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Overview. Why HSDPA?HSDPA FeaturesHybrid Automatic Repeat Request Fast cell site selection Adaptive Modulation and CodingHSDPA TerminalsHSDPA evolutionConclusion. Why HSDPA?. Increasing bit rates in downlink.Reducing delay "TTI".Efficient users scheduling.Simultaneaous single carrier support for UMTS and R5 HSDPA.
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1. 3.5G(HSDPA) High Speed Downlink Packet Access
By
Ahmed Al-khaldi
Ali bader Al-shaei
Hassan Al-hassan
2. Overview Why HSDPA?
HSDPA Features
Hybrid Automatic Repeat Request
Fast cell site selection
Adaptive Modulation and Coding
HSDPA Terminals
HSDPA evolution
Conclusion
3. Why HSDPA? Increasing bit rates in downlink.
Reducing delay ”TTI”.
Efficient users scheduling.
Simultaneaous single carrier support for UMTS and R5 HSDPA
4. Why HSDPA? Comparison Between 3G & 3.5G.
Data Rate ( 2Mbps -----> 10 Mbps)
Modulation ( QPSK -----> QPSK&16QAM)
TTI( 10ms ----> 2ms )
5. How HSDPA ? HSDPA Features Decreasing delay due to transmission errors
Hybrid Automatic Repeat Request
6. H-ARQ Schemes Chase combining
Incremental Redundancy
7. Chase Combining Coding is applied to transmission packets
Soft combining of original and retransmitted signals is done at receiver before decoding
Advantage:
self decodable, time diversity, path diversity
Disadvantage:
wastage of bandwidth
8. Incremental Redundancy Advantage:
Reducing the effective data throughput/bandwidth of a user and using this for another user
Disadvantage:
non-self decodable
9. How HSDPA ? HSDPA Features Decreasing delay due to transmission errors
Hybrid Automatic Repeat Request
Decreasing HO failure
Fast cell site selection
10. Fast cell site selection (FCS) 20 to 30% of UE on soft handover
Tracking of active set of Node B‘s connected to a UE
Selection of the Node-B with the best current transmission characteristics
High data rates can be achieved
11. Additional Physical Channels High Speed Physical Downlink Shared Channel (HS-PDSCH)
HS-Downlink Shared Channel (HS-DSCH)
HS-Shared Control Channel (HS-SCCH)
High Speed Dedicated Physical Control Channel (HS-DPCCH)
12. How HSDPA ? HSDPA Features Decreasing delay due to transmission errors
Hybrid Automatic Repeat Request
Decreasing HO failure
Fast cell site selection
Improving resources management
Stand alone downlink shared channel
Adapting to environment local features
Adaptive Modulation and Coding
13. AMC Modulation Schemes:
QPSK
16QAM
Code Rates used:
1/4, 1/2, 5/8 and ¾
14. HSDPA EVOLUTION
15. HSDPA Terminals New terminals are required to take advantage of HSDPA:
PC-cards will be the first on the market
In the 1st phase terminals will offer:
Download 3,6 Mbps end user throughput
Upload 384 kbps
Hand-held terminals will follow
In a 2nd phase, peak data rates are increased to:
Download 14 Mbps
Upload 384 kbps
16. Conclusion The most changing from 3G to the 3.5G is the modulation.
More efficient implementation of interactive and background Quality of Service (QoS) classes
Peak data rates exceeding 2 Mbps and theoretically 10 Mbps & more with MIMO
17. Any questions ?