WG7051 issue #1
Title: Additional Terms and Definition
Source: GSI 은세영
Comment: 3 장에 terms and definitions 가 있기는 하나 SW 에 관련된 용어들만
정의가 되어있는데 문서 초반에 문서에 나오는 모든 약어가 정리가 되어 있으면
어떨가 하는 의견입니다.
3. Term and Definition
1) Beamforming Network (BFN)
: BFNs combine signals from small antennas into a pattern that is more directional than
each antenna by itself because of array factor.
2) Common Object Request Broker Architecture (CORBA)
: An OMG distributed computing platform specification that is independent of
: A component can always be considered an autonomous unit within a system or
subsystem. It has one or more ports, and its internals are hidden and inaccessible other
than as provided by its interfaces. A component represents a modular part of a system
that encapsulates its contents and whose manifestation is replaceable within its
environment. A component exposes a set of ports that define the component
specification in terms of provided and required interfaces. As such, a component serves
as a type, whose conformance is defined by these provided and required interfaces
(encompassing both their static as well as dynamic semantics).
: The realization of certain functionality through a set of well defined interfaces.
: A characteristic or feature that someone or something has.
6) Interface Definition Language (IDL)
: An OMG and ISO standard language for specifying interfaces and associated data
: A formal specification of the function, structure and/or behavior of an application or
8) Model Driven Architecture (MDA)
: An approach to IT system specification that separates the specification of functionality
from the specification of the implementation of that functionality on a specific
: A set of subsystems/technologies that provide a coherent set of functionality through
interfaces and specified usage patterns that any subsystem that depends on the platform
can use without concern for the details of how the functionality provided by the platform
10) Platform Independent Model (PIM)
: A model of a subsystem that contains no information specific to the platform, or the
technology that is used to realize it.
11) Platform Specific Model (PSM)
: A model of a subsystem that includes information about the specific technology that is
used in the realization of it on a specific platform, and hence possibly contains elements
that are specific to the platform.
12) Unified Modeling Language (UML)
: An OMG standard language for specifying the structure and behavior of systems. The
standard defines an abstract syntax and a graphical concrete syntax.
13) UML Profile
: A standardized set of extensions and constraints that tailors UML to particular use.
14) Extensible Markup Language (XML)
: A widely-used computer language for creating and designing pages on the World Wide
Web, and for defining other languages with more specialized purposes.
15) Frame Error Rate (FER)
: Ratio of data received with errors to total data received. It is used to determine the
quality of a signal connection. If the FER is too high (too many errors), the connection
may be dropped.
16) Direction of Arrival (DOA)
: The direction from which usually a propagating wave arrives at a point, where usually a set of
sensors are located.
WG7051 issue #2
Title: Description for MU-MIMO/Cooperative MIMO
Source: GSI 은세영
Comment: introduction 에 Smart antenna 의 분류 언급되었고 실제 SW
architecture 에도 반영이 되어있는데요 최근 LTE 등에서 언급되고 있는 분류
(Single User MIMO, Multi User MIMO, Cooperative MIMO 등)는 의미가 없는지요?
1.4 Multiple Input Multiple Output (MIMO)
In radio, multiple-input and multiple-output (MIMO) is the use of multiple antennas at both the
transmitter and receiver to improve communication performance. It is one of several forms of
smart antenna technology. MIMO technology has attracted attention in wireless communications,
because it offers significant increases in data throughput and link range without additional
bandwidth or transmit power. It achieves this by higher spectral efficiency and link reliability or
diversity. MIMO can be sub-divided into two categories, SU-MIMO or MU-MIMO.
There are two different types of MIMO schemes: one uses spatial multiplexing to
enhance data rate for a given bandwidth (thus, the spectral efficiency) and the other uses
space time coding using diversity combining techniques to combat fading. In the
multiplexing scheme, data is serial to parallel converted and transmitted simultaneously
over multiple antenna elements. The receiver also uses multiple antenna elements to
receive the signal and applies a maximum likelihood (ML) algorithm to retrieve the
simultaneously transmitted symbols. One key assumption in this case is that the
propagation environment has to provide rich scattering; in other words, the propagation
channel has to include a large number of scattering objects that will generate
independent fading at the antenna elements. In the case of space-time coding, symbols
to be transmitted are coded over multiple antennas and symbol time durations in such a
way that the receiver can easily regenerate the transmitted signals by doing a linear
processing on received signal. The space-time codes rely on the orthogonality present in
the coded symbols for proper detection, and additionally they require the fading to be
independent between the antenna elements for best performance results.
Single-user MIMO (SU-MIMO) communication promises large gains for both channel
capacity and reliability, essentially via the use of the space-time codes (diversity gain
oriented) combined with the spatial multiplexed transmission (rate maximization
oriented). In such a single-user view of MIMO systems, the extra spatial degrees of
freedom (DoF) brought by the use of multiple antennas are exploited to expand the
dimensions available for signal processing and detection, thus acting mainly as a physical
(PHY) layer performance booster. In this approach, the link layer protocols for multiple
accesses (uplink and downlink) indirectly reap the performance benefits of MIMO
antennas in the form of greater per-user rates or more reliable channel quality despite
not requiring full awareness of the MIMO capability.
Multi-user MIMO (MU-MIMO) is a set of advanced MIMO technologies that exploit the availability
of multiple independent radio terminals in order to enhance the communication capabilities of
each individual terminal. Multi-user MIMO algorithms are developed to enhance MIMO systems
when the number of users, or connections, numbers greater than one. The situation with MU-
MIMO techniques is radically different as these techniques imply the use of spatial sharing of the
channel by the users, thus deeply affecting the design of the multiple access protocol. In spatial
multiple access, the resulting multiuser interference is handled by the multiple antennas, which, in
addition to providing per-link diversity, also give the DoF necessary for spatial separation of the
users. The most substantial cost is due to the fact that MU-MIMO requires channel state
information at transmitter (CSIT) to properly serve the spatially multiplexed users. CSIT, while not
essential in SU-MIMO communication channels, is of critical importance to most downlink
multiuser precoding techniques. The need for CSIT feedback places a significant burden on uplink
capacity in most systems, exacerbated in systems with wideband communication or high mobility.
1.4.3 Cooperative MIMO
Cooperative MIMO is a technique useful for future cellular networks which consider
wireless mesh networking or wireless ad-hoc networking. In wireless ad-hoc networks,
multiple transmit nodes communicate with multiple receive nodes. To optimize the
capacity of Ad-hoc channels, MIMO concepts and techniques can be applied to multiple
links between the transmit and receive node clusters. Contrasted to multiple antennas in
a single-user MIMO transceiver, participating nodes and their antennas are located in a
distributed manner. So, to achieve the capacity of this network, techniques to manage
distributed radio resources are essential. Strategies such as autonomous interference
cognition, node cooperation, and network coding with dirty paper coding (DPC) have
been suggested as solutions to optimize wireless network capacity.
WG7051 issue #3
Title: Additional property for supporting CSI feedback
Source: HYU 현승헌
Comment: MU-MIMO, Cooperative MIMO 의 다운링크 빔포밍에 필요한 CSI
feedback 을 지원하기 위한 property 들이 요구됨.
The CSIFeedBack attribute represents the channel state information which is used for
adaptive transmission such as transmit beamforming/precoding in MIMO and