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3.5G-High Speed Downlink Packet Access(HSDPA) Under the Guidance of Dr.T.Kishore Kumar Associate Professor SEMINAR By K.Vamsi Krishna Roll no:EC09425
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INTRODUCTION WHAT IS HSPDA ? EVOLUTION OF HSDPA PROPERITES OF HSDPA FEATURES OF HSDPA COMPARISON WITH 1XEV/DO HSDPA CHANNELS CONCLUSION REFERENCES
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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
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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
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drivers are capacity, data speeds, lower cost of delivery for revenue growth
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Shared-channel transmission A shorter Transmission Time Interval (TTI) Link adaptation Fast scheduling Fast retransmission and soft-combining 16-QAM and 64-QAM (Quadrature Ampliotude Modulation) MIMO
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Shared Channel Transmission In Release 5, up to 15 codes (SF16) can be allocated and shared between the users. It also depends on what the UE can support. Channelization codes allocated for HS-DSCH transmission 5 codes (example) SF=16 SF=8 SF=4 SF=2 SF=1 User #1User #2User #3User #4 TTI Shared channelization codes A set of radio resources dynamically shared among multiple users, primarily in the time domain
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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
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Fast Link Adaptation ◦ Adjusts data rate based on the Radio conditions (CQI) ◦ Fast Adaptation : 2 ms TTI basis ◦ Adaptive Modulation (QPSK and 16 QAM) and Coding High data rate Low data rate HS-DSCH with dynamic power allocation t Dedicated channels (power controlled) Common channels HS-DSCH (rate controlled) Total cell power Power
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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
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Fast Channel-dependent Scheduling (MAC-hs) Scheduling => which UE to transmit to at a given time instant and at what rate ◦ MAC-hs (a new MAC sub-layer in RBS) Basic idea: transmit at fading peaks ◦ May lead to large variations in data rate between users high data rate low data rate Time #2#1#2 #1 User 2 User 1 Schedule d user
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High speed Capacity increases Reduced delay Network coverage Improved end user quality Improved overall efficiency while interacting with higher-layer protocols Deployed in both frequency division duplex (FDD) and time division duplex (TDD) in both low and high chip rates
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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
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Technical FeaturesHSDPA1xEV/DO Downlink frame size2ms TTI1,2,5,10,25ms variable frame size Channel FeedbackChannel Quality reported at 2ms or 500Hz C/I feedback at 800Hz or 1.25ms Data user Multiplexing TDM/CDM QPSK and16-QAM TDM/CDM PSK, 8 PSK, 16 QAM Hybrid ARQChase or Incremental Redundancy Asynchronous Redundancy Spreading FactorSF=16Wash code length 32 Control ChannelDedicated Channel pointing to shared channel Common Control Channel
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HSDPA Channel Structure R5 of 3GPP standard introduces 3 new channels that support HSDPA.
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One HS-DSCH (High Speed Downlink Shared Channel) Mapped to up to 15 (5 in R4, 15 in R5) HS- PDSCH Dynamic allocation every 2 msec Time sharing only in R4. Code sharing in R5. ◦ One HS-SCCH (High Speed Shared Control Channel) Control information (UE ID, HARQ, TFRC) SF 128, 2msec, downlink ◦ One HS-DPCCH (High Speed Dedicated Physical Control Channel) per UE in the uplink HARQ UL (ACK, NACK), CQI
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Also known as ‘Mobile Broadband everywhere’ ‘MAGIC’ ◦ Mobile Multimedia Communication ◦ Anywhere, Anytime with Anyone ◦ Global Mobility Support ◦ Integrated Wireless Solution ◦ Customized Personal Service
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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
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[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.umtsworld.com/technology/hspd a.htm [4]Wikipedia website: www.wikipedia.org
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THANK YOU
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