Content for TR 25.709 Word version: 15.0.0
0 Introduction
1 Scope
2 References
3 Definitions, symbols and abbreviations
3.1 Definitions
3.2 Symbols
3.3 Abbreviations
4 Objectives
...
...
0 Introduction p. 4
The HS-SCCH is a downlink control channel used for scheduling HS-DSCH transmissions as well as for instructing the UE to perform specific actions via HS-SCCH orders.
The HS-SCCH is a downlink control channel that is monitored by the UE at all path-loss conditions within the cell. According to current observations the HS-SCCH can become limiting and costly in bad radio conditions since the power invested in the HS-SCCH limits the available power for the HS-PDSCH.
The decoding of the HS-SCCH is performed by testing against all the codewords that can be carried over the HS-SCCH since any of those codewords could have been transmitted in downlink. Nonetheless an important aspect to consider is that under bad radio conditions only a small subset of the codewords carried over the HS-SCCH can occur in practice.
This is something that can be considered to enhance and simplify the decoding of the HS-SCCH channel.
1 Scope p. 5
The present document refers to a study on a simplified HS-SCCH for UMTS, which is aimed at simplifying the decoding of the HS-SCCH Type 1 for UEs undergoing bad radio conditions.
2 References p. 5
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
[1]
TR 21.905: "Vocabulary for 3GPP Specifications".
[2]
3GPP RP-170725: "Study on a simplified HS-SCCH for UMTS"
[3]
RP-170725, Study on a simplified HS-SCCH for UMTS
[4]
TS 25.212: "Multiplexing and channel coding (FDD)", version 13.0.0, Rel-13.
[5]
R1-1705866, "A Background on the structure of the HS-SCCH", RAN1 #88bis, Ericsson.
[6]
R1-1705867, "On a simplified HS-SCCH Type 1 for providing an easier decoding", RAN1 #88bis, Ericsson.
[7]
R1-1705868, "Performance evaluation of a simplified HS-SCCH Type 1", RAN1 #88bis, Ericsson.
[8]
R1-1705869, Legacy CQI reports as triggering mechanism for the simplified HS-SCCH Type 1, RAN1.
[9]
TR 25.942: V13.0.0 Radio Frequency (RF) system scenarios (Release 13)
[10]
TR 25.707: V14.0.0 Multi-Carrier Enhancements for UMTS (Release 14)
[11]
WCDMA FOR UMTS - HSPA Evolution and LTE, Fifth Edition, Harri Holma and Antti Toskala.
[12]
TS 25.214: V14.0.0 Physical layer procedures (FDD)
[13]
R1-1706210, 25.cde v0.0.1 (Skeleton) Study on a simplified HS-SCCH for UMTS", TSG RAN WG1, RAN 1 #88bis.
[14]
R1-1708732, "Full performance evaluation (HS-SCCH part I & II) of the simplified HS-SCCH Type 1 versus the legacy HS-SCCH Type 1", RAN1 #89, Ericsson.
[15]
R1-17008733, "Timing for receiving the simplified HS-SCCH Type 1 when the legacy CQI reports are used as triggering mechanism", RAN1 #89, Ericsson.
[16]
R1-1708735, "On the conclusion for the study item on a simplified HS-SCCH for UMTS" RAN1 #89, Ericsson.
[17]
R2-1705947, "TP on RAN2 impacts of simplified HS-SCCH", RAN2 #98, Ericsson.
3 Definitions, symbols and abbreviations p. 6
3.1 Definitions p. 6
For the purposes of the present document, the terms and definitions given in TR 21.905 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905.
3.2 Symbols p. 6
For the purposes of the present document, the following symbols apply:
3.3 Abbreviations p. 6
For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.
CCS
Channelization Code Set
CGI
Code Group Indicator
DL
Downlink
L1
Layer 1
MS
Modulation Scheme
4 Objectives p. 6
The objectives of this SI are [2]:
- Study the feasibility and benefits of introducing a simplified version of the HS-SCCH Type1 where some of the control information bits carried on the HS-SCCH part I are made deterministic (e.g., CCS bits and MS bit). The following aspects shall be taken into consideration:
- The L1 processing chain as described in the current UMTS standard shall be reused and no changes are allowed (i.e., adding/removing blocks to the L1 processing chain is not allowed).
- Keep backward compatibility (e.g., re-ordering bits within a slot, or from one to another slot is not allowed).
- Study mechanisms for triggering the usage of a simplified version of the HS-SCCH Type 1, if possible by making use of legacy mechanisms.
