TS C106 V2.0.0 (1999-10)
Technical Specification
China Wireless Telecommunication Standard (CWTS);
Working Group 1 (WG1);
Physical layer - Measurements (TD-SCDMA)
CWTS
Physical layer – Measurements (TD-SCDMA)
2
Contents
1 FOREWORD ................................................................................................................................................................. 4
2 SCOPE ............................................................................................................................................................................ 4
3 REFERENCES .............................................................................................................................................................. 4
4 MEASUREMENTS IN IDLE MODE .......................................................................................................................... 5
4.1 MEASUREMENTS FOR CELL SELECTION ...................................................................................................................... 5
4.1.1 Cell selection monitoring set ............................................................................................................................. 5
4.1.2 Measurement for cell selection and reporting to higher layers ......................................................................... 5
4.2 MEASUREMENTS FOR CELL RESELECTION .................................................................................................................. 6
4.2.1 Content of the cell reselection monitoring set ................................................................................................... 6
4.2.2 Measurements for cell reselection and reporting to higher layers .................................................................... 6
4.3 MEASUREMENTS FOR LOCATION SERVICES ............................................................................................................... 6
5 MEASUREMENTS IN CONNECTED MODE .......................................................................................................... 7
5.1 MEASUREMENTS FOR THE HANDOVER PREPARATION ................................................................................................. 7
5.1.1 Cell sets for the handover preparation .............................................................................................................. 7
5.1.1.1 Overview of the different sets.........................................................................................................................................7
5.1.1.2 Content of the sets ..........................................................................................................................................................7
5.1.1.2.1 handover monitoring set .........................................................................................................................................7
5.1.1.2.1.1 TD-SCDMA cells ............................................................................................................................................8
5.1.1.2.1.2 GSM cells ........................................................................................................................................................8
5.1.1.2.2 active set .................................................................................................................................................................8
5.1.1.2.3 candidate monitoring set .........................................................................................................................................8
5.1.2 Measurement triggering criteria........................................................................................................................ 9
5.1.3 Measurements for the handover preparation at the UE .................................................................................... 9
5.1.3.1 In general........................................................................................................................................................................9
5.1.3.2 Measurements for the intra-system handover preparation at the UE ..............................................................................9
5.1.3.2.1 In general ................................................................................................................................................................9
5.1.3.2.2 Monitoring of TD-SCDMA cells ............................................................................................................................9
5.1.3.2.3 Parametrisation/introduction of idle periods ...........................................................................................................9
5.1.3.2.4 Reporting the Measurement Results to higher layer ...............................................................................................9
5.1.3.3 Measurements for the inter-system handover preparation at the UE ............................................................................10
5.1.3.3.1 Handover to FDD..................................................................................................................................................10
5.1.3.3.2 Handover to GSM .................................................................................................................................................10
5.1.3.3.2.1 Introduction ...................................................................................................................................................10
5.1.3.3.2.2 Monitoring GSM using idle times lots ..........................................................................................................10
5.1.3.3.3 Overall handover preparation at the UE ................................................................................................................10
5.1.4 Mesurements for the Handover preparation at the RAN side .......................................................................... 10
5.1.5 Measurement reporting to the higher layers ................................................................................................... 11
5.1.5.1 Reporting scheme .........................................................................................................................................................11
5.1.5.2 Measurement report content for TD-SCDMA cells......................................................................................................11
5.1.5.3 Measurement report content for GSM cells ..................................................................................................................11
5.1.5.4 Measurement report content for DCA ..........................................................................................................................11
5.2 MEASUREMENTS FOR THE CELL RESELECTION IN ACTIVE MODE............................................................................... 11
5.3 MEASUREMENTS FOR POWER CONTROL ................................................................................................................... 12
5.4 MEASUREMENT FOR SYNCHRONIZATION.................................................................................................................. 12
5.4.1 Spreading Code Synchronization .................................................................................................................... 12
5.4.1.1 Synchronization Establishment ....................................................................................................................................12
5.4.1.2 Synchronization Maintenance ......................................................................................................................................12
5.4.2 Frame Synchronization .................................................................................................................................... 13
5.4.2.1 Beacon Synchronization ...............................................................................................................................................13
5.5 MEASUREMENTS FOR DCA...................................................................................................................................... 13
5.5.1 Measurements for DCA when connecting to the TD-SCDMA system.............................................................. 13
5.5.2 Measurements for DCA when in connected mode ........................................................................................... 14
5.5.2.1 Measurements by the UE..............................................................................................................................................14
5.5.2.2 Measurements by the Node B .......................................................................................................................................14
Physical layer – Measurements (TD-SCDMA)
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5.6 MEASUREMENTS ADJACENT PROTECTION CHANNELS ...................................
5.6.1 Frequencies to measure ................................................................................................................................... 14
5.6.2 Measurement to perform .................................................................................................................................. 14
5.7 MEASUREMENTS FOR LOCATION SERVICES (LCS)................................................................................................... 15
5.7.1 Forward Link Location (Multiple BSs Locating) ............................................................................................. 15
5.7.1.1 Operation ......................................................................................................................................................................15
5.7.1.2 Measurements...............................................................................................................................................................15
5.7.1.2.1 UE (mobile station) Support for OTDOA measurement .......................................................................................15
5.7.1.2.2 UE Support for Round Trip Delay (RTD) Measurement ...................................................................................16
5.7.1.2.3 Node-B Support for Round Trip Delay (RTD) Measurement ............................................................................16
5.7.2 Reverse Link Location (Single BS Locating) ................................................................................................... 16
6 RADIO LINK MEASUREMENTS ...................................................................................................................................... 17
6.1 DEFINITION OF MEASUREMENT PARAMETERS........................................................................................................... 17
6.2 DOWNLINK/UPLINK INTERFERENCE MEASUREMENT ................................................................................................ 17
6.3 PATH DELAY (PD) MEASUREMENT........................................................................................................................... 18
7 HISTORY ..................................................................................................................................................................... 19
Physical layer – Measurements (TD-SCDMA)
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1 Foreword
This Technical Specification (TS) has been produced by CWTS working group 1 (CWTS WG1). The contents of the TS
are subject to continuing work within CWTS WG1 and may change following formal TSG approval.
2 Scope
This CWTS Specification specifies the physical layer measurements done at the UE and network of TD-SCMA systems.
Such measurements involved in idle mode and connected mode are described respectively.
In idle mode, this specification describes the following :

measurements for the cell selection

measurements for cell reselection
In connected mode, this specification provides the minimum requirements for the UE and networks, and mainly
describes the measurement for:
 the handover preparation
 the cell reselection in active mode
 the power control
 the system synchronization
 supporting DCA
 the adjacent protection channel
In corresponding clauses, some explanatory text which is more of a descriptive nature than normative should also be
contained in the TS.
For the handover preparation, this specification defines the measurement requirements of intra-cell handover and
inter-cell handover to the UE and TD-SCDMA RAN. The inter-cell handover may include the handover from
TD-SCDMA to GSM.
In addition, this specification also describes the measurements for supporing location services and monitoring radio link.
3 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
[1] 3GPP TS S25.221 Physical channels and mapping of Transport channels onto physical channels
[2] CWTS TS C101(V.2.0.0) Physical layer-general description
[3] CWTS TS C 102(V. 2.0.0) Physical channel and mapping of transport channels onto physical channels
[4] CWTS TS C 103 (V. 2.0.0) Multiplexing and channel coding
[5] CWTS TS C 104 (V. 2.0.0) Spreading and modulation
[6] CWTS TS C 105 (V. 2.0.0) Physical layer procedures
[7] CWTS TS C 001(V. 2.0.0) Radio Interface Protocol Architecture
Physical layer – Measurements (TD-SCDMA)
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[8] CWTS TS C 002(V. 2.0.0) Services provided by the
Physical layer
[9] CWTS TS C 003(V. 2.0.0) UE functions and inter-layer procedures in connected mode
[10] CWTS TS C 004(V. 2.0.0) UE procedures in idle mode
[11] 3GPP TS 25.302 V2.3.0 Services provided by the Physical Layer
[12] ETSI GSM 05.08 (ETS 300 911): “Digital cellular telecommunications system (Phase2+); Radio subsystem
link control”. Version 5.4.0
[13] TR 25.923 v1.4.0 Stage 2 Functional Specification of Location Services in UTRAN
[14] GSM 03.03 (ETS 300 927): “Digital cellular telecommunications system (Phase2+); Numbering, addressing
and idetification”. Version 5.0.2
4 Measurements in idle mode
<Editor’s note: Measurement to support Cell selection and cell reselection rely on synchronization acquisition
procedures currently described in the Initial cell search procedures (section 6.7 in [6]). After switching on, the UE
always attempts to find a suitable cell to camp on, the cell selection and re-selection procedures ensure the UE’s
camping on a cell. Therefor, the purposes of measurements in idle mode are for cell selection and cell reselection.>
4.1 Measurements for cell selection
Measurements for cell selection in physical layer are triggered by some events (e.g. power on). This section is divided
into the following sub-sections, i.e,“Cell selection monitoring set” and “Measurement from the cell selection
monitoring set and reporting to higher layers”
4.1.1 Cell selection monitoring set
Cell selection monitoring set is a list of neighbour cells of the selected network including information how to read the
BCH in the corresponding each cell. (This list may be derived by the UE from information gathered during previous
selections of the PLMN).
[Editor’s note: This section should define how the cell selection monitoring set is determined. This set should be
provided by higher layers through the primitive that triggers the measurement process. The provision, of course, of
such set should specified in other specification, e.g. MAC protocol specification. Two following two cases might be
considered and would lead to two different cell selection monitoring.

Normal cell selection: the UE has no information about BCH channel at switch on. It would perform measurements
on frequencies/cell that may be manually selected if applicable.This process can be completed by three steps as
described in section 6.7 of [6].

Cell selection from stored list. The UE stored some information about BCH channel at switch off. At switch on cell
selection is performed based on this stored information.
In both above cases, the UE autonomously carries out the measurements without reporting to the RAN and selects a
suitable cell to camp on according to some cell selection criteria.]
4.1.2 Measurement for cell selection and reporting to higher layers
The content of measurements from the cell selection monitoring set and reporting to higher layers may include:
 SIR
 Path loss
 Interference power
 Received power level on BCH, etc.
<Editor’s note : Such requirements may be refined based on consideration of higher protocol, the measurement
precision and conditions which could affect the precision is FFS.>
Physical layer – Measurements (TD-SCDMA)
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These measurements results described above are reported to
higher layer (MAC and/or RRC) using the primitives between physical layer and the higher layer with some parameters
which need to be defined in other documents of protocol specification. Such primitives may be CPHY-Measurement
(request/indication) and/or PHY-Measurement (request/indication).
4.2 Measurements for cell reselection
[Editor’s note:This section should define how the cell reselection monitoring set is passed to the physical layer of the
UE by higher layers and what information is passed in terms of cell mode, frequency, synchronisation information, etc.
This set should be provided by the MAC layer in the primitive that triggers the measurement process.]
From a very general descriptive view, When in idle mode, the UE may need to select a different cell, i.e. cell reselection
under the conditions following:
 too high path loss to the cell camping on;
 downlink signalling failure;
 current cell unavailable;
 existing a better cell in the same RAN;
 unsuccessful random access attempt after the max repetitions.
The measurements for the cell reselection are performed in basically the same way as the cell selection. The main
difference compared to the cell selection is that a UE has received a priority list from the RAN, called the cell
re-selection monitoring set, which provides information relative to the cells to monitor. Upon completion of cell
selection and when starting the cell reselection, the UE shall synchronize with the 3 or 4 strongest non-serving cells and
demodulate their BCH information as quickly as possible.
[Editor’s note: For dual-mode UE, the strongest non-serving cells may inclede the GSM cell.]
4.2.1 Content of the cell reselection monitoring set
The cell reselection monitoring set priority list provides the list of cells and the order to search, as well as information
about these cells in the same way as the Handover Monitoring Set.
<Editor’s note : it is to be confirmed that the list provides some indication of the order in which the cells have to be
searched for. >
4.2.2 Measurements for cell reselection and reporting to higher layers
As described in section 4.1.2, the content of measurements from the cell reselection monitoring set and reporting to
higher layers may include:
 SIR
 Path loss
 Interference power
 Received power level on BCH, etc.
<Editor’s note : Such requirements may be refined based on consideration of higher protocol, the measurement
precision and condition which could affect the precision is FFS,.>
These measurements results described above are reported to higher layer (MAC and/or RRC) using the primitives
between physical layer and the higher layer with some parameters which need to be defined in other documents of
protocol specification. Such primitives may be CPHY-Measurement (request/indication) and/or PHY-Measurement
(request/indication).
4.3 Measurements for Location Services
The general operation for measurements for the Location Service (LCS) is outlined in sub-section 5.7.1. In the idle
mode, the UE shall be able to measure the observed time difference of the (downlink) pilot signals. The measurement
process by the UE is triggered by an internal UE operation (e.g. power on or change of cell) while in the idle state. The
Physical layer – Measurements (TD-SCDMA)
7
carriers to be measured shall include those in the “cell
selection set” and those in the“cell reselection and monitoring set”. The measurements shall be as outline in sub-section
5.7.2.1.
5 Measurements in connected mode
5.1 Measurements for the handover preparation
5.1.1 Cell sets for the handover preparation
[ Editor’s note: A cell set corresponds a list of cells that the UE needs to monitors for a given period of time, with
associated requirements, as seen from the physical layer. Several sets are defined since different requirements might be
defined, e.g. some cells might need to be monitored more often than others…It is not clear at this stage how such sets
will be provided by higher layers. The primitives that allow the higher layers to control the measurement process in the
layer 1 will be specified in corresponding higher layer documents. Several cases might be considered :

the MAC has a very fine control of the measurement, upto the frame level, decides on the measurement of
particular cells at particular instant and the physical layer report measurement back to the MAC layer e.g. after a
compressed frame, some processing being possibly needed by the MAC

The MAC provides sets of cells to monitor and monitoring periods, it is up to the physical layer to organise the
monitoring
In the following we consider the second case, because it is more in line with the available documentation from .t The
first case of some intermediate case was to be considered in the future then some material of the section would need to
be move to the corresponding higher layer documents.>
5.1.1.1 Overview of the different sets
The physical layer of the UE should be provided by higher layers the following lists of cells :
 Handover Monitoring set: All cells (TD-SCDMA or from other systems like GSM) that the UE has been tasked by
the RAN to monitor when in active mode.
 Active Set: The TD-SCDMA cells currently assigning a downlink DPCH to the UE, which corresponds to the cell
between which the UE in a soft handover with. The active set may only correspond to TD-SCDMA cells.
 Handover candidate set: The cells that are not currently in the Active Set but have been received by the UE with
sufficient strength to indicate that the associated DPCHs could be successfully demodulated. These correspond to the
cells that are effectively reported by the UE to the RAN. These cells may be on the same or different frequencies
from the current frequency assignment. Cells in the handover candidate set may be TD-SCDMA or GSM cells.
<Editor’s note : Since the scope of this specification to the measurement only, there might not be a need to define the
same sets. Only set that would lead to different requirements or process for the measurement need to be defined. Here it
is anticipated that cells in the active set, which are the serving cell are measured for each frame, whereas cell which are
not part of the active set are not measured as often as every frame. Cells which have been identified by the higher layers
as candidate cell may need to be measured more often than other cell, since they are among the x strongest. >
5.1.1.2 Content of the sets
5.1.1.2.1 handover monitoring set
[Editor’s note: In order to ensure the successful handover, the handover moitoring cells set may include the cells of
other systems like GSM for the multi-mode UE.]
The handover monitoring set contains the cells to be monitored by the UE in connected mode. It is provided to the
physical layer by higher layers, as part of the primitives (see [6]). The handover monitoring set may contain cells on the
same frequency and/or cells on different frequencies.
Physical layer – Measurements (TD-SCDMA)
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5.1.1.2.1.1 TD-SCDMA cells
Each TD-SCDMA cell to monitor in the handover monitoring set contains:
 a frequency information;
 an information field CELL_PARAM for the cell parameters (toffset, midamble code, and scrambling code);
 the relative timing of the cell (if available).
Each UE has stored a ‘cell parameter list’ (see table below) which maps the CELL_PARAM value to one out of 128 sets
of cell parameters. The list is common to TD-SCDMA systems.
Each set has a unique basic midamble code and a unique scrambling code. Furthermore, each set has a toffset out of 32
different values.
CELL_PARAM
0
1
2
3
4
5
6
7
Basic midamble
mP0 (see mP in C102)
MP1
MP2
MP3
MP4
MP5
MP6
MP7
Scrambling code
Code 0
Code 1
Code 2
Code 3
Code 4
Code 5
Code 6
Code 7
toffset
t0
124
125
126
127
mP124
mP125
mP126
mP127
Code 124
Code 125
Code 126
Code 127
t31
t1
Note: According to CWTS TS C104, the number of scrambling code is only 22.
5.1.1.2.1.2 GSM cells
Each GSM cell to monitor in the handover monitoring set contains:
 frequency information;
 cell identification information (CGI, LAC,LAI, CI, etc. See also [14]);
 the timing relationship between TD-SCDMA and GSM cells (if available).
5.1.1.2.2 active set
The cells in active set refer to the serving cells under the baton handover. They are only the TD-SCDMA cells. See also
the sub-section 5.1.1.2.1.1.
5.1.1.2.3 candidate monitoring set
As a design goal, only the 6(?) cells are contained in the Handover Monitoring Set, but not all of measuring results from
these cells is available. Therefore, it is necessary to choose some cells as candidate cells composing the candidate set. It
may contain the TD-SCDMA and GSM cells.
Physical layer – Measurements (TD-SCDMA)
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5.1.2 Measurement triggering criteria
< Editor’s note: Depending on the primitive between the physical layer and the higher layer, the monitoring of
particular cell would start at the reception of the primitive, or might be conditioned to e.g. the quality of the serving
cells. This is to be determined>
5.1.3 Measurements for the handover preparation at the UE
5.1.3.1 In general
The following subsections describe the measurements to prepare an intra-system handover and inter-system handover
(from TD-SCDMA to GSM). For the handover preparation, the UE has to monitor other cells as well as its own cell.
Apart from the destination cell types (TD-SCDMA or GSM) the following measurements should be performed by the
UE for the serving TD-SCDMA cell:
 BER of the serving DL channel before channel decoding
 BER on DL transport channel after channel decoding
 reception level of DL channel
The following measurements should be performed by the Node B for the serving TD-SCDMA cell:
 BER of the serving UL channel before channel decoding
 BER on UL transport channel after channel decoding
 reception level of UL channel
5.1.3.2 Measurements for the intra-system handover preparation at the UE
5.1.3.2.1 In general
For the preparation of the intra-system handover, the UE performs measurements in its idle timeslots to the neighbour
TD-SCDMA cells given in the Handover Monitoring Set.
5.1.3.2.2 Monitoring of TD-SCDMA cells
During the measurement process, the UE shall find synchronization to the cells to measure using the synchronization
channel with synchronization code and the information contained in the cell parameter list. Alternatively, the midamble
of the CCPCH may be used for purpose of synchronization in case the relative timing to the new cell is provided by the
network.
The following information is obtained by the UE either from measuring the synchronization channel or the midamble of
the CCPCH:
-
signal strength of the measured cell
-
relative timing between the cells, measured from the timing of the downlink synchronous Gold code
5.1.3.2.3 Parametrisation/introduction of idle periods
Normally the UE is able to use the idle time slots between transmission and reception for monitoring neighbor cells.
However the DCA may also introduce idle time slots if necessary.
5.1.3.2.4 Reporting the Measurement Results to higher layer
These measurements results obtained by UE are reported to higher layer (MAC and/or RRC) using the primitives
between physical layer and the higher layer with some parameters which need to be defined in other documents of
protocol specification. Such primitives may be CPHY-Measurement (request/indication) and/or PHY-Measurement
(request/indication).
Physical layer – Measurements (TD-SCDMA)
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5.1.3.3 Measurements for the inter-system
handover preparation at the UE
5.1.3.3.1 Handover to FDD
If the UE supports the FDD mode, the mutil-mode UE performs measurements to the FDD cells given in the Handover
Monitoring Set for preparation of a handover from TD-SCDMA to FDD in its idle time slots. In these idle time slots the
UE has to synchronize to the monitored FDD cell using the FDD synchronization channel and to measure:

Ec/I0 of the primary CCPCH

Relative timing of the two systems (TDD and FDD)
5.1.3.3.2 Handover to GSM
5.1.3.3.2.1 Introduction
The handover to GSM system offering world-wide coverage already today has been one of the main design criteria taken
into account in the TDD frame timing definition. The GSM compatible multi-frame structure, with the super-frame
being multiple of 120 ms, allows similar timing for inter-system measurements as in the GSM system itself. The
compatibility in timing is important, that when operating in TDD mode, TD-SCDMA/GSM UE is able to catch the
desired information from the synchronisation bursts in the synchronisation frame on a GSM carrier with the aid of the
frequency correction burst. This way the relative timing between a GSM and TDD carriers is maintained similar to the
timing between two asynchronous GSM carriers.
TD-SCDMA/GSM dual mode terminals can be implemented without simultaneous use of two receiver chains. Although
the frame length is different from GSM frame length, the GSM traffic channel and TD-SCDMA channels rely on similar
120 ms multi-frame structure.
A UE can do the measurements either by efficiently using idle slots (Slot left idle between Tx and Rx and/or rRx and
TX as a result of the resource allocation) or by requesting free continuous periods in the downlink part obtained by
reducing the spreading factor and compressing in time TS occupation in a form similar to the FDD slotted mode. The
details of the latter are for further study. Other alternatives, e. g. dual receiver, are for further study. Basic requirements
to correctly perform a handover in GSM are described in GSM 05.08 “Radio subsystem link control”.
5.1.3.3.2.2 Monitoring GSM using idle times lots
Two kinds of UE should be distinguished:
 A single synthesiser UE has to switch in its idle periods from the TDD frequency to the considered GSM frequency,
monitor GSM and switch back to TDD afterwards, that means two times a synthesiser switching time has to be
considered.
 A dual synthesiser UE avoids this synthesiser switching time and the monitoring periods are equal to the idle
periods.
For preparation of a handover to GSM there are two possible procedures

To detect at first the FCCH burst and then the SCH burst (following one GSM frame later)

or searching parallel for FCCH and SCH bursts.
5.1.3.3.3 Overall handover preparation at the UE
This section should explain how the inter-system and intra-system handover preparation are co-ordinated in terms of
measurement and reporting at the UE. This section provides the overall requirement and measurement procedure witch
is FFS.
5.1.4 Mesurements for the Handover preparation at the RAN side
<Editor’s note : The handover triggering might not be due only to conditions on the downlink. Measurements
performed by the cells in the active set might be needed as in GSM. This section should be created for that purpose >
Physical layer – Measurements (TD-SCDMA)
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For the intra-handover preparation , the serving Node B shall
carry out the following measurements for the UE under consideration:
 Received signal strength
 SIR of serving link after despreading
 BER of the serving UL DPCH before channel decoding
 BER on UL transport channel after channel decoding
Furthermore, an information about the timing advance should be available at the Node B.
5.1.5 Measurement reporting to the higher layers
<Editor’s note : This section should be updated in order not to make any assumption on the reporting scheme between
the UE and the RAN but deal with only reporting to higher layers>
5.1.5.1 Reporting scheme
The UE sends regular (or event driven) measurement reports to the RAN. The level of filtering done by the physical
layer vs. the filtering done by higher layers needs to be further discussed.
5.1.5.2 Measurement report content for TD-SCDMA cells
These measurement reports include:
 The cell identification
 The relative signal strength
 The relative timing information (if needed)
5.1.5.3 Measurement report content for GSM cells
In order to ensure the efficient handovers, the rate of both refrenshing the measurements and reporting the results should
be as high as possible. For GSM cells, the measurement report content may include:




The GSM cell identification
The received FCCH signal strength
The relative timing information (if needed)
The UE’s transmission power
5.1.5.4 Measurement report content for DCA
Depending on whether the respective points apply, the following data are reported for DCA:








Pathloss of a sub-set of cells (7 bit quantisation; max. number of cells is30)
Interference of all DL time slots requested by the RAN (5 bit quantisation)
SIR of serving link after despreading
BER of serving link before channel decoding (4 bit quantisation)
BER on transport channel before channel decoding ([4] bit quantisation)
FER on transport channel
Transmission power of the UE on serving link (6 bits quantisation)
DTX flag indicating, whether measurements have been performed during DTX periods
5.2 Measurements for the cell reselection in active mode
<Editor’s note : Depending on state the UE is in while in connected mode, the cell change operation can be performed
using various procedures, such handover or cell reselection. Cell reselection might be appropriate for packet
transmission. As an example this is what is done in GSM GPRS. Such measurement requirements should be defined as
soon as possible after that the corresponding procedures are clarified.>
When in active mode, the UE continuously searches for new base stations on the current carrier frequency. This cell
search is carried out in basically the same way as the idle mode cell search.
Physical layer – Measurements (TD-SCDMA)
12
5.3 Measurements for power control
<Editor’s note : there is presently no measurement defined for the support of power control that is reported over the
radio. There might be however layer some measurements exchanged between the different RAN entities and that will
need to be standardised in relation with power control. >
The following measurements are performed by the UE and reported to the RAN:
 Received signal strength of serving DL DPCH
 BER of serving DL DPCH before channel decoding
 BER on transport channel after channel decoding
 SIR of serving DL DPCH after despreading
 Interference on DL DPCH
Furthermore, in the UE the following information shall be monitored:
 Received signal strength of serving CCPCH midamble
 UE transmit power
The following measurements are performed by the RAN:
 Received signal strength of UL DPCH
 BER of serving UL DPCH before channel decoding
 BER on transport channel after channel decoding
 SIR of serving UL DPCH after despreading
Furthermore, in the Node B the following information shall be monitored:
 Transmit power per DL DPCH code
 Dynamic of UL received signal strength for Joint Detection (if used in the Node B)
 Dynamic of DL transmit signal strength for Joint Detection (if used in UE)
 Interference in each UL timeslot
5.4 Measurement for synchronization
[Editor’s note: In TD-SCDMA system, the synchronization refers to the spreading code synchronization and frame
synchronization. In connected mode, the RAN tempts to maintenance the UL/DL synchronization among UEs for the
purpose of reducing MAI, and achieve the system synchronization among Node Bs in order to decreasing the cross
interface level of system. The DL synchronization can be easily realized and can minimize the measurement. But the UL
synchronization under connected mode implemented through midamble sequence should require corresponding
measurements for derivation of SC information, e.g. TA. For the frame synchronization of TD-SCDMA system, there
are two types of scheme, i.e. Beacon (hierarchical) synchronization and Non hierarchical synchronization. In the first
one, the timing difference between the special Node B and the beacon BS should be measured and reported through the
air interface. In the second one, though there does not exist the synchronisation timing, but it may be necessary to
measure the phase difference between two Node Bs.
5.4.1 Spreading Code Synchronization
5.4.1.1 Synchronization Establishment
When powered on, UE will search the strongest SYNC sequence from the nearby Node Bs (such downlink
synchronization can easily acquire). After this, the UE estimates the Tx time and sends the SYNC1(orthogonal
Gold code sequence) on UpPTS. According to the received SYNC1 from UE, the serving Node B can constructs
the control signaling field SS. Having received SS from FACH, UE adjusts its estimated Tx time to establish the
closed uplink sychronization. Therefore only measurements for synchronisation establishment at UE is necessary.
The measurements performed by UE include:
■
received time and power level of the received training sequence SYNC
5.4.1.2 Synchronization Maintenance
In each dedicated traffic channel of UL, midambles of different users active in the same slot are time shifted
versions of one single periodic basic code, so they can be sequentially detected in Node B. According to the
expected arrival time, Node B calculates the uplink synchronization tolerance of the UE and hence feed back the
SS information .So the UE can adjust its Tx time correctly .
The following measurements are performed by Node B:
■
arrival time of the midamble sequence within each UL DPCH
Physical layer – Measurements (TD-SCDMA)
13
[Editor’s note: The arrival time is compared with the
expected time, then the SS can be calculated in the resolution of 1/2 chips or even higher resolution.]
5.4.2 Frame Synchronization
[Editor’s note: Considering the features of TDD-system, frame synchronization via air-interface is adopted because it
may make real-time DCA comparatively easy.]
5.4.2.1 Beacon Synchronization
In this scheme of synchronization, there is a master synchronisation unit (the main area beacon) to provide the
synchronisation timing for a whole area, e.g. a city. Some Node Bs have direct synchronization link with the main area
beacon. Thus synchronization within a local sub area can be done either by a main area beacon or by such beacon Node
Bs.
The following measurements are performed by beacon Node B:
■
received signal strength of synchronization burst in reserved frame synchronization timeslot
■
propagation delay between the main area beacon and the beacon Node B
■
frame timing offset
[Editor’s note: During the measurements of synchronisation burst, the RF transmission amplifiers of the own Node B
must be switched off to avoid blocking effects. The structure of synchronisation burst is ffs.]
5.4.2. 2 Non- hierarchical Synchronization
This approach doesn’t need any hierarchy relation for the synchronization path. The main synchronisation requirement is
that the phase difference between two Node Bs has to be within a limit. Each Node B synchronises to all adjacent Node
Bs.
The following measurements are performed by each Node B:
■
the phase difference to adjacent Node Bs
■
the propagation delay to adjacent Node Bs
■
phase drift △Φ
5.5 Measurements for DCA
DCA is used to optimise the resource allocation by means of channel quality criteria or traffic parameters. The DCA
measurements are configured by the UTRAN and the UE reports the measurements to the UTRAN.
Since measurements for DCA in idle mode should be minimised, two cases have to be distinguished: The initial case
performing DCA measurements when connecting to the TDD system and the case of performing DCA measurements in
connected mode.
5.5.1 Measurements for DCA when connecting to the TD-SCDMA system
With the initial access the UE immediately starts measuring the relevant time slots which are communicated on the BCH.
These measurements (including averaging over a certain period) are done while the RAN assigns an UL channel for the
UE for measurement reporting. The following measurements have to be performed at the UE:

Received signal strength of CCPCH midamble of serving cell (to calculate pathloss)

Total received power on DL time slots according to a list provided by the RAN

Received signal strength of CCPCH midamble of other cells (using the corresponding transmit power, known to the
network, the pathloss can be calculated) provided by the RAN
The content of the measurement report is given in section 5.1.5.4.
Using the reported measurements, the RAN selects the appropriate resource units for the requested service.
Physical layer – Measurements (TD-SCDMA)
14
5.5.2 Measurements for DCA when in
connected mode
5.5.2.1 Measurements by the UE
While in active mode the DCA needs measurements for the reshuffling procedure (intra-cell handover). The following
measurements have to be performed by the UE periodically:
 Received signal strength of CCPCH midamble of serving cell (to calculate pathloss)
 Total received power on DL time slots according to a list provided by the RAN
 Received signal strength of CCPCH midamble of other cells (using the corresponding transmit power, known to the
network, the pathloss can be calculated) provided by the RAN
 SIR of serving DL DPCH after despreading



Estimation of BER of serving DL DPCH before channel decoding
Estimation of BER on DL transport channels after channel decoding
Estimation of FER on DL transport channels
5.5.2.2 Measurements by the Node B
The following measurements have to be performed by the Node B in order to support DCA:
 Interference measurements of uplink time slotsaccording to a list provided by the RAN (5 bit quantisation)
 SIR of serving UL DPCH after despreading
 Estimation of BER of serving UL DPCH before channel decoding
 Estimation of BER on UL transport channels after channel decoding
 Estimation of FER on UL transport channels
<editor’s note: In addition, the RLC informs the DCA about transmission errors. The interaction between DCA and
RLC depends on the RLC operation mode. Details are FFS.>
5.6 Measurements adjacent protection channels
<Editor’s note : some additional measurement might be needed in order to provide the network with information on
adjacent channel interference. >
5.6.1 Frequencies to measure
On the BCCH, RAN transmits frequency information of candidate frequencies and neighbouring frequencies. A
candidate frequency is defined as a frequency that can be used by the own network, and a neighbouring frequency is
defined as a frequency that is adjacent to a candidate frequency. Candidate frequencies are classified into adjacent
frequencies and non-adjacent frequencies. An adjacent frequency is defined as a candidate frequency that is adjacent to
a neighbouring frequency, and a non-adjacent frequency is defined as a candidate frequency that is not adjacent to a
neighbouring frequency.
5.6.2 Measurement to perform
To support adjacent channel protection rule, an MS measures Q 1 and Q2 , where Q1 is the received power in dBm of the
downlink adjacent frequency, and Q2 is the received power in dBm of the downlink neighbouring frequency that is
adjacent to the downlink adjacent frequency.
Physical layer – Measurements (TD-SCDMA)
15
5.7 Measurements for Location Services
(LCS)
5.7.1 Forward Link Location (Multiple BSs Locating)
5.7.1.1 Operation
The standard OTDOA-RTD location method involves measurements of the RAN radio transmissions made by the UE
and the Node-B (or LMU). These measures are then sent to a Position Calculation Function (PCF) in the Serving RNC
where the location of the UE is calculated (see reference [13] ). As the location estimate is derived from timing measures,
these must be made to sufficient resolution to achieve the desired accuracy. A 50 meters uncertainty in distance requires
a total timing uncertainty of less than 150 nanoseconds1. This is about 5 chip time. The measures for LCS are similar to
those performed by the UE for handover with, perhaps, a finer resolution of timing measurement.
The primary standard measurements are of the observed time difference of arrival (OTDOA) of downlink signals
received at the UE. These measurements, together with other information concerning the surveyed geographic location
of the transmitters and the relative time difference (RTD) of the actual transmissions of the downlink signals may be
used by the PCF to calculate an estimate of the position of the UE. Each OTDOA measurement for a pair of downlink
transmissions describes a line of constant difference (hyperbola) along which the UE may be located. The UE’s
position is determined by the intersection of these lines for at least two pairs of transmitters. In most cases these
measurements will be sufficient.
Under some circumstances, a sufficient number of downlink signals may not always be available. In these cases, a
secondary measure is provided. The secondary measure is of the Round-Trip-Delay (RTD) for transmissions between
the serving transmitter and the UE. This measurement defines a line (arc) of constant distance (radius) from the
transmission site in the sector served. This measure may be used to supplement the TDOA measurements with the
location of the UE being the intersection of the arc from the serving transmitter and the line of constant difference
(hyperbola) between the serving and second transmitter sites.
In the event that sufficient primary measures are available, the secondary measure is not needed. However, with the
use of the secondary measure, the location may be estimated even if the UE can only receive transmissions from two
transmitters. Studies of the pilot-to-carrier interference ratio for a number of environments have shown a 94%
coverage availability for at least one other pilot. The use of the OTDOA-RTD technique thus permits availability of
the LCS in the majority of the coverage area. In the remainder of the cases, the UE is typically very close to the
serving Node-B transmitter and its receiver is blocked by the strong local signals. In these cases the UE may be so close
to the transmitter that no other location information is needed beyond the RTD distance and sector estimate. If this is not
sufficient, then measurements may be made on other carriers or by other techniques such as the IS-DL described
elsewhere in reference [13].
As the LCS involves measurements, there is always uncertainty in the results. Physical conditions, errors and
resolution limits in the apparatus all contribute to uncertainty. To minimize the uncertainty in the LCS result, it is
important that as many measurements of OTDOA and RTD as are possible for a UE are provided to the PCF. Thus it is
important that the standard method for LCS not be restricted to rely on a single measure.
5.7.1.2 Measurements
This sub-section sumarises the requirements for the measurements to be made by the UE and the base station (Node-B)
for the basic LCS operation described in sub-section 5.7.1.
5.7.1.2.1 UE (mobile station) Support for OTDOA measurement
The UE shall be able to measure the observed time difference of the (downlink) pilot signals for carriers it can receive.
These measurements shall be reported to the highest resolution possible. A resolution of 1/2 chip duration is suggested
as a design goal. The minimum measured resolution shall be 1 chip duration. The resolution of the measurements shall
be indicated to the LCS process by appropriate signalling2 together with the measurements. The UE shall make these
measurements when requested by the network, or autonomously prior to making a request for location information.
These measurements may be made in the connected or the idle state.
1 As the total uncertainty has contributions from a number of measures, the resolution of individual measurements must be much better than this to
achieve the desired accuracy of result.
2 The signalling between the UE and the UTRAN LCS entities is beyond the scope of this document.
Physical layer – Measurements (TD-SCDMA)
16
The carriers to be measured shall include those in the “cell
reselection and monitoring set” and those in the “cell selection set”. Should these lists be empty, the measurements shall
be made for all signals received above the sensitivity limit of the receiver 3. As the signals from various base stations will
be received at (markedly) different signal levels, the UE shall also measure the signal strength of each measurement to
assist the calculation function (e.g. to apply more weight to the measurements of the stronger signals).
The UE shall also report the time-of-day the OTDOA measurements were made. [The system frame number of the
serving Node-B may be a convenient means of denoting time for these measurements. The UE may otherwise report
time-of-day in anther format agreed with the LCS process. ]
For each measured signal the UE shall report :

Timing difference with relation to the pilot signal of the serving transmitter (1/8 chip resolution);

Signal Strength of measured pilot (dBm)

The Time-of-day of the measurements (system frame number of serving transmitter);

Frequency offset of pilot carrier (0.01 Hz);
Resolution of the timing measurement (1/ fraction of chip duration )
5.7.1.2.2 UE Support for Round Trip Delay (RTD) Measurement
In order to support the use of the RTD measurement to assist the location service, the UE shall provide a resolution of
[1/4 chip] time, or less, in the measurement and timing of its uplink transmissions. The frame timing of the uplink
transmissions shall be maintained within this resolution with reference to an offset from the received downlink frame
timing. The jitter in the upstream transmission timing for shall also be less than this value. If the UE is capable of
better resolution (e.g. 1/4, 1/8 1/10 chip duration) this capability shall be indicated to the LCS process by means of
appropriate signalling.
5.7.1.2.3 Node-B Support for Round Trip Delay (RTD) Measurement
The Node-B shall be capable of measuring the Round Trip Delay (RTD) (or 1/2 that for one way delay (OWD)) for its
active UE. This measure is based on the delay between reference frame timing of the transmitted downlink transmissions
and the frame arrival time of the UE’s transmissions. This measure shall be made to resolution of 1/4 chip duration or
better. The resolution of the measurement (e.g. 1/4, 1/8 1/10 chips duration) shall be indicated to the LCS process by the
Node-B through appropriate signalling when the measurements are reported.
For each measured signal the Node-B shall report :

Round-Trip-Delay with relation to its transmission for selected UE (1/8 chip resolution);

Signal Strength of measured signals (average dBm)

The Time-of-day of the measurements (system frame number of serving transmitter);

Frequency offset of UE carrier (0.01 Hz) from carrier reference of Node-B;

Resolution of the timing measurement ( 1 / fraction of chip duration )
5.7.2 Reverse Link Location (Single BS Locating)
Thanks to the smart antenna technique in TD-SCDMA system, the reverse link location method (single BS) can be
adopted. There are two key parameters used for UE’s location estimation. They are:
 Direction of Arrival (DOA) of the uplink signal
 Path Delay (PD)
The DOA is for estimating the UE’s direction related the single serving BS; the PD can be used to estimate the distance
between the serving BS and locating UE.
3 It may not be necessary to measure quite all the received signals. At least the three strongest should be measured, together with as many others as
may provide reliable measurements.
Physical layer – Measurements (TD-SCDMA)
17
6 Radio link measurements
<Editor’s note : this section should described the measurements that are performed either at the UE or RAN side and
that are
 either reported and can be checked on the interfaces

or lead to some procedures in the mobile, leading to an expected behaviour of the said UE.
This section can provide some requirements on the measurement in terms of precision for various conditions. The
mapping of the raw values onto reported values with a limited range, where such reported values transit between layers
or across the interface should be also given. Only the acronyms are provide here>
6.1 Definition of measurement parameters
The following radio link measurement parameters can be used for: UL/DL open power control, handover evaluation,
initial power setting, calculation of pathloss, and path delay, etc.
RSCP: received Signal Code Power after de-spreading.
ISCP: interference on the signal code after de-spreading.
SIR : Signal to interference ratio, is defined as the RSCP divided by the ISCP.
RSSI : Received signal strength for useful part
ISSI : Interference signal strength
Tm: Relative timing difference between cells
<Editor’s note: Because the inter-BS synchronisation is needed in TDD mode, the value of Tm is equal to zero if the
propagating delay can be ignored.>
ΔTo: time difference between the first arrival time of DPCH frame in UE and the expected time for receiving DL
DPCH which can be expressed in (TTx ,UL  T0 ) , where, the TTx ,UL is UL Transmiting time in UE; and the T0 is the
time difference between the Ul Transmiting time and Dl Receiving time, it should be constant in TDD mode.
RTD(Round Trip Delay): is defined as the difference between the time of the uplink reception of the beginning of a
DPCH frame (first significant path of the path delay profile averaged over approx. [1 frame]) from the UE and the time
of transmission of the beginning of the corresponding downlink DPCH frame to a UE. It is given in chip units and its
range is TBD.
6.2 Downlink/Uplink interference measurement
[Editor’s note: The downlink/uplink interference measurement method is very important for capacity management of
Node B,so the measurement requirements should be minimum. Depending on the results, both the expected signal
power (signal strength) and the SIR can then be derive form de-spreaded signal level and the measured interference
level.]
The “unused reserved channelisation code method” to measure the downlink interference due to imperfect sampling
times should be possible. Network shall provide information about an unused channelisation code, i.e. the UEs will get
information that a code is unused. Similarly to the BCH, the actual channelisation code to use is hard-wired, so no
signalling is needed to say what code to use for this measurement.
Aided by the unused reserved channelisation code, the downlink interference in a certain cell and carrier frequency can
be measured by de-spreading the received signal with the channelisation code known to be unused.
Due to the orthogonal uplink channels in TD-SCDMA system, the “unused reserved channelisation code method” may
be a most suitable method for measuring the uplink interference. It is similar to the one used in downlink interference
measurement.
Physical layer – Measurements (TD-SCDMA)
18
6.3 Path delay (PD) measurement
In order to estimate the path delay which is usually used to calculate some parameters, e.g. the distance between Node B
and UE, the measurement of RTD is necessary. By doing that, the path delay can be expressed as following:
PD  ( RTD  T0 ) / 2
Physical layer – Measurements (TD-SCDMA)
19
7 History
V0.0.1
07.08.99
Draft module
V1.0.0
1999-08-30
Updated based on the WG1#5, August 30th,1999,Beijng.
V2.0.0
1999-10-14
Document accepted by CWTS WG1#5 in Beijing
The editor for CWTS C106 (Physical layer measurements) is
Lin Jinzhao
CUPT
Tel : +86 23 62460347, Fax : +86 23 62461412, e-mail: linjz@cqupt.edu.cn
This document is written in Microsoft Word 97.