WO2015042817A1 - Procédés et appareils d'atténuation de cci, de mesure et de rapport de condition d'état de canal, et unité de commande centrale de réseau - Google Patents

Procédés et appareils d'atténuation de cci, de mesure et de rapport de condition d'état de canal, et unité de commande centrale de réseau Download PDF

Info

Publication number
WO2015042817A1
WO2015042817A1 PCT/CN2013/084282 CN2013084282W WO2015042817A1 WO 2015042817 A1 WO2015042817 A1 WO 2015042817A1 CN 2013084282 W CN2013084282 W CN 2013084282W WO 2015042817 A1 WO2015042817 A1 WO 2015042817A1
Authority
WO
WIPO (PCT)
Prior art keywords
cluster
mcl
cell
threshold
user equipment
Prior art date
Application number
PCT/CN2013/084282
Other languages
English (en)
Inventor
Dalin Zhu
Zhennian SUN
Jianfei CAO
Ming Lei
Original Assignee
Nec (China) Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nec (China) Co., Ltd. filed Critical Nec (China) Co., Ltd.
Priority to PCT/CN2013/084282 priority Critical patent/WO2015042817A1/fr
Publication of WO2015042817A1 publication Critical patent/WO2015042817A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/50—Allocation or scheduling criteria for wireless resources
    • H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
    • H04W72/541—Allocation or scheduling criteria for wireless resources based on quality criteria using the level of interference
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/02—Resource partitioning among network components, e.g. reuse partitioning
    • H04W16/10—Dynamic resource partitioning
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/04—Wireless resource allocation
    • H04W72/044—Wireless resource allocation based on the type of the allocated resource
    • H04W72/0446—Resources in time domain, e.g. slots or frames

Definitions

  • Embodiments of the present disclosure generally relate to wireless communication techniques and more particularly relate to a method and apparatus for cross-subframe co-channel interference (CCI) mitigation in a Time Division Duplex (TDD) system, a method and apparatus for channel state condition measuring and reporting and a network central controller.
  • CCI cross-subframe co-channel interference
  • TDD Time Division Duplex
  • LTE Long Term Evolution
  • LTE- Advance system can operate in both Frequency Division Duplex (FDD) mode and
  • Time Division Duplex (TDD) mode Time Division Duplex
  • TD-LTE Time Division LTE
  • UL/DL asymmetrical downlink/uplink
  • a TDD radio frame consists of ten sub frames labeled with 0 to 9. Each of the subframes may be used for DL transmission or UL transmission, or used as a special subframe between the DL period and the UL period.
  • subframes 0 and 5 are used for the DL transmission
  • subframes 2 to 4 and subframes 7 to 9 are used for the UL transmission
  • subframes 1 and 6 are used as special subframes, which are labeled as "D", "U" and
  • the asymmetrical UL/DL resource configuration scheme provides seven UL/DL configurations, from which the base station can select a suitable configuration based on the UL data size and the DL data size. Therefore, this semi-static resource allocation could improve the resource utilization rate. However, since traffic requirements may be fluctuating significantly, in some cases, the semi-static resource allocation may not match instantaneous traffic condition. Hence, a dynamic UL/DL resource configuration has been proposed, wherein a time-scale for reconfiguration is suggested to be tens/hundreds of milliseconds so as to be more adaptive to the traffic requirements.
  • the network may benefit from traffic adaptation in both DL and UL directions.
  • traffic adaptation in both DL and UL directions.
  • the CCI problems become serious.
  • FIG. 2A A scenario of two cells (Cell 0 and Cell 1) illustrated in Fig. 2A will be taken as an example, wherein Cell 0 uses configuration 5 and Cell 1 uses configuration 6.
  • Fig. 2B at subframes 3, 4, 7 and 8 which are designated for DL transmission for Cell 0 and for UL transmission for Cell 1 respectively, the DL transmission from RRUO to user equipment UE 0 will be interfered greatly by the UL transmission Cell 1, i.e., there will be a UE-UE CCI as illustrated in Fig.
  • C-RAN Centralized Radio Access Network
  • RAN Radio Access Network
  • TCO total cost of ownership
  • QoS enhanced system quality of signal
  • BBU Baseband Unit
  • RRU distributed remote radio units
  • CoMP Coordinated Multiple Points
  • elCIC Enhanced Inter-cell Interference Coordination
  • the CCI problem may be tackled by means of cluster-specific cooperative reconfiguration and/or coordinated interference management in the C-RAN.
  • Rl-131879 CAT, 3 GPP RAN1#73, Fukuoka, Japan, May 20th-24th, 2013
  • MCL mutual coupling loss
  • the present disclosure provides a new solution for CCI mitigation in TDD system, so as to solve or at least partially mitigate at least a part of problems in the prior art.
  • a method for CCI mitigation in a TDD system may comprise identifying a cluster-edge user equipment from user equipments in a cluster comprising at least one cell, based on information about large-scale fading for channels allocated to the user equipments; and allocating resource to the cluster-edge user equipment so that at least one of flexible subframes in uplink/downlink configuration is disabled, so as to mitigate the CCI.
  • the method may further comprise performing an adaptive cell clustering based on mutual coupling loss (MCL) with a dynamically adjusted MCL threshold so as to form the cluster comprising at least one cell.
  • MCL mutual coupling loss
  • the performing the adaptive cell clustering may further comprise: obtaining current system performance metrics and system statistics information indicating historical system performance metrics;; determining the MCL threshold based on the current system performance metrics and the system statistics information; and performing a cell clustering based on the determined MCL threshold.
  • a method for channel state condition measurement and reporting in a TDD system may comprise: receiving a measurement indication, which indicate a user equipment to measure channel state condition only on the subframes that are not disabled; measuring the channel state condition on subframes that are not disabled; and reporting the measured channel state condition to a serving node.
  • an apparatus for CCI mitigation in a TDD system may comprise: an user equipment identification unit, configured to identify a cluster-edge user equipment from user equipments in a cluster comprising at least one cell, based on information about large-scale fading for channels allocated to the user equipments; and a resource allocation unit, configured to allocate resource to the cluster-edge user equipment so that at least one of flexible subframes in uplink/downlink configuration is disabled, so as to mitigate the CCI
  • an apparatus for channel state condition measurement and reporting in a TDD system may comprise: measurement indication receiving unit, configured to receive a measurement indication, which indicates a user equipment to measure channel state condition only on the subframes that are not disabled; state condition measuring unit, configured to measure the channel state condition on subframes that are not disabled; and state condition reporting unit, configured to report the measured channel state condition to a serving node.
  • a network central controller comprising: an adaptive cell clustering controller, configured to perform an adaptive cell clustering based on mutual coupling loss (MCL) with a dynamically adjusted MCL threshold to form at least one cluster; an uplink/downlink(UL/DL) reconfiguration controller configured to perform UL/DL reconfiguration operations for the at least one cluster to determine an UL/DL configuration for each of the at least one cluster; a time-domain resource partition controller configured to perform a time-domain resource partition on the UL/DL configuration for each of the at least one cluster for cluster-edge user equipments so that at least one of flexible subframes in UL/DL configuration is disabled, so as to mitigate the CCI.
  • MCL mutual coupling loss
  • a computer-readable storage media with computer program code embodied thereon, the computer program code configured to, when executed, cause an apparatus to perform actions in the method according to any one of embodiments of the first aspect.
  • a computer-readable storage media with computer program code embodied thereon, the computer program code configured to, when executed, cause an apparatus to perform actions in the method according to any one of embodiments of the second aspect.
  • a computer program product comprising a computer-readable storage media according to the sixth aspect.
  • a computer program product comprising a computer-readable storage media according to the seventh aspect.
  • the ICC may be mitigated substantially, and it may benefit from improved cell-average cell-edge performances and enhanced capability in adapting to the asymmetric traffic variations.
  • Figs. 1 schematically illustrates a diagram of UL/DL configurations in LTE TDD system as specified by 3 GPP;
  • FIG. 2A schematically illustrates an example of CCIs in a two-cell scenario
  • FIG. 2B schematically illustrates subframes at which CCI may be caused in the scenario of Fig. 2A ;
  • FIG. 3 schematically illustrates a network in which embodiments of the present disclosure may be implemented
  • FIG. 4 schematically illustrates a flow chart of a method for time-domain resource partition according to an embodiment of the present disclosure
  • FIG. 5 schematically illustrates a diagram of cluster-edge and cluster-center UEs according to an embodiment of the present disclosure
  • Fig. 6 schematically illustrates diagrams of fixed subframes and flexible subframes in UL/DL configurations
  • FIG. 7 schematically illustrates a diagram showing time-domain resource partition according to an embodiment of the present disclosure
  • FIG. 8 schematically illustrates a flow chart of an adaptive cell clustering according to an embodiment of the present disclosure
  • Figs. 9 A to 9G schematically illustrates impact of the MCL thresholds on system performance
  • FIG. 10 schematically illustrates a flow chart of a method a CCI mitigation in TDD according to an embodiment of the present disclosure
  • Fig. 11 schematically illustrates the cumulative density (CDF) of UL geometry SINRs of various MCL thresholds according to an embodiment of the present disclosure
  • Fig. 12 schematically illustrates an exemplary signaling flow diagram for performing time-domain resource allocation according to an embodiment of the present disclosure
  • Fig. 13 schematically illustrates a diagram of channel state condition measuring and reporting according to an embodiment of the present disclosure
  • FIG. 14 schematically illustrates a flow chart of channel state condition measuring an reporting according to an embodiment of the present disclosure
  • FIG. 15 schematically illustrates a network central controller according to an embodiment of the present disclosure
  • Fig. 16 schematically illustrates a block diagram of an apparatus for CCI mitigation in a TDD system according to an embodiment of the present disclosure
  • FIG. 17 schematically illustrates a block diagram of an adaptive clustering cell according to an embodiment of the present disclosure.
  • Fig. 18 schematically illustrates block diagram of an apparatus for channel state condition measuring and reporting according to an embodiment of the present disclosure.
  • each block in the flowcharts or block may represent a module, a program, or a part of code, which contains one or more executable instructions for performing specified logic functions.
  • these blocks are illustrated in particular sequences for performing the steps of the methods, as a matter of fact, they may not necessarily be performed strictly according to the illustrated sequence. For example, they might be performed in reverse sequence or simultaneously, which is dependent on natures of respective operations.
  • block diagrams and/or each block in the flowcharts and a combination of thereof may be implemented by a dedicated hardware-based system for performing specified functions/operations or by a combination of dedicated hardware and computer instructions.
  • a user equipment may refer to a terminal, a Mobile Terminal (MT), a Subscriber Station (SS), a Portable Subscriber Station (PSS), Mobile Station (MS), or an Access Terminal (AT), and some or all of the functions of the UE, the terminal, the MT, the SS, the PSS, the MS, or the AT may be included.
  • MT Mobile Terminal
  • PSS Portable Subscriber Station
  • MS Mobile Station
  • AT Access Terminal
  • BS may represent, e.g., a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a radio header (RH), a remote radio head (RRH), a relay, or a low power node such as a femto, a pico, and so on.
  • NodeB or NB node B
  • eNodeB or eNB evolved NodeB
  • RH radio header
  • RRH remote radio head
  • relay or a low power node such as a femto, a pico, and so on.
  • a cloud based TDD heterogeneous networks in which embodiments of the present disclosure may be implemented.
  • the centralized RAN Radio Access Network
  • a RRU is comparable to a cell and installed at each local site with only radio frequency (RF) front-end functionalities.
  • All RRUs are connected with a central control unit (CCU) through an optical fiber network.
  • All the processing units/capabilities are pooled in BBU pools at the CCUs. Due to such a centralized RAN architecture, it provides a possibility to formulate the UL/DL reconfiguration as the corporative control and implemented efficiently in the present disclosure.
  • TRP time-domain resource partition
  • TRP Time-domain Resource Partition
  • Fig. 4 schematically illustrates a flow chart of a method for time-domain resource partition according to an embodiment of the present disclosure.
  • a cluster-edge user equipment is identified from user equipments in a cluster comprising at least one cell, based on information about large-scale fading for channels allocated to the user equipments.
  • UEs in a cluster may be categorized into “cluster-central UEs” and “cluster-edge UEs.”
  • the cluster-central UEs means UEs that are severed in a good channel quality and suffer from little interference in a sense of long term
  • the cluster-edge UEs means UEs that suffer a lot from interference and are severed in a bad channel quality in a long term.
  • the cluster-edge UEs may be identified based on information that may reflect a long term channel quality.
  • information about large-scale fading for channels allocated to the user equipments is used. The identifying may be performed by comparing the information about large-scale fading for channels allocated to the user equipments and a channel fading threshold.
  • the appropriate information about large-scale fading for channels may comprise geometry signal to interference-plus-noise ratio (SINR), coupling loss, and so on.
  • SINR geometry signal to interference-plus-noise ratio
  • the geometry SINR of UE i in cell j in a cluster may be calculated as
  • Equation (1) wherein P j denotes the transmit power of the transmitter of UE I;, Ij denotes the set of all active UEs of cell j; denotes the path gain from UE i to its serving RRU j; which is linear and in terms of power; M denotes the set of all formed cell clusters; M' denotes the cell cluster that cell j is involved in, wherein M' ⁇ M; g(p,q ) denotes the transmission direction between UE p and RRU q.
  • the g(p,q) may be expressed as follows q DL transmission from RRU q to UE p
  • a target SINR threshold which may denoted as & .
  • a cluster-edge UE may be identified.
  • 5%-percentile SINR threshold is only an example and other percentile SINR threshold may also be feasible, which depends on practical implementation of the network. Actually, the percentile SINR threshold can be determined by some measured values such as High Interference Indicator (HII), Overload Indicator (OI), Relative Narrowband Transmit Power (RNTP) and etc.
  • step S402 resource allocation is performed to allocate resource for the cluster-edge user equipment so that at least one of flexible subframes in uplink/downlink configuration is disabled, so as to mitigate the CCI.
  • subframes may be divided into flexible subframes and fixed subframes.
  • a flexible subframe means a subframe that may be used to transmit both UL signals and DL signals and the fixed subframe denotes a subframe that is fixed to transmit one of UL signals or DL signals.
  • the flexible subframes and the fixed subframes will be described with reference to Fig. 6.
  • subframes 0 and 5 are used to transmit DL signals
  • subframe 1 is a special subframe which may be also considered to transmit DL signals
  • subframe 6 is used to transmit DL signals or is designed as a special subframe and thus it may be consider to transmit DL signals.
  • subframes 3 to 4 and 7 to 9 may transmit both UL signals and DL signals.
  • subframe 0 to 2 and 5 to 6 are called as fixed subframes
  • subframes 3 to 4 and 7 to 9 may be called as flexible subframes.
  • time-domain resource partition "TRP” time-domain resource partition
  • Fig. 7 An example about how to schedule different types of UEs in different types of subframes will be described with reference to Fig. 7.
  • Fig. 7 there are four cell clusters, i.e., cell cluster-I, cell cluster-II, cell cluster- Ill, and cell cluster-IV.
  • cell cluster-IV comprising only cell is taken as an example.
  • similar procedure can be easily extended to the case that a cluster contains a plurality of cells.
  • UE 0 is identified as a cluster-edge UE, and both UE 1 and UE 2 are determined as cluster-center UEs.
  • the three UEs may all be scheduled in fixed subframes while only the cluster-center UEs, i.e., UE 1 and UE 2, can be scheduled in the flexible subframes. That is to say, for the cluster-edge UE, flexible subframes are disabled.
  • cluster-center UEs usually have a good channel quality and thus CCI will not bring about a significant affect.
  • CCI will not bring about a significant affect.
  • cluster-edge UEs which have a bad channel quality, they may suffer from the CCI a lot.
  • the TRP method may be performed only if the time-domain resource partition is set as enabled.
  • ACC adaptive cell clustering
  • step S801 it may obtain current system performance metrics and system statistics information indicating historical system performance metrics.
  • three performance metrics indicators are used, i.e., (a) UL cell-edge packet throughput; (b) sum cell-average packet throughput of DL transmission and UL transmission; and (c) an indicator representing suitability of the cell clustering.
  • the UL cell-edge packet throughput may be denoted as Ri and it may be defined as the UL cell-edge packet throughput observed after z ' -th cell clustering.
  • the sum cell-average packet throughput of DL transmission and UL transmission may also be denoted as Q and defined as the sum cell-average packet throughput after z ' -th cell clustering. More specifically, the sum cell-average packet throughput of DL transmission and UL transmission Q may be represented by
  • Equation (4) wherein Cf denotes the cell-average packet throughput of DL transmission; and u denotes the cell-average packet throughput of UL transmission.
  • the indicator representing suitability of the cell clustering may be represented, for example, by the difference between the real traffic demands and the actually transmitted packets in both DL and UL directions. If Bf k and B" k respectively denotes the total number of packets arrived in cell /Vs DL and UL buffers before (z ' +i)-th clustering process, and P t D k and P" k respectively denotes the total number of packets that have been processed in cell /Vs DL and UL transmissions before (z+i)-th clustering process, then the indicator representing suitability of the cell clustering may be represented for exam le by
  • step S802 it may determine the MCL threshold based on the system statistics information and the current performance metrics.
  • the MCL threshold may be used rather than one single MCL threshold.
  • the inventors have made some simulations to study the effect of the MCL thresholds on the cluster size and the system performance. Simulations results are illustrated in Figs. 9A to 9G. From these simulation results, it may be seen that the mean size of cell clusters is mainly determined by the MCL threshold based on which the cell clustering is performed. Moreover, with the increasing MCL threshold, the cell-average sum DL and UL throughput, the cell-average DL throughput, the cell-edge DL throughput will decrease the cell-edge UL throughput will increase, and the cell-average UL throughput will increase first and then decrease while the squared error of DL.DL ration will increase gradually.
  • a set of potential MCL thresholds may be constructed as follows:
  • n MC L ⁇ 40, 50, 60,70, 140 ⁇ dB
  • one of the predetermined MCL thresholds will be selected by the central controller of the network based on system statistics information and current system performance metric.
  • an indicator ⁇ (x,y,z) which may be represented as follows: 0 Remain the MCL threshold
  • Equation (7) wherein parameters x, y and z denotes the above mentioned system performance metrics Ri, Ci and Q t respectively.
  • the value of indicator ⁇ (x,y,z) may be determined based on decision rules or triggering events.
  • the system capability in adapting to the asymmetric traffic demands has a higher priority than the cell-edge performance; if the decision as to how to adjust the MCL threshold can not be made by simply comparing the traffic adaptation capability, the cell-edge performance will play a role in determining the appropriate MCL threshold. On the other hand, if the performance indicators of interest are better than previously measured performance statistics, conservative method is applied which remains the MCL threshold and keep it as it is.
  • the MCL threshold at (z ' +7)-th cell clustering would be increased by one index, i.e., the value should be lOOdB.
  • step S803 it may perform the cell clustering based on the determined MCL threshold.
  • the cell clustering can be conducted either in a dynamic manner or a semi-static manner.
  • the time-scale or time period for cell clustering can be in the order of millisecond, second, minute, hour and etc. It should be noted that the selection of appropriate time-scale for adaptive cell clustering plays an important role. If the time-scale is too small, the accuracy of the collected system statistics information may not be guaranteed; on the other hand, if the time-scale is too large, the system capability in adapting to the performance variations may be compromised. Moreover, the selection of appropriate time-scale should avoid disruptive performance jumps due to the adaptation.
  • the cell clustering may be performed in a dynamic manner, wherein the time-scale is in the order of millisecond, or more specifically, in the order of 200ms or even more such as 400ms, 600ms, 800ms or even 1000ms.
  • the cell cluster may start by randomly selecting RRUs as anchor points. Other RRUs that have smaller MCL than the predetermined MCL threshold to the anchor RRUs would be categorized into the same clusters associated with the anchor RRUs.
  • the clusters are not overlapped with each other (i. e., disjoint).
  • an exemplary pseudo-code of the MCL-based cell clustering algorithm is presented as follows:
  • ⁇ denotes the MCL threshold
  • i ⁇ c denotes the set contains all RRUs of interest
  • N c represents the total number of Us contained in the set i ⁇ c
  • Ac denotes the set of all cell clusters
  • N TC denotes the number of cell clusters
  • Si ⁇ Ac represents the cell cluster that is anchored at RRU;.
  • the cell clustering may perform a cluster-specific reconfiguration, which means that the UL/DL configurations are no longer determined with respect to an individual cell, but are chosen on the basis of cell clusters.
  • the cluster-specific reconfiguration refers to the scheme that the same UL/DL configuration is determined for a cell cluster for a purpose of intra-cluster CCI elimination; on the other hand, the UL/DL configurations employed by different clusters could be different in a subframe for asymmetric traffic adaptation. More specifically, the ratio of the accumulated buffered DL and UL data volumes regarding a cell cluster is first calculated; then, the UL/DL configuration that has the closest UL/DL ratio to the calculated ratio would be selected as reconfiguration for the cell cluster. Straightforwardly, the performance of the cluster-specific reconfiguration highly relies on the cell clustering outcomes. In fact, in the present disclosure, the cell-specific reconfiguration may be considered as one special case of the cluster-specific reconfiguration when the cluster contains only one cell.
  • the cluster-specific reconfiguration whether to perform the proposed TRP or not is also an implementation problem depending on practical requirements. For example, it may assume that the TRP is always performed. Or alternatively, the TPR are performed only when the TRP is set as enabled.
  • Fig. 10 schematically illustrates a method of CCI mitigation with a combined ACC and TRP according to an embodiment of the present disclosure.
  • step SI 001 it determines whether the time-scale for cell clustering is satisfied. If no, the procedure goes back to "start"; otherwise, the procedure proceeds into step SI 002 at which it is determined whether the ACC is enabled. If the ACC is not enabled, the procedure enters step SI 004 and the MCL-based cell clustering is performed for example with a predetermined MCL threshold, instead of a dynamically adjusted MCL threshold. If the ACC is enabled, the procedure enters step SI 003, wherein the MCL threshold is adjusted dynamically based on the method as described wither reference to Fig.
  • the MCL-based cell clustering is performed based on the adjusted MCL threshold.
  • a cluster-specific dynamic UL/DL reconfiguration is performed on the cell clusters so as to determine the UL/DL configuration for each of the cell clusters.
  • the target SINR threshold for identifying the cell-center UEs and the cell-edge UEs will vary with the adjusted MCL threshold when, for example, a percentile geometry SINR is set as the target SINR threshold. This means for different MCL thresholds, it may obtain different cell clusters and the target SINR threshold corresponding to the percentile geometry SINR will also change.
  • Fig. 11 schematically illustrates a CDF of UL geometry SINRs of various MCL thresholds. From the figure, it is clear that the target SINR threshold varies with respect to the MCL thresholds. In other word, the target SINR threshold will vary during the process of ACC.
  • Fig. 12 schematically illustrates an exemplary signaling flow diagram for performing time-domain resource allocation according to an embodiment of the present disclosure.
  • a cell clustering adaption decision will be sent from the BBU pool to the RRU to inform the RRU its cell clustering adaption decision. Then, it will further send a UL/DL configuration adaption decision to the RRU at step S1202, so as to notify the RRUs of the UL/DL configuration for the cell cluster.
  • a time-domain resource partition decision will also be transmitted to the RRU at step SI 203 so that the RRU can learn whether the TRP is enabled.
  • the RRU may update its configuration at step S1204, and more specifically, it may perform the synchronization, change RF and other necessary operations in accordance with the BBU pool's decisions. Then, the RRU may transmit with updated configuration at step SI 205. Besides, updated configurations will be also be transmitted to the UE from the BBU pool at S1206. After receiving the updated configurations, the UE may respond at step S1207 so as to change RF, detect primary synchronization sequence/ secondary synchronization sequence (PSS/SSS), perform RRM measurements and etc. Afterwards, at step S1208, a random access channel (RACH) procedure may be performed between the UE and the RRU to complete the initialization procedure.
  • RACH random access channel
  • the RRU will use, for example, RRC signaling or a broadcast or a multicast approach to notify the UE of the adaptive cell clustering results.
  • the UE will measure channel state conditions such as RRM/CSI and so on, and then transmit the measurement report to the RRU at step S1210.
  • the communication may be performed between the UE and the RRU with updated configurations.
  • Fig. 13 schematically illustrates a diagram of channel state condition measuring and reporting according to an embodiment of the present disclosure. As illustrated, for cluster-center UEs for which both fixed subframes and flexible subframes are enabled, the channel state condition measuring and reporting may be performed as usual, i.e.
  • channel state condition (such as CSI, CQI and SRS)for both fixed subframes and flexible subframes are measured and reported for using by a serving node. That is to say, both channel state condition CSIo, CQIo and SRSo and CSIi, CQIi and SRSi for fixed subframes and flexible subframes will be used. However, for the cluster-edge UEs for which only fixed subframes are enabled, only the channel state condition for fixed subframes are measured and reported, and only channel state condition CSIo, CQIo and SRSo for fixed subframes will be used.
  • Fig. 14 schematically illustrates a flow chart of channel state condition measurement according to an embodiment of the present disclosure.
  • a channel state condition measurement indication is received.
  • the indication indicates a UE to measure channel state condition only on the subframes that are not disabled.
  • the UE measures the channel state condition on subframes that are not disabled.
  • the subframes that are disabled comprise at least one of flexible subframes in uplink/downlink configuration and preferably, all of flexible subframes in uplink/downlink configuration are disabled.
  • the flexible subframes in UL/DL configuration comprise subframe 3, 4, 7, 8 and 9.
  • the channel state condition may comprise for example channel station indicator, channel quality indicator, and sounding reference signal.
  • the UE may report the measured channel state condition to the RRU.
  • Fig. 15 schematically illustrates a network central controller according to an embodiment of the present disclosure.
  • the network central controller 1500 may comprise ACC controller 1510, a UL/DL reconfiguration controller 1520, a T P controller 1530 and a storage device 1540.
  • the ACC controller 1510 may be configured to perform an adaptive cell clustering based on mutual coupling loss (MCL) with a dynamically adjusted MCL threshold to form at least one cluster.
  • MCL mutual coupling loss
  • the UL/DL reconfiguration controller 1520 is configured to perform of UL/DL reconfiguration operations for the at least one cluster to determine an UL/DL configuration for each of the at least one cluster.
  • the TRP controller 1530 may be configured to control perform a time-domain resource partition on the UL/DL configuration for each of the at least one cluster for cluster-edge user equipments so that at least one of flexible subframes in UL/DL configuration is disabled, so as to mitigate the CCI.
  • the ACC controller 1510 may further comprise: an adaptation timer 1511, an ACC performance metrics computation module 1512, a triggering module 1513, and a clustering performing module 1514.
  • the adaptation timer 1511 is a timer configured to control time period of an adaptive cell clustering operation. The adaptation time 1511 will monitor whether the time-scale for the ACC is satisfied or not. If the time-scale for UL/DL reconfiguration is satisfied, it will trigger the ACC process.
  • the ACC performance metrics computation module 1512 configured to compute current system performance metrics based on measurements stored in a statistics information and measurements storage 1540.
  • the triggering module 1513 configured to determine the MCL threshold based on the system statistics information stored in the statistics information and measurements storage 1540 and the current system performance metrics.
  • the triggering module 1513 will make the adaption decision by selecting an appropriate MCL threshold. Then a clustering performing module 1514 may be configured to perform a cell clustering based on the determined MCL threshold. The cell clustering results will be notified to both the UL/DL reconfiguration controller 1520 and the T P controller 1530.
  • the UL/DL reconfiguration controller 1520 further comprises a reconfiguration timer 1521, a reconfiguration performance metric computation module 1522, and a UL/DL configuration performing module 1524.
  • the reconfiguration timer is a configurable period of time.
  • the performance metrics computation module 1521 may be configured to control time period of an UL/DL reconfiguration operation. Specifically, the reconfiguration time 1521 monitors whether the time-scale for UL/DL reconfiguration is satisfied or not. If the time-scale for reconfiguration is satisfied, it will trigger the reconfiguration process.
  • the UL/DL reconfiguration performing module 1524 may be configured to perform the UL/DL reconfiguration operation based on the current system performance metrics to determine the UL/DL configuration for each of the at least one cluster.
  • the TRP controller 1530 may further comprise a TRP performance metrics computation module 1532 and a scheduling decision module 1534.
  • the performance metrics computation module 1532 may be configured to obtain information about large-scale fading for channels allocated to the user equipments so as to identify cluster-edge user equipments in each of the at least one cluster, from the performance information stored in the SSI and measurements storage device 1540.
  • the scheduling decision module 1534 may be configured to allocate resource to the cluster-edge user equipment so that at least one of flexible subframes in uplink/downlink configuration is disabled, so as to mitigate the CCI.
  • the apparatus may comprise a user equipment identification unit 1610 and a resource allocation unit 1620.
  • the user equipment identification unit 1610 may be configured to identify a cluster-edge user equipment from user equipments in a cluster comprising at least one cell, based on information about large-scale fading for channels allocated to the user equipments.
  • the resource allocation unit 1620 may be configured to allocate resource to the cluster-edge user equipment so that at least one of flexible subframes in uplink/downlink configuration is disabled, so as to mitigate the CCI.
  • the user equipment identification unit 1610 may be further configured to identify a cluster-edge user equipment by comparing the information about large-scale fading for channels allocated to the user equipments and a channel fading threshold.
  • the information about large-scale fading may comprise one or more of: coupling loss; geometry signal to interference-plus-noise ratio; and geographical locations of the user equipments.
  • the flexible subframes in uplink/downlink configuration may comprise subframe 3, 4, 7, 8 and 9.
  • the user equipment identification unit 1610 and the resource allocation unit 1620 may function when time-domain resource partition is set as enabled.
  • the apparatus 1600 may further comprise an adaptive cell clustering unit 1630, configured to perform an adaptive cell clustering based on mutual coupling loss (MCL) with a dynamically adjusted MCL threshold, so as to form the cluster comprising at least one cell.
  • MCL mutual coupling loss
  • the adaptive cell clustering unit 1630 may further comprise: an information obtaining unit 1631, configured to obtain current system performance metrics and system statistics information indicating historical system performance metrics; a threshold determination unit 1632, configured to determine the MCL threshold based on the current system performance metrics and the system statistics information; and a clustering performing unit 1633, configured to perform cell clustering based on the determined MCL threshold.
  • the threshold determination unit 1632 may be further configured to determine whether to increase, maintain or decrease an old MCL threshold based on the current system performance metrics and the system statistics information; and select, from a set of MCL thresholds containing a plurality of potential MCL thresholds, a new MCL threshold as the determined MCL threshold based on the determining and the old MCL threshold.
  • the system performance metrics comprises: UL cell-edge packet throughput; sum cell-average packet throughput of DL transmission and UL transmission; an indicator representing suitability of the cell clustering.
  • the adaptive cell clustering unit 1630 may function when the adaptive cell clustering is set as enabled.
  • the channel fading threshold may vary with the dynamically adjusted MCL threshold.
  • a measurement indication sending unit 1640 configured to send a measurement indication to the cluster-edge user equipment to indicate the cluster-edge user equipment to measure channel state condition only on the subframes that are not disabled.
  • the apparatus 1800 may comprise a measurement indication receiving unit 1810, a state condition measuring unit 1820, and a state condition reporting unit 1830.
  • the measurement indication receiving unit 1810 may be configured to receive a measurement indication, which indicates a user equipment to measure channel state condition only on the subframes that are not disabled.
  • the state condition measuring unit 1820 may be configured to measure the channel state condition on subframes that are not disabled.
  • the state condition reporting unit 1830 may be configured to report the measured channel state condition to a serving node.
  • the subframes that are disabled may comprise at least one of flexible sub frames in uplink/downlink configuration.
  • the flexible sub frames in uplink/downlink configuration comprise subframe 3, 4, 7, 8 and 9.
  • all of flexible subframes in uplink/downlink configuration may be disabled.
  • the channel state condition comprises one or more of channel station indicator, channel quality indicator, and sounding reference signal.
  • the CCI may be mitigated substantially, and it may benefit from improved cell-average cell-edge performances and enhanced capability in adapting to the asymmetric traffic variations.
  • an exemplary set of potential MCL thresholds are used to describe the embodiments of the present disclosure.
  • the present disclosure is not limited thereto, the number of MCL thresholds and their step size may vary dependent on practical deployment.
  • the proposed cell clustering procedure is performed in a centralized manner. However, it may also be performed in a distributed way and in such a case, necessary performance metrics and SSI may be exchanged between relevant base stations so that a joint decision may be made.
  • the proposed cell clustering is evaluated and incorporated into the cluster-specific reconfiguration; however, it should be noted that the proposed cell clustering may also be transparent to the radio access technologies that are employed as long as necessary SSI and/or measurements can be obtained.
  • the UL geometry SIN s are used to categorize UEs into cluster-center UEs and cluster-edge UEs. Nevertheless, the skilled in the art should appreciate that any other suitable interference indicators such as sub-band CQIs, pure interference levels may also be used.
  • the target SIN threshold is set as 5%-percentile geometry SINRs of all active UEs, the skilled in the art will note that different methods of determining the target SINR threshold may be employed as well such as those method used in FFR.
  • the proposed TRP is used to mitigate cluster boundary effect.
  • the proposed TRP may also be performed by incorporating into other CCIS methods.
  • the TDD-LTE system is taken as an example, however, it is also possible to apply the solution as proposed to any other appropriate TDD system.
  • embodiments in which all flexible subframe are disabled for cluster-edge UEs are described in details, however, the skilled in the art may understand that it may also benefit if at least part of the flexible subframes are disabled for cluster -edge UEs.
  • present invention has been described with specific algorithm, but the present disclosure is not limited thereto, any other suitable algorithm may also be employed.
  • the present disclosure may be embodied in an apparatus, a method, or a computer program product.
  • the various exemplary embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof.
  • some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the disclosure is not limited thereto.

Landscapes

  • Engineering & Computer Science (AREA)
  • Quality & Reliability (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

La présente invention concerne, dans des modes de réalisation, un procédé et un appareil d'atténuation de brouillage dans le même canal (CCI) de sous-trames croisées dans un système duplex à répartition dans le temps (TDD). Le procédé peut consister à: identifier un équipement utilisateur en bord de grappe à partir d'équipements utilisateur dans une grappe comportant au moins une cellule, sur la base d'informations d'affaiblissement à grande échelle pour des canaux attribués aux équipements utilisateur; et attribuer des ressources à l'équipement utilisateur en bord de grappe de sorte qu'au moins une des sous-trames souples de la configuration de liaison montante/liaison descendante (UL/DL) est désactivée, afin d'atténuer le CCI. De plus, dans certains modes de réalisation de la présente invention, ledit procédé peut en outre effectuer un regroupement de cellules adaptatif sur la base de la perte de couplage mutuel (MCL) à l'aide d'un seuil de MCL dynamiquement réglé de façon à améliorer le regroupement, puis atténuer encore plus le CCI. Grâce aux modes de réalisation de la présente invention, le CCI peut être atténué sensiblement et il peut bénéficier de performances améliorées en périphérie de cellule et en moyenne de cellule et de capacités renforcées d'adaptation aux variations de trafic asymétriques.
PCT/CN2013/084282 2013-09-26 2013-09-26 Procédés et appareils d'atténuation de cci, de mesure et de rapport de condition d'état de canal, et unité de commande centrale de réseau WO2015042817A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2013/084282 WO2015042817A1 (fr) 2013-09-26 2013-09-26 Procédés et appareils d'atténuation de cci, de mesure et de rapport de condition d'état de canal, et unité de commande centrale de réseau

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2013/084282 WO2015042817A1 (fr) 2013-09-26 2013-09-26 Procédés et appareils d'atténuation de cci, de mesure et de rapport de condition d'état de canal, et unité de commande centrale de réseau

Publications (1)

Publication Number Publication Date
WO2015042817A1 true WO2015042817A1 (fr) 2015-04-02

Family

ID=52741773

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2013/084282 WO2015042817A1 (fr) 2013-09-26 2013-09-26 Procédés et appareils d'atténuation de cci, de mesure et de rapport de condition d'état de canal, et unité de commande centrale de réseau

Country Status (1)

Country Link
WO (1) WO2015042817A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110337133A (zh) * 2016-01-22 2019-10-15 华为技术有限公司 通信方法、通信装置和通信系统
CN111512662A (zh) * 2017-10-13 2020-08-07 上海诺基亚贝尔股份有限公司 方法、系统和装置

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103068050A (zh) * 2012-12-25 2013-04-24 上海无线通信研究中心 一种时分双工系统中基于干扰感知的上下行时隙资源配置方法
WO2013056445A1 (fr) * 2011-10-20 2013-04-25 Renesas Mobile Corporation Procédé, appareil et produit programme d'ordinateur pour une configuration tdd souple
CN103220677A (zh) * 2013-05-09 2013-07-24 东莞宇龙通信科技有限公司 用于小区簇的干扰消除方法和基站

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013056445A1 (fr) * 2011-10-20 2013-04-25 Renesas Mobile Corporation Procédé, appareil et produit programme d'ordinateur pour une configuration tdd souple
CN103068050A (zh) * 2012-12-25 2013-04-24 上海无线通信研究中心 一种时分双工系统中基于干扰感知的上下行时隙资源配置方法
CN103220677A (zh) * 2013-05-09 2013-07-24 东莞宇龙通信科技有限公司 用于小区簇的干扰消除方法和基站

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110337133A (zh) * 2016-01-22 2019-10-15 华为技术有限公司 通信方法、通信装置和通信系统
CN110337133B (zh) * 2016-01-22 2020-12-25 华为技术有限公司 通信方法、通信装置和通信系统
US11039418B2 (en) 2016-01-22 2021-06-15 Huawei Technologies Co., Ltd. Method for processing system message, network device, and user terminal
CN111512662A (zh) * 2017-10-13 2020-08-07 上海诺基亚贝尔股份有限公司 方法、系统和装置
CN111512662B (zh) * 2017-10-13 2024-01-02 上海诺基亚贝尔股份有限公司 用于标识通信系统内的干扰飞行器用户设备的方法、系统和装置

Similar Documents

Publication Publication Date Title
JP7468576B2 (ja) 基地局、ｕｅ及び方法
US11284355B2 (en) Interference measurement method and related device
EP2981143B1 (fr) Procédé de suppression de brouillage, dispositif associé et système
EP2529587B1 (fr) Procédé et agencement dans un système de communication sans fil
JP6454014B2 (ja) 秘匿ノード検出
WO2020144624A1 (fr) Configuration et communication de rapport de mesurage de cli
JP5202544B2 (ja) 上りリンクでチャネル品質情報を報告する方法、並びにその方法に好適な基地局およびユーザ装置
US9942012B2 (en) Carrier allocation method, user equipment, and base station
EP2579660A1 (fr) Procédé de spécification de ressources radio, système de communications radio, état de base radio et programme
US9432159B2 (en) Method, apparatus and computer program for providing sounding reference signals for coordinated multipoint transmissions
US20140192744A1 (en) Method and apparatus for coordinated multi-node transmission
KR102048760B1 (ko) 무선 통신 시스템에서 간섭 조정을 위한 시스템 및 방법
US20110170438A1 (en) Radio communications system, base station, user apparatus, and method
WO2014113941A1 (fr) Allocation de ressources dans un réseau de radiocommunication
US9954634B2 (en) Wireless communication method, and wireless communication apparatus
US20190098637A1 (en) Improving communication quality between a wireless communication node; and wireless communication devices
US20220039133A1 (en) Centralized intercell interference coordination
CN108886463B (zh) 用于使网络节点能够在电信网络中执行无线电操作任务的方法、系统和装置
EP2730139A1 (fr) Procédés et agencements permettant de traiter une transmission en liaison descendante dans un réseau cellulaire
WO2015042817A1 (fr) Procédés et appareils d'atténuation de cci, de mesure et de rapport de condition d'état de canal, et unité de commande centrale de réseau
JP2012249319A (ja) 移動無線通信システムにおけるパイロット配置方法及びこれを適用する送受信装置
JP2012253486A (ja) 無線通信装置及び無線通信プログラム
WO2014179351A1 (fr) Procédé et système de coordination de brouillage dans un système lte-tdd sans fil

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13894783

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13894783

Country of ref document: EP

Kind code of ref document: A1