IEEE C802.16m-09/3018
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Proposed Text on Enhanced LBS Support in Downlink (16.8.3)
Date
Submitted
2009-12-31
Source(s)
Alexey Khoryaev, Kamran Etemad, Alexander
Maltsev, Mikhail Shilov, Yang-seok Choi
Intel Corporation
E-mails:
alexey.khoryaev@intel.com
kamran.etemad@intel.com
alexander.maltsev@intel.com
Lei Zhou,Sangheon Kim, Xufeng Zheng,
Heewon Kang, Hokyu Choi
l.zhou@samsung.com
Samsung Electronics
sangheon.kim@samsung.com
Jinsoo Choi, HanGyu Cho, Jin Sam Kwak
js.choi@lge.com
LG Electronics
Roman Maslennikov
University of Nizhny Novgorod
Re:
Comments on IEEE P802.16m/D3 for IEEE 802.16 Working Group Letter Ballot
Recirc # 30b / Topic: LBS (Section 16.8.3)
Abstract
This contribution proposes amendment text describing design of downlink LBS zone
for enhanced LBS support
Purpose
To be discussed and adopted by TGm for theP802.16m/D4.
Notice
Release
Patent
Policy
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1
IEEE C802.16m-09/3018
Proposed Text on Enhanced LBS Support in Downlink
for the IEEE 802.16m AWD
Alexey Khoryaev, Kamran Etemad, Alexander Maltsev,
Mikhail Shilov, Yang-seok Choi
Intel Corporation
Lei Zhou, Sangheon Kim, Xufeng Zheng, Heewon Kang, Hokyu Choi
Samsung Electronics
Jinsoo Choi, HanGyu Cho, Jin Sam Kwak
LG Electronics
1. Introduction
This contribution proposes amendment text describing the design of Downlink-LBS (D-LBS) zone for
Enhanced LBS support in IEEE 802.16m systems and to be included in the IEEE 802.16m amendment
draft [5]. The proposed text is developed so, that it is compliant to the IEEE 802.16m SRD [2] and the
IEEE 802.16m SDD [3], and it follows the style and format guidelines in [4]. Current IEEE 802.16m
SDD [3] is used as a basis for the text development.
The D-LBS zone is introduced to improve the performance characteristics of non-GPS-based location
methods which rely on signal location parameters measured using reference signals transmitted by
serving and neighboring ABSs/ARSs of the network [3]. The proposed D-LBS zone facilitates more
accurate measurements of signal location parameters that are used for user positioning. The efficiency
of proposed method was verified in severe multipath channel and strong interference environment
using LBS evaluation assumptions defined in [6]. It was shown by link and system level simulations
[7], that implementation of D-LBS zone substantially improves accuracy of user positioning and meet
LBS requirements [2].
2. References
[1] IEEE P802.16Rev2/D9a, “Draft IEEE Standard for Local and Metropolitan Area Networks:
Air Interface for Broadband Wireless Access,” March 2009.
[2] IEEE 802.16m-07/002r8, “802.16m System Requirements”
[3] IEEE 802.16m-08/0034r2, “The Draft IEEE 802.16m System Description Document”
[4] IEEE 802.16m-08/043, “Style guide for writing the IEEE 802.16m amendment”
[5] IEEE P802.16m/D3, “Part 16: Air Interface for Fixed and Mobile Broadband Wireless
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IEEE C802.16m-09/3018
Access Systems – DRAFT Amendment to IEEE Standard for Local and metropolitan area
networks”
[6] IEEE C802.16m-09/2202 “System Level Evaluation Assumptions for LBS Performance
Analysis” (Alexey Khoryaev, Alexander Maltsev, Lei Zhou, Sangheon Kim, Fangmin Xu,
Jinsoo Choi, Kanghee Kim, Kunmin Yeo; 2009-09-22)
[7] IEEE C802.16m-09/2201r1 “Evaluation of D-TDOA Positioning” (Alexey Khoryaev,
Alexander Maltsev, Kamran Etemad et al; 2009-09-22)
[8] IEEE C802.16m-09/2314r2 “Proposed Text for Enhanced LBS Support (15.8.3)” (Lei Zhou,
Fangmin Xu, Xufeng Zheng, Zheng Zhao; 2009-11-17)
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IEEE C802.16m-09/3018
=========================Start of Proposed Text ==============================
[Note to Editor: Add the following underlined blue text into 16.8.3 Enhanced LBS Support section on
page 639]
16.8.3.1 Enhanced LBS support in downlink
The enhanced LBS support in downlink involves coordinated transmission of special location beacons
across multiple ABS’s in a designated Downlink LBS zone to facilitate AMS’s measurements of
parameters related to location determination.
16.8.3.1.1 Basic Description of Downlink LBS zone
To enable enhanced location determination, a dedicated Downlink LBS zone (D-LBS zone) may be
defined to transmit location beacons to be received by AMS’s and facilitate their measurement of
location related parameters (RD, RTD, RSSI, etc.) with the higher accuracy.
<<<< Start of the text for subframe based D-LBS zone option:
Such dedicated D-LBS zone, when supported, shall consume the entire downlink subframe and no
traffic shall be allocated by ABS/ARS’s inside such zone.
End of the text for subframe based D-LBS zone option >>>>
<<<<< Start of the text for distributed D-LBS zone option:
Such dedicated D-LBS zone, when supported, shall be spread over superframe and consume one
OFDM symbol in each frame and no traffic shall be allocated by ABS/ARS’s inside such zone.
End of the text for distributed D-LBS zone option >>>>>
The ABSs/ARSs configured to support D-LBS zone shall coordinate and transmit location beacons in
accordance with the predefined D-LBS transmission plan. The D-LBS zone can be configured for
either periodic or event triggered transmission modes.
In periodic mode, the D-LBS zone and associated location beacons are transmitted periodically
according to a period defined and broadcasted by the ABS.
In event-triggered mode the D-LBS zone and associated location beacons are transmitted only for a
window of time the start and duration of which are defined by the ABS. Within this window the DLBS zone may also be transmitted periodically, with a period also defined by the ABS. This mode may
be triggered by some events such as AMS/ABS’s request for high accuracy location for emergency or
other applications.
16.8.3.1.2 Allocation of D-LBS zone in frame structure
Depending on the used D-LBS zone transmission mode, a superframe may or may not contain D-LBS
zone. A superframe shall not contain more than one D-LBS zone.
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IEEE C802.16m-09/3018
<<<< Start of the text for subframe based D-LBS zone option:
When the D-LBS zone is allocated inside a superframe, its location shall be predefined and it shall be
placed in the first subframe of the last frame of the superframe. The D-LBS zone shall follow after the
normal SA-Preamble transmission and shall occupy remaining symbols of the first subframe. Figure 1
shows an example of D-LBS zone allocation for the D-LBS zone periodic transmission mode. The
parameter DLZP in Figure 1 is the D-LBS zone transmission period (DLZP) measured in superframes
units.
Period of D-LBS zone
SF 0
SF 1
SF 2
SF
DLZP
SF 3
SF
DLZP +1
SF
DLZP +2
SF
DLZP +3
Superframe 20 ms
SF 0
SF 1
SF 2
SF 3
Frame 5 ms
F0
F1
F2
F3
Subframe
SF0 SF1 SF2 SF3 SF4
SF5 SF6 SF7
Downlink
Uplink
Superframe header
PA-Preamble
SA-Preamble
Superframe with allocated
D-LBS zone
D-LBS Zone
Figure 1. D-LBS zone allocation
End of the text for subframe based D-LBS zone option>>>>
<<<<< Start of the text for distributed D-LBS zone option:
When the D-LBS zone is allocated inside a superframe, it shall consume 4 OFDM symbol per
superframe. These 4 symbols of D-LBS zone are evenly distributed over 4 frames of superframe. The
each special D-LBS zone symbol shall be placed at the first symbol of the first non type-3 subframe of
the DL frame and shall not be transmitted in the subframes where SA-Preamble or MIMO midamble
are transmitted. When the special D-LBS zone symbol is allocated in the type-1 AAI subframe case,
the remaining 5 consecutive symbols form a type-3 AAI subframe. For the type-2 AAI subframe case,
the remaining 6 consecutive symbols form a type-1 AAI subframe.
The D-LBS zone transmission period ( DLZ P ) is measured in superframes units.
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IEEE C802.16m-09/3018
Duration of D-LBS zone
Super
Frame 0
Super
Frame 1
Super
Frame 2
Super
Frame 2
Super
Super
Frame L-2 Frame L-1
D-LBS zone period (DLZP)
Frame 0
Frame 1
Frame 2
Frame 3
Frame
DL
SF0
DL
SF1
DL
SF2
DL
SF3
DL
SF4
UL
SF0
UL
SF1
UL
SF2
TTG
Subframe
SA-Preamble
PA-Preamble
Superframe header
D-LBS
symbol
D-LBS symbol
Type-3 subframe
Figure 2: Advanced air interface basic frame structure with D-LBS-zone
End of the text for distributed D-LBS zone option >>>>>
16.8.3.1.3 D-LBS zone transmission modes
There are two types of D-LBS zone transmission modes defined: the periodic mode and the event
triggered mode. Only one of these modes shall be supported by the ABS/ARS at the same time.
In the periodic mode, the D-LBS zone shall be allocated periodically all the time on a regular basis. Its
relative position during DL transmission is defined by the D-LBS zone period DLZ P . The D-LBS
zone shall start from the superframe number 0 and then repeat with the period DLZ P that specifies the
number of superframes between subsequently allocated D-LBS zones.
Period of D-LBS zone DLZP
SF 0
SF 1
SF 2
SF 3
Period of D-LBS zone DLZP
SF
DLZP
SF
DLZP+1
SF
DLZP +2
SF
DLZP +3
Period of D-LBS zone DLZP
SF
2DLZP
SF
SF
SF
2DLZP+1 2DLZP +2 2DLZP +3
Figure 3. D-LBS zone in periodic transmission mode
The period of D-LBS zone DLZ P may be set to one of the following values in superframe units: 4, 8,
16, 32.
In the event triggered mode, the D-LBS zone is transmitted on finite time interval and its position
inside of this time interval is configured by the three parameters DLZ P , DLZ O , DLZ N :
DLZ P is a period of D-LBS zone. It specifies the number of superframes between subsequently
allocated D-LBS zones.
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IEEE C802.16m-09/3018
DLZ O is an offset of the first D-LBS zone in superframe units relatively to the current superframe
count. It specifies the number of superframes to skip from the current superframe number, where new
D-LBS zone configuration was broadcasted. The D-LBS zone offset DLZO is set to one superframe by
default.
DLZ N - is a number of D-LBS zones to be subsequently allocated.
Figure 4 illustrates an example of D-LBS zone allocation in the event-triggered mode.
D-LBS zone
offset DLZO
SF
K-1
Number of subsequent D-LBS zones DLZN
Period of D-LBS zone DLZP
SF
K
SF
K+1
SF
K+DLZP
SF
K+DLZP+1
SF
(DLZN-1)DLZP
SF
(DLZN-1)DLZP +1
Superframe number (K-1) where information about D-LBS
configuration parameters is broadcasted, DLZO = 1 by default
Figure 4. D-LBS zone in the event-triggered transmission mode
16.8.3.4 D-LBS zone location beacon signals
The SA-Preamble shall be used as a reference location beacon signal for transmission inside D-LBS
zone. The physical structure of the SA-Preamble signal transmitted by each ABS/ARS in the D-LBS
zone shall be the same as defined in section 16.3.6.1.2.
Each ABS/ARS shall transmit the corresponding SA-Preamble signal in accordance with the
predetermined transmission plan that depends on the IDcell/segment parameter assigned to
ABSs/ARSs. The location beacon transmission plan provides time multiplexed transmission of these
reference signals across neighboring ABS/ARS’s to simplify AMS’s detection and measurements of
relevant signal location parameters from several ABSs/ARSs.
The D-LBS zone transmission plan spreads location beacon transmissions from different ABS/ARSs
over D-LBS zone OFDMA symbols. To facilitate wideband channel measurement the SA-Preamble
reference signals allocated in the D-LBS zone shall be transmitted from one transmit antenna.
16.8.3.4 Transmission plan of D-LBS zone
The D-LBS zone transmission plan specifies on which OFDMA symbol of D-LBS zone the location
beacons represented by SA-Preambles signal shall be transmitted. To define transmission plan the
existing set of SA-Preambles shall be partitioned into Q preamble location/LBS groups (PLGs). The
IDcells that belong to the i-th PLG (IDcellPLGi) shall be defined by equation (1) below:
IDcell PLGi  256  n  Idx PLGi ;
(1)
where i indicates the i-th preamble location/LBS group (PLGi), i  0, 1, ..., Q  1 ; Q shall be set to the
number of OFDMA symbols in the D-LBS zone ( DLZ NS ); n is the segment index defined in section
16.3.6.1.2, and Idx PLGi is the index belonging to the i-th PLGi that spans the following set of values [i :
Q : 255]. To determine the IDcells that belong to i-th PLG, the Idx PLGi index shall start from i and
increments by Q to 255 for each of the segment index n  0, 1, 2 .
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IEEE C802.16m-09/3018
<<<<< Start of the text for subframe based D-LBS zone option
The first symbol of the subframe that carrier the D-LBS zone shall be used for regular SA-Preamble
transmission. The remaining Q symbols representing D-LBS zone shall be occupied for transmission
by Q different PLGs. For the case of Q = 5, the D-LBS zone predefined transmission plan is specified
by Table 1.
Table 1. Predefined D-LBS zone transmission plan.
Segment
index
n
(Allocated carrier sets)
D-LBS zone symbol number
0
1
2
3
4
Carrier Set n = 0
PLG 0
PLG 1
PLG 2
PLG 3
PLG 4
Carrier Set n = 1
PLG 1
PLG 2
PLG 3
PLG 4
PLG 0
Carrier Set n = 2
PLG 2
PLG 3
PLG 4
PLG 0
PLG 1
End of the text for subframe based D-LBS zone option >>>>>
<<<<< Start of the text for distributed D-LBS zone option
The Predefined D-LBS zone transmission plan is specified by
Table 2 and is shown in Figure 5. 6 reference signals are allocated for 6 neighbors BS. And three
sectors of every neighbor BS use the same allocated reference signal.
RS5
RS3
RS4
RS2
RS4
RS5
4th symbol
RS0
RS1
RS1
3rd symbol
RS3
2nd symbol
RS2
RS0
1st symbol
E-LBS-Zone
Figure 5: Predefined D-LBS zone transmission plan
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IEEE C802.16m-09/3018
Table 2. Predefined D-LBS zone transmission plan.
Allocated
Frequency
resource
D-LBS zone symbol number
0
1
2
3
Frequency
Resource 0
RS 0
RS 3
RS 1
RS 4
Frequency
Resource 1
RS 1
RS 4
RS 2
RS 5
Frequency
Resource 2
RS 2
RS5
RS 0
RS 3
End of the text for distributed D-LBS zone option >>>>>
An ABS/ARS shall transmit the SA-Preamble sequence on the given symbol/carrier set only if its
IDcell matches to corresponding PLG and carrier set as shown in Table 1 or
Table 2.
========================== End of Proposed Text ==============================
9