13-06-2014, 10:20 AM
3.5G-High Speed Downlink Packet Access(HSDPA) seminar
3.5G-High Speed Downlink.pptx (Size: 1.33 MB / Downloads: 23)
[/b] INTRODUCTION
Urge to improve the packet data capabilities of WCDMA
Growing interest towards rich calls, mobile-TV and music streaming in the wireless domain
Competitive technologies such as WIMAX
first downlink counterpart of the evolution called High Speed Downlink Packet Access (HSDPA) in Release 5
High-Speed Downlink Packet Access (HSDPA) is an enhanced 3G (third generation) mobile telephony communications protocol ie an UMTS packet air interface (adds-on solution on top of 3GPP R99/R4 in the High-Speed Packet Access (HSPA) family, also dubbed 3.5G, 3G+ or turbo 3G
[b] CQI – Channel Quality Indicator
UE sends CQI info in the UL to aid rate adaptation and scheduling
CQI (1-30) provides the Node B with a measure of the UE's perceived channel quality and the UE receiver performance
The CQI report estimates the number of bits that can be transmitted to the UE using a certain assumed power with a block error rate of 10%
UE assumes a HS- PDSCH power to calculate CQI
Fast Hybrid ARQ with Soft Combining
Rapid retransmissions of erroneous data
Hybrid ARQ protocol terminated in Node B short RTT (typical example: 12 ms)
Soft combining in UE of multiple transmission attempts reduced error rates for retransmissions
FEATURES OF HSPDA
Improving Resource management due to innovative addition of the transport channel - High Speed Downlink Shared Channel (HS-DSCH).
Adapting to environment
Adaptive Modulation and Coding –performance matched to user ‘s priority and operating environment
Fast Scheduling
Channel Quality Feedback
Decreasing Hand Off failure
REFERENCES:
[1] H.Holma and A.Toskala.”WCDMA for UMTS”, Radio Access for Third Generation Mobile Communications; Chapter 11 High-Speed Downlink Packet Access
[2] Christopher Brunner, Kevia Murray “WCDMA(UMTS) Deployment Book ,Chapter 7
[3]HSPDA in WCDMA, http://www.umtsworldtechnology/hspda.htm
[4]Wikipedia website: www.wikipedia.org
CONCLUSION:
High Speed Downlink Packet Access (HSPDA) is a concept within WCDMA specifications whose main target is to increase user peak data rates and quality of service, and to generally improve spectral efficiency for downlink asymmetrical and packet data services. It will provide a ubiquitous access to Wi-Fi applications without any constraint of hot spots and provide seamless access to every type of broadband service
that is already used