High Speed Downlink Packet Access

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Chapter 11 ????????

• High Speed Downlink Packet Access

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????

• ???????????,????????????3G????????????????????????
  ???,???????????????????????,3GPP?Rel-5????????????
  (High Speed Downlink Packet Access,HSDPA)???,?????
  ?????WCDMA?????,?UMTS????????????14.4Mbps???????HS
  DPA????????? ?

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?? HSDPA ???????

• ??????? Node B ?????
• ??????????UE?
• ?????????????????(?????)?

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????

• HSDPA??
• HSDPA?????
• HSDPA?????(??)
• ??
• ??

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Section 11.1HSDPA?? HSDPA Concept
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HSDPA

• ????????(High Speed Downlink Packet Access,HSDPA)
  
• ?????????????
• ?? 2005 ? 3 ?? UMTS Rel-5
• ????????????
• ? WCDMA ???

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OVSF Code (1/2)

• ? UMTS ? WCDMA ?
• ???(channelization code)?????(orthogonal),???????
• ?????????????,???????????????
• ????????????(Spreading Factor,SF)?
• ????SF???,???????
• ?????????(Orthogonal Variable Spreading Factor
  code,OVSF code)

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OVSF Code (2/2)

• ?????? OVSF ?????????????????????????
• ??????OVSF??????????????????
• ??(code tree)????????????OVSF??
• ??? root ? leaf ?? path ?,??????????????

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OVSF Code Tree
Chip length SF1 SF2 SF4
SF8
SF4, 3.84Mbps/4960kbps
SF8, 3.84Mbps/8480kbps
data 0 1 code 0110 0110
data 0 code 0110 1001
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? 11-1 OVSF ?????
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???????

• ?????????????????????????(radio bearer
  service)?????????????????
• ?????
• ?????????(Physical Channel)
• MAC ??????????(Transport Channel)
• RRC ? RLC ??????(Logic Channel)

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??????????
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????

• 3GPP ???????????(transport channel)
• ????(common channel)
• ????(dedicated channel)
• ????(shared channel)
• ps ????????????????????????

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?11-1 ??????????
???? ???? ???? ???? ???? ????
???? DCH FACH RACH CPCH DSCH USCH
??/?? ?? ?? ?? ?? ?? ??(TDD)
?????? ? ? ? ? ? ?
??? ? ? ? ? ? ?
??????? ?? ? ? ? ?? ??
????????????? ? ? (??????) ? (??????) ? ? ?
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????(Common Channel)

• ?? RACH(??)? FACH(??)????????
• ??????????(setup time)???
• ??????????????,????????(???????????)?
• ???????????(open loop power control)????????,?????
  ??????????,???????
• ?????????????????

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????(Dedicated Channel)

• ?? DCH ?????
• ???????????????
• ????????????????????????
• ???????????????
• ?????????????? kbps ????? 2Mbps?
• ?????????????????

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????(Shared Channel)

• ????????????(bursty packet data)???
• ????????????????,?????????,???????????????,???????
  ??????????
• UMTS ????? DSCH ??????????,????????????????????

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HS-DSCH

• HSDPA ????????????????????
• ????????????????(High Speed Downlink Shared
  Channel,HS-DSCH)
• ????????????(High Speed Physical Downlink Shared
  Channel,HS-PDSCH)
• HSDPA ??????? UE,?????????????? UE?
• ?WCDMA R99?,???????????????????,?SF??????,????4?25
  6?????Rel-5 HSDPA?,SF?????16?

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MAC ????

• ?WCDMA??????????MAC?????????
• MAC-b??????(broadcast)?????????????????? UE ??
  MAC-b ??? Node B ?,???????MAC-b???
• MAC-d??????(dedicate)?????? UE ???? MAC-d ???
  SRNC ??????? UE ? MAC-d ???
• MAC-c/sh???????(common)???(shared)????????? UE
  ??? MAC-c/sh ??CRNC ????????????????? MAC-c/sh
  ???

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? 10-14 MAC ??
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MAC-hs

• ??? HS-DSCH,HSDPA ? Node B ???????? MAC ??,??
  MAC-hs,??????????
• ???????????????????
• ?????????(Hybrid Automatic Repeat reQuest,HARQ)
• ???????(Adaptive Modulation and Coding,AMC)?
• ?????????????(fast cell selection)?

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?????????

• ????? RNC ?? Node B ? MAC-hs ??
• Node B ????????,?????????,?????(delay)?

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???????

• ???????,???????????????,???????
• Node B ???????????????????,???????????????????????
  ?
• ?????????????????????, HSDPA ???????(Transmission
  Time Interval,TTI)? 10 ? 20ms ??? 2ms,???? TTI
  ?????????

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??????(Fast Cell Selection)

• ?????,UE ??????? Cell ??????,????????,????????????
  
• HSDPA ???????????
• UE ???? Node B ???????(common pilot
  channel)?????,??????????????,?????????UE???,??????
  ???(serving cell)?
• ???????????????????,??????????????

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? 11-2 HSDPA UTRAN ???
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Section 11.2HSDPA ????? HSDPA Physical
Architecture
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????????

• HSDPA ? UTRAN ??????????????, ?11-3?
• MAC-hs ??????? HARQ?AMC ? HS-DSCH
  ???(scheduling)?
• HS-DSCH FP(Frame Protocol)?????? SRNC ?? CRNC,??
  CRNC ?? Node B ???UE?

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? 11-3 HSDPA ??????
?????????HSDPA???????
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MAC-d ???

• MAC-hs ??? MAC-d ????
• MAC-d ???????????????DCH?DSCH ? HS-DSCH,?????RRC?
• ??? HS-DSCH ?,MAC-d ??????????????????MAC-d???????
  (Packet Data Unit,PDU)??
• SRNC MAC-d ??PDU ?? Node B??MAC-hs ???

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? 11-4 UTRAN ? MAC-d ????
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Node B ? MAC-hs ??? (1/3)

• TFRC ??
• TFRC??????????(Transport Format and Resource
  Combination)????
• TFRC ??? HS-DSCH ??????,?????????????
• ????(flow control)
• ???????? MAC-d ? PDU,??? HS-DSCH ??????????
• ????????,???????????

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Node B ? MAC-hs ??? (2/3)

• HARQ??(entity)
• ??????????HARQ???
• ?? HARQ ???????????????????????(Stop-And-Wait
  Hybrid ARQ,SAW-HARQ)??? HARQ ???
• HARQ ?????????????,????????????????(packet
  scheduler)?

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Node B ? MAC-hs ??? (3/3)

• ??/?????(scheduling/priority handling)
• ????? MAC-hs ? PDU ? Queue ID ?????(Transmission
  sequence number,TSN)?
• ?? HARQ ????????????????????????????
• ?????????(priority)???HARQ entity??? HS-DSCH
  ?????
• ???????(priority queue distribution)???? PDU
  ???????????
• ????????????(priority queue)????????????

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? 11-5 UTRAN ? MAC-hs ???
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?? HS-DSCH ????

• ???????
• ?????????? DCH ????
• ??? HS-DSCH ???????? DCH ????????
• ??? DCH ?????
• ???????????(Shared Control Channel for
  HS-DSCH,HS-SCCH)?
• ????????????(High-Speed Dedicated Physical
  Control CHannel,HS-DPCCH)?

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HS-SCCH

• ??? HS-SCCH ????? HS-DSCH ??(demodulation)???????U
  E?
• ??? HS-SCCH ???????
• ?????????????????????(?QPSK?16 QAM)?
• ??????????????Redundancy(??HARQ)?ARQ?????,????????
  ????????

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HS-DPCCH

• ??? HS-DPCCH ?????,??
• ACK/NACK???,??UE???????????(Cyclic Redundancy
  Check,CRC)??????????
• ??????(Channel Quality Indicator,CQI)?????????????
  ???????????????????
• ??????????????AMC?
• Node B ???????????????

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? 11-6 HSDPA ?????????????
?? ACK/NACK ???????,?????????AMC?
??????????
??HARQ?Redundancy?ARQ????????????????
???????????????
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HS-DSCH ???

• PDU????????????HS-DSCH??????????????????
• ?? 11-7?

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? 11-7 ?? HS-DSCH ??????????????
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Section 11.3HSDPA????? HSDPA New Technologies
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Section 11.4??Summary
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Summary

• ????????????,3GPP?Rel-5????HSDPA?????????HSDPA???,
  ????????????????HSDPA????HS-DSCH?,????????????????
  ????????HSDPA????????Node B??,??????????,?????????
  ??14.4Mbps,?????????????UMTS??????????HSDPA?????,?
  ???????

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Homework