulation & Coding (3/3)
MobileComm Professionals, Inc. Fast Link Adaptation
WCDMA used Power control to compensate for differences and variations in radio channel conditions.
So available o/p power was not fully used as power needed to be reserved for ongoing connections.
Surplus of o/p power cannot be used to increase the throughput of the system. HSDPA - Relies on bit-rate adjustment (known as Link Adaptation)
High data rate
Low data rate
Fast Radio Channel Dependent Scheduling
Scheduling of users on 2 ms time basis
2 ms
Short TTI (2 ms)
Reduced round trip delay
MobileComm Professionals, Inc. Scheduling
Fast Scheduling in the Time domain (2): - Transmission is based on:
Channel Quality, UE Capabilities Current load in the cell (available resources / buffer status) Traffic Priority classes / QoS classes UE Feedback (ACK/NACK)
Fast Scheduling in the code Domain - Up to 15 codes in parallel per TTI
MobileComm Professionals, Inc. Shared Channel Transmission
Channelization codes allocated
for HS-DSCH transmission
5 codes (example)
SF=16
SF=8
SF=4
SF=2
SF=1
User #1 User #2 User #3 User #4
TTI
Shared
channelization
codes
MobileComm Professionals, Inc.
Multi Code Operation
C1,0 = [1]
C2,1 = [1-1]
C2,0 = [11]
C4,0 = [1111]
C4,1 = [11-1-1]
C4,2 = [1-11-1]
C4,3 = [1-1-11]
C8,1 = [1111-1-1-1-1]
C8,2 = [11-1-111-1-1]
C8,3 = [11-1-1-1-111]
C8,4 = [1-11-11-11-1]
C8,5 = [1-11-1-11-11]
C8,6 = [1-1-111-1-11]
C8,7 = [1-1-11-111-1]
C16,1 =
[.........]
C16,15 =
[........]
C16,14 =
[........]
C16,13 =
[........]
C16,12 =
[........]
C16,11 = [........]
C16,10 =
[........]
C16,9 =
[.........]
C16,8 =
[.........]
C16,7=
[.........]
C16,6 =
[.........]
C16,5 =
[.........]
C16,4 =
[.........]
C16,3 =
[.........]
C16,2 =
[.........]
C8,0 = [11111111] C16,0 =
[.........]
SF = 1 2 4 8 SF = 16 256 512 ...
Shared Channel Transmission
MobileComm Professionals, Inc.
Peak data rates increased to significantly higher than 2 Mbps; Theoretically reaching 5.8 Mbps
Packet data throughput increased, though not quite high numbers expected as with HSDPA
Reduced delay from retransmissions.
Solutions Layer1 hybrid-ARQ Node B based scheduling for uplink Frame sizes 2ms & 10ms
Schedule in 3GPP Part of Release 6
HSUPA Features
MobileComm Professionals, Inc.
HSUPA
Fast Power Control
Hybrid ARQ with incr.
redundancy NodeB Controlled
Scheduling
Shorter TTI [TTI = 10 ms or 2 ms]
HSUPA Principles
MobileComm Professionals, Inc. Shorter Transmission Time Interval
10 ms TTI:
Improved cell edge
performance
2 ms TTI:
reduced latency
higher peak rates
(up to 5.8 Mbps)
The use of a shorter TTI within 3G HSPA reduces the round trip time and enables improvements in adapting to fast channel variations and provides for reductions in latency.
MobileComm Professionals, Inc. Node B Controlled Scheduling
R6 E-DCH
Data
transmission
L3 Resource
Allocation
Scheduling Info
Scheduling
Assignment
DCH services
(eg voice and visio)
UE 2
UE 1
UE 1
UE 2
UE 3
UE 1
UE 2
UE 3
UE 1
TTI 0 TTI 1 TTI 2 TTI 3
RoT
Time
Maximum
allowable
noise rise
MobileComm Professionals, Inc. H-ARQ
HARQ Mechanism
The Stop and Wait (SAW) protocol for multi-channel or multi-process is performed through four (TTI=10 ms) or eight (TTI=2 ms) processes.
Each Radio Link (RL) sends the feedback respectively. Each RL establishes one E-HICH. The E-HICH information sent by each Radio Links set (RLs) is the same and can be combined. If any E-HICHs return ACK, then the transmission succeeds
For Fast retransmissions
MobileComm Professionals, Inc. HSDPA
SINR is used instead of Eb/No in HSDPA performance evaluation
Modulation and coding Bit rate can be changed every 2 ms
Definition of HS-DSCH SINR:
Narrowband signal-to-interference-plus-noise-ratio after
despreading of the HS-PDSCH
SINR includes the SF16 processing gain for the HS-PDSCH and the
effect of using orthogonal codes
Average HS-DSCH SINR:
This is the experienced HS-DSCH SINR by a user average over fast
fading.
MobileComm Professionals, Inc. Required SINR
PDSCHHSSFI
CSINR
NothownDL PIII )1(
Where: C = received power Iown = total power received from the serving cell Ioth = total power received from other cells PN = noise power = orthogonality factor SFHS-PDSCH = Spreading factor on HSDPA (= 16)
MobileComm Professionals, Inc. Channels Needed for HSDPA Operation
Iub
Node B RNC
MobileComm Professionals, Inc.
UE
Iub Uu
Node B RNC
Channels Needed for HSUPA Operation
MobileComm Professionals, Inc.
HSPA
HSUPA
HSDPA
Summary
MobileComm Professionals, Inc.
HAPPY LEARNING
MobileComm Professionals, Inc. www.mcpsinc.com