WO2016088719A1 - 上りリンク干渉低減方法、及び基地局 - Google Patents
上りリンク干渉低減方法、及び基地局 Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
- H04J11/0023—Interference mitigation or co-ordination
- H04J11/0026—Interference mitigation or co-ordination of multi-user interference
- H04J11/0036—Interference mitigation or co-ordination of multi-user interference at the receiver
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/20—Control channels or signalling for resource management
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
- H04J11/0023—Interference mitigation or co-ordination
- H04J11/005—Interference mitigation or co-ordination of intercell interference
- H04J11/0056—Inter-base station aspects
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
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- H04W—WIRELESS COMMUNICATION NETWORKS
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- 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
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04W92/00—Interfaces specially adapted for wireless communication networks
- H04W92/16—Interfaces between hierarchically similar devices
- H04W92/20—Interfaces between hierarchically similar devices between access points
Definitions
- the present invention relates to a technique for performing uplink interference reduction processing in a wireless communication system.
- a base station forms a cell
- a user apparatus UE is located in the cell and performs communication.
- a base station 1 (referred to as a connection base station 1) and a base station 2 (referred to as an interference base station 2) are adjacent to each other, and a user device 10 (referred to as a connected user device 10).
- the user apparatus UE11 (referred to as the interfering user apparatus 11) is located in the cell (interfering cell) of the interfering base station 2, and the interfering user apparatus 11 is connected to the connected cell and the interfering cell.
- the uplink signal received by the connecting base station 1 from the interference user apparatus 11 is an uplink interference signal in the connecting base station 1.
- Such an interference signal leads to a decrease in user throughput in the uplink.
- Interference suppression combining is a technique for estimating a channel of an interference signal and giving a weight (MMSE standard reception weight) to a signal obtained from each reception antenna.
- IRC includes Type 2 for estimating correlation information of interference signals from pilots of desired signals.
- Type 1 has higher interference suppression capability, but type 1 requires channel estimation of interference signals.
- SIC successive interference cancellation
- Sequential interference cancellation is a technique for extracting a desired signal by creating a replica signal by hard decision or soft decision of an interference signal from a received signal and sequentially subtracting (removing) the replica signal from the received signal.
- the SIC performs channel estimation of the interference signal for each of the plurality of interference signals, demodulates the interference signal based on the channel estimation, creates a replica of the interference signal, and sequentially subtracts from the received signal.
- ML maximum likelihood estimation
- a maximum likelihood determination detector MLD: Maximum Likelihood Detector
- the MLD calculates the likelihood of all signal point combinations of the desired signal and the interference signal, and sets the pair of signal points with the highest likelihood as the signal transmitted from each base station.
- interference signals can also be suppressed by using the maximum likelihood estimation technique.
- the present invention has been made in view of the above points, and provides a technique that enables a base station in a wireless communication system to appropriately perform interference reduction processing on an interference signal transmitted from a user apparatus of an interference cell.
- the purpose is to do.
- an uplink interference reduction method executed in a radio communication system including a connection base station and an interference base station to which an interference user apparatus that transmits an interference signal for the connection base station is connected. Because A control information transmission step in which the interference base station transmits control information used to reduce the interference signal in the connection base station to the connection base station; An uplink interference reduction method comprising: an interference reduction step in which the connected base station reduces the interference signal using the control information and acquires a desired signal transmitted from a user apparatus connected to the connected base station. Is provided.
- connection base station in a wireless communication system including a connection base station and an interference base station to which an interference user apparatus that transmits an interference signal for the connection base station is connected.
- a base station A control information receiving unit that receives control information used to reduce interference signals in the connecting base station from the interference base station;
- a base station is provided that includes an interference reduction processing unit that reduces the interference signal using the control information and acquires a desired signal transmitted from a user apparatus connected to the connected base station.
- a base station in a wireless communication system can appropriately perform interference reduction processing on an interference signal transmitted from a user apparatus of an interference cell.
- FIG. It is a figure for demonstrating TTI bundling. It is a figure for demonstrating phase rotation amount (alpha). It is a figure which shows the information contained in the DCI format 0.
- FIG. It is an operation example when downlink data (PDSCH) is transmitted simultaneously with UL scheduling grant (DCI format 0). It is an operation example when PUSCH and periodic CSI feedback occur simultaneously. It is an operation example when scheduling PUSCH and aperiodic CSI feedback. It is a figure which shows the information required for the interference cancellation of an uplink.
- PDSCH downlink data
- DCI format 0 UL scheduling grant
- PUSCH and periodic CSI feedback occur simultaneously.
- scheduling PUSCH and aperiodic CSI feedback It is a figure which shows the information required for the interference cancellation of an uplink.
- SIC is described as an example of interference reduction processing, but the present invention is not limited to SIC but can be applied to IRC (type 1) and MLD.
- control information related to the Rel-8 PUSCH is described as uplink control information, but this is merely an example for explanation, and the present invention basically includes LTE. Applicable to any Rel and any UL channel.
- FIG. 2 shows a schematic configuration diagram of a radio communication system according to the embodiment of the present invention.
- the radio communication system according to the present embodiment is an LTE (not limited to a specific Rel) radio communication system, in which base station 100 (connected base station) forms a connected cell, and user equipment 300 (connected) in the cell. User apparatus) communicates with the connected base station 100 using a desired signal.
- LTE not limited to a specific Rel
- the adjacent interference base station 200 also forms a cell, and performs signal transmission / reception with the interference user apparatus 400 using the interference base station 200 as a connection base station.
- the uplink signal transmitted from the interference user apparatus 400 located in the cell of the adjacent interference base station 400 becomes an uplink interference signal for the connecting base station 100.
- base stations between connecting base station 100 and interfering base station 200 are connected via an X2 interface, and communication between base stations is possible.
- Control information (interference control information) necessary for performing interference signal reduction processing in the connecting base station 100 is transmitted to the station 100, and the connecting base station 100 uses the control information to reduce interference with the interference signal. Execute the process.
- “Reducing the interference signal” is a general term for expressions such as canceling the interference signal and suppressing the interference signal.
- the method is not limited to a specific method. That is, the method for canceling the interference signal and the method for suppressing the interference signal are not limited to specific methods, respectively.
- any method of SIC, MLD, and IRC type 1 may be used as interference reduction processing, but in this embodiment, it is assumed that symbol-level SIC is used.
- the uplink signal that is subject to interference reduction processing is not limited to a specific signal, but in this embodiment, it is assumed that the uplink signal that is subject to interference reduction processing is a signal transmitted by PUSCH. ing. A signal transmitted on the PUSCH may be referred to as “data”.
- the term “PUSCH” may be used to mean a signal / data transmitted on the PUSCH.
- FIG. 3 shows a configuration example of an SIC receiver that is provided in the connecting base station 100 and performs uplink interference reduction processing. Since the SIC receiver itself is an existing technology, the configuration will be briefly described. As shown in FIG. 3, the SIC receiver in this example includes a CP detector 21, 31, FFT 22, 32, a channel estimator 41, an interference canceller 42, a first stage 50 that performs interference signal detection, and a desired signal detection. A second stage 60 is included.
- the first stage 50 includes a signal detection unit (IRC2) 51, an IDFT 52, a soft decision symbol estimation unit 53, and a DFT 54.
- the second stage 60 includes a signal detection unit (IRC2) 61, an IDFT 62, an LLR calculation unit 63, a channel deinterleaver 64, and a turbo decoder 65.
- the channel estimation unit 41 performs channel estimation of the interference signal and the desired signal, and uses the channel estimation result to demodulate the interference signal (PUSCH in the present embodiment) in the first stage 50.
- the interference canceller 42 subtracts the interference signal from the received signal, whereby a highly accurate desired signal is acquired in the second stage.
- the first stage 50 performs the decoding up to the interference signal.
- control information for channel estimation of the interference signal (PUSCH) and control information for demodulation of the interference signal (PUSCH) are stored in the connecting base station 100. Necessary.
- control information necessary for interference reduction will be described. However, in the description, first, an outline of an LTE uplink channel (particularly PUSCH) that is a target of interference reduction in this embodiment will be described. Then, control information necessary for reducing interference will be described. Control information necessary for interference reduction may be referred to as interference reduction information.
- LTE uplink (LTE uplink)
- PUSCH a target of interference reduction processing
- PUCCH is a control channel for transmitting CQI (Channel Quality Indicator), SR (Scheduling request), ACK / NACK, and the like.
- PUSCH is a data channel used for transmission of traffic data and transfer of control data for higher layers.
- PRACH is a channel used for transmission of RACH preamble.
- DMRS Demodulation Reference Signal
- SRS Sounding Reference Signal
- UL Physical signals UL Physical signals
- DMRS is a signal used for PUSCH and PUCCH channel estimation.
- SRS is a signal used for uplink channel quality measurement, eNB-UE timing measurement, UL scheduling, and the like.
- PUCCH is arranged in RB (Resource Block) at both ends of the system band.
- SRS is arranged in the last symbol of the subframe, and PRACH is arranged in 6 RBs of the subframe determined for each cell.
- PUSCH is allocated to resources other than the above.
- FIG. 4 shows an arrangement example in the radio resources of PUSCH, SRS, and PUCCH.
- PUSCH (allocation resource) of each user is multiplexed by frequency and time.
- frequency is orthogonalized between users, there is no interference within the same cell, and frequency resources with high reception quality can be allocated by frequency scheduling.
- DMRS is multiplexed on PUSCH.
- the DMRS multiplexed on the RB that transmits the PUSCH is used for channel estimation for demodulating the PUSCH.
- DMRS is multiplexed on the third SC-FDMA symbol of each slot, and cyclic shift multiplexing is applied.
- the Zadoff-Chu sequence is a type of CAZAC (Constant Amplitude Zero Auto-Correlation) sequence, and has the characteristics that the amplitude of the sequence is constant and the autocorrelation value other than zero shift is zero. It also has excellent cross-correlation characteristics.
- the number of sequence patterns of the Zadoff-Chu sequence is maximum when the sequence length N is a prime number, and (N ⁇ 1) sequences can be generated.
- N the sequence length of the number of assigned RBs ⁇ 12 subcarriers is required. Therefore, in order to maximize the number of pattern patterns, Zadoff ⁇ is the maximum prime number not exceeding RB ⁇ 12.
- a Chu sequence is generated, and the shortage is compensated by cyclic extension.
- DM-RS In DM-RS, 30 sequence groups and two types of base sequence indexes (when RB> 6) are used. However, if the same sequence group / base sequence index is applied between cells, the signal collides and the characteristics deteriorate, so the probability of collision is reduced by hopping.
- hopping two types of hopping are defined: group hopping and sequence hopping.
- Group hopping is to hop sequence group numbers in slot units based on Cell-ID.
- hopping is performed as shown on the left side of FIG. 6B. If not, a signal collision occurs.
- the probability of collision can be reduced by hopping the sequence group number used when generating the DMRS sequence on a slot basis.
- Group hopping and sequence hopping cannot be used together. Whether or not hopping is applied and the hopping method are notified through the broadcast channel.
- FIG. 7 is a diagram showing a detailed example of group hopping.
- cells with Cell-IDs # 0 to # 89 are shown.
- Cell-ID # 0 to # 29 patterns are generated from one random sequence
- Cell-ID # 30 to # 59 patterns are generated from one random sequence
- Cell-ID # 60 to # 29 89 patterns are generated from one random sequence.
- the group number in each slot in each pattern is cyclically shifted. For example, Cell-ID # 0 and Cell ID # 1 in FIG. 7 are shifted by one.
- ⁇ About PUSCH> A signal transmission / reception procedure regarding PUSCH will be described with reference to FIG. Below, a base station is set to eNB and a user apparatus is demonstrated to UE.
- the eNB transmits a PDCCH to the UE (step 10).
- FIG. 8 also shows a propagation delay (Tp: Propagation delay).
- the eNB determines whether or not to perform retransmission according to the PUSCH decoding result (CRC OK / NG) received in the subframe (# n + 4), and at the time of retransmission, PHICH (NACK) or PDCCH (UL scheduling grant) is transmitted to the UE (step 13), and retransmission is instructed to the UE.
- CRC OK / NG PUSCH decoding result
- PHICH NACK
- PDCCH UL scheduling grant
- UCI When the transmission timing of UCI (CQI, RI, ACK / NACK) by PUCCH and the transmission timing of PUSCH are the same, UCI is multiplexed on PUSCH and transmitted. This is to ensure the characteristics of the single carrier.
- UCI is arranged as shown in FIG. 9 when viewed before DFT. That is, ACK / NACK is arranged in a symbol adjacent to DMRS, RI is arranged in a symbol adjacent to the arrangement position of ACK / NACK, and CQI is arranged over all symbols.
- frequency hopping is applied to obtain frequency diversity in PUSCH.
- Frequency hopping includes Intra-TTI hopping that performs hopping in slot units within TTI and Inter-TTI hopping that performs hopping between TTIs.
- FIG. 10A shows an example of Intra-TTI hopping
- FIG. 10B shows an example of Inter-TTI hopping. As shown in FIG. 10B, Inter-TTI hopping is performed to change the RB used at the time of retransmission.
- TTI bundling may be performed in which one piece of information (PUSCH data or the like) is transmitted across a plurality of TTIs. This improves the coverage, and is particularly effective for GBR (Guaranteed Bit Rate) services such as VoIP.
- GBR Guard Bit Rate
- control information for performing interference reduction processing As already described, information for channel estimation of interference signals and information for PUSCH demodulation (demodulation and decoding in the case of codeword SIC) are required as control information for performing interference reduction processing. . Each will be described below.
- DMRS sequence information that is a PUSCH demodulation reference signal is required.
- A base Zadoff-Chu sequence
- B phase rotation amount
- Zadoff-Chu sequence also referred to as a base sequence
- information on the allocated bandwidth of PUSCH is necessary. This is because the sequence changes according to the allocated bandwidth (number of RBs) of PUSCH.
- Zadoff-Chu sequence information on which Zadoff-Chu sequence is used is necessary. Specifically, a group number (group number, all 30 patterns) and a base sequence number (base sequence number, 1 pattern if allocation is up to 5 RBs, 2 patterns if more) are required.
- the group number / base sequence number itself may be notified, or the hopping information and the slot number may be notified.
- the hopping information includes group hopping information and sequence hopping information.
- the group hopping information includes information indicating whether or not to perform group hopping (eg, “Group-hopping-enabled” notified by high layer), and a physical cell ID as information for generating a hopping pattern, And Sequence-shift pattern.
- the Sequence-shift pattern can be calculated from the PCS and ⁇ ss notified by the high layer.
- Information related to sequence hopping includes information on whether or not to perform sequence hopping (eg, “Sequence-hopping-enabled” notified by high layer), and PCID and Sequence-- as information for generating a hopping pattern. shift pattern, etc. If the allocation is up to 5 RBs, there is only one pattern and hopping is not performed.
- phase rotation amount for base sequence ⁇ As shown in FIG. 12, the DM-RS base sequence is phase-shifted by a predetermined phase rotation amount ( ⁇ ), and then subjected to OFDM modulation and transmitted. This phase rotation amount ( ⁇ ) is required to identify DMRS sequence information.
- ⁇ itself may be notified from the interfering base station 200 to the connecting base station 100, or information necessary for calculating ⁇ may be notified, and the connecting base station 100 may calculate ⁇ .
- Information necessary to calculate ⁇ includes, for example, “cyclic Shift” information notified by Higher layer, cyclic shift for DMRS (described later) notified by downlink DCI format 0, PCID, slot number n s , and Sequence-shift pattern (f ss ) or the like.
- Information necessary for PUSCH demodulation is allocated band information, PUSCH hopping information, modulation information, information indicating whether SRS is configured, and information indicating whether UCI is multiplexed. These are information necessary for the demodulation of PUSCH assuming a symbol level SIC. In the case of a codeword SIC, as information for decoding, in addition to these, encoded information, redundant version, scrambling Information, C-RNTI (or parity check bit) is required. These pieces of information are notified from the interference base station 200 to the connecting base station 100 as interference control information.
- TTI bundling information and information indicating whether to perform PUSCH hopping at the time of retransmission may be notified. By notifying them, it is possible to improve the interference detection capability.
- allocated band information PUSCH hopping information, modulation information, encoded information / redundant version are information included in, for example, DCI format 0 (control information notified by PDCCH).
- FIG. 13 shows an example of DCI format 0 (refer to Non-Patent Document 3 for details).
- the rightmost column in FIG. 13 shows whether or not the corresponding information is necessary for the SIC.
- Information that is displayed as “necessary” in FIG. 13 may be notified from the interfering base station 200 to the connecting base station 100.
- CQI request is information indicating whether or not to perform aperiodic CQI transmission, and is information necessary for UCI multiplexing determination as will be described later.
- the connected base station 100 can determine whether the UCI of the subordinate UE is multiplexed with the PUSCH because it is an item configured to the UE by itself. However, since the interference UE signal cannot be grasped, in the present embodiment, the interference base station 200 notifies the connected base station 100 of information indicating this to the explicit. More specifically, the information includes information indicating whether or not UCI multiplexing is performed (or information indicating that UCI multiplexing is performed) and information indicating which UCI format is multiplexed. It is. However, the latter UCI format information is not necessary if the PUSCH of the interference UE is QPSK and the interference reduction processing is a symbol level SIC.
- FIGS. 14 to 16 Three examples are shown in FIGS. 14 to 16 as examples when UCI multiplexing is performed.
- a base station is assumed to be eNB and a user apparatus is assumed to be UE.
- FIG. 14 shows an example in which downlink data (PDSCH) is transmitted simultaneously with UL scheduling grant (DCI format 0).
- PDSCH downlink data
- DCI format 0 UL scheduling grant
- step 32 when PDSCH and PDCCH (UL scheduling grant) are simultaneously transmitted from the eNB to the UE (step 31), in step 32, ACK / NACK is multiplexed from the UE to the eNB. PUSCH is transmitted.
- FIG. 15 is an example when PUSCH and periodic CSI feedback occur simultaneously.
- the PUSCH transmission timing from the UE coincides with the periodic CSI feedback timing, and the PUSCH and the periodic CSI are simultaneously transmitted from the UE to the eNB.
- FIG. 16 shows an example in which PUSCH and aperiodic CSI feedback are scheduled.
- step 51 when PUSCH is scheduled by UL scheduling grant from eNB to UE and non-periodic CSI feedback is scheduled (step 51), in step 52, non-periodic CSI feedback is sent from UE to eNB.
- PUSCH multiplexed with periodic CSI (CQI in FIG. 16) is transmitted.
- FIG. 17 is a diagram summarizing examples of interference control information that is information necessary for interference reduction processing (here, SIC) of interference signals in the connecting base station 100.
- SIC interference reduction processing
- information that can change dynamically (eg, subframe or slot unit) among information for channel estimation includes PCID, allocated bandwidth, Zadoff-Chu sequence information, phase rotation There is information ( ⁇ ) and the like, and semi-static or static information includes Zadoff-Chu hopping information.
- information that can change dynamically includes allocated band information, PUSCH hopping information, modulation scheme, coding information, redundant version, scrambling information, UCI multiplexing information, etc.
- C-RNTI C-RNTI
- SRS configuration etc. as semi-static or static information.
- TTI bundling information includes TTI bundling information and Inter TTI hopping information.
- the “semi-static” information is information notified by RRC signaling, for example. Also, “information is transmitted semi-statically” means that information is transmitted at a time interval longer than that of dynamic (eg, subframe unit).
- the information shown in FIG. 17 is an example, and all of the information may be transmitted from the interfering base station 200 to the connecting base station 100, or a part of the information may be transmitted. Further, information not described in FIG. 17 may be transmitted from the interference base station 200 to the connecting base station 100. In the case of transmitting some information, the necessary information not to be transmitted may be estimated if it can be estimated by the connecting base station 100. If estimation is difficult, for example, a predetermined value is used. It is good to do.
- dynamically changing information is basically transmitted dynamically, but dynamically changing information may be transmitted semi-statically or statically.
- interference control information is notified (signaled) from the interference base station 200 to the connecting base station 100 through, for example, the X2 interface in the patterns shown in the following method 1 to method 4.
- the use of the X2 interface is an example, and the interference control information may be transmitted / received by any route as long as necessary information can be transmitted / received between the base stations.
- Method 2 a part of the interference control information to be notified from the interference base station 200 to the connection base station 100 (eg, information that changes semi-statically) is reported semi-statically, and the remaining information is transmitted. Notify dynamically. This will be referred to as method 2-1. Further, the remaining information may be estimated on the connected base station 100 side. A method for estimating the remaining information in this way is referred to as method 2-2.
- Method 3 a set of some interference control information (eg, information that changes semi-statically) in a plurality of interfering user apparatuses is semi-statically notified from the interfering base station 200 to the connecting base station 100. Information indicating which interference user apparatus is assigned the PUSCH is dynamically notified. The remaining information may be notified dynamically (this is referred to as method 3-1) or may be estimated on the connected base station 100 side (this is referred to as method 3-2).
- some interference control information eg, information that changes semi-statically
- Information indicating which interference user apparatus is assigned the PUSCH is dynamically notified.
- the remaining information may be notified dynamically (this is referred to as method 3-1) or may be estimated on the connected base station 100 side (this is referred to as method 3-2).
- Method 4 it is assumed that there are a plurality of interfering base stations, and the plurality of interfering base stations transmits part of the interference control information (for example, information that changes semi-statically) to each of the connecting base stations 100 semi-statically.
- Each interfering base station dynamically transmits information (ON / OFF information) indicating whether or not the own cell actually causes uplink interference to the connecting base station 100.
- the remaining information may be notified dynamically (this is referred to as method 4-1) or may be estimated on the connected base station 100 side (this is referred to as method 4-2).
- FIG. 18 is a block diagram showing a schematic configuration of the base station according to the embodiment of the present invention.
- FIG. 18 corresponds to the system configuration shown in FIG. 2, and shows a connection base station 100, an interference base station 200, a connection user device 300, and an interference user device 400. Further, FIG. 18 illustrates functions related to the uplink interference signal reduction processing in each base station.
- the connecting base station 100 receives from the interfering base station 200 a control information receiving unit 121 that receives control information used to reduce an interference signal for the connecting base station 100, and the control information
- the interference reduction processing unit 122 that reduces the interference signal and acquires a desired signal transmitted from the connected user apparatus 300 is provided.
- the interference base station 200 includes a control information generation unit 231 that generates control information (information related to an uplink desired signal of the interference user apparatus 400), and a control information transmission unit 232 that transmits the control information to the connection base station 100. .
- FIG. 19 is a block diagram showing a detailed configuration of each device according to the embodiment of the present invention.
- FIG. 19 corresponds to the system configuration shown in FIG. 2, and shows a connection base station 100, an interference base station 200, a connection user device 300, and an interference user device 400.
- the connecting base station 100 includes a scheduling information determining unit 101, a control information sharing unit 102, a wired I / F 103, a transmission data receiving unit 104, an interference control information estimating unit 105, an interference control information accumulating unit 106, An SIC unit 107, a reception data storage unit 108, and a wireless I / F 109 are included.
- the interference base station 200 has a similar configuration. Below, each function part of the connection base station 100 is demonstrated, but each function part in the interference base station 200 is also the same.
- the scheduling information determination unit 101 determines (generates) resource allocation information (control information) of subordinate user devices.
- the control information sharing unit 102 notifies the control information (interference control information for other base stations) determined by the scheduling information determining unit 101 to other base stations.
- the wired I / F 103 is a wired I / F between base stations, but this may be a wireless I / F.
- the transmission data receiving unit 104 receives data transmitted from the user device.
- the interference control information estimation unit 105 estimates interference signal control information from the received signal. In addition, when not estimating, the interference control information estimation part 105 does not need to be provided.
- the estimation method is not limited to a specific method, and an arbitrary method can be used. As an example, when the possible values of information to be estimated are limited, the most probable value may be estimated from the received signal, or the value obtained by decoding the control signal of the interference signal is estimated. It can also be used as a value.
- the interference control information accumulation unit 106 receives and accumulates interference signal control information (interference control information) from other base stations.
- the SIC unit 107 performs SIC on the interference signal using the control information of the reception signal and the interference signal, and decodes the reception data.
- the reception data storage unit 108 is a memory that stores reception data, and the wireless I / F 109 performs wireless communication with the user device.
- the connected user apparatus 300 includes a scheduling request unit 301, a transmission control information receiving unit 302, a transmission data storage unit 303, a transmission signal generation unit 304, and a wireless I / F 305.
- the interference user apparatus 400 also has the same configuration. Hereinafter, each function unit of the connected user apparatus 300 will be described, but each function unit in the interference user apparatus 400 is the same.
- the scheduling request unit 301 requests uplink resource allocation to the base station.
- the transmission control information receiving unit 302 receives resource allocation information from the base station.
- the transmission data storage unit 303 is a memory that stores data to be transmitted.
- the transmission signal generation unit 304 modulates and encodes transmission data into a radio signal based on the control information received from the base station.
- the wireless I / F 305 performs wireless communication with the base station.
- each device shown in FIG. 18 and FIG. 19 may be realized entirely by a hardware circuit (eg, one or a plurality of IC chips), or part of the configuration may be realized by a hardware circuit.
- the portion may be realized by a CPU and a program.
- FIG. 20 is a diagram illustrating an example of a hardware (HW) configuration of a user apparatus UE corresponding to the connected user apparatus 300.
- FIG. 20 shows a configuration closer to the mounting example than the configurations shown in FIGS. 18 and 19.
- the UE includes an RE (Radio Equipment) module 551 that performs processing related to a radio signal, a BB (Base Band) processing module 552 that performs baseband signal processing, and a device that performs processing such as an upper layer. It has a control module 553 and a USIM slot 554 which is an interface for accessing the USIM card.
- RE Radio Equipment
- BB Base Band
- USIM slot 554 which is an interface for accessing the USIM card.
- the RE module 551 should transmit the digital baseband signal received from the BB processing module 552 from the antenna by performing D / A (Digital-to-Analog) conversion, modulation, frequency conversion, power amplification, and the like. Generate a radio signal.
- a digital baseband signal is generated by performing frequency conversion, A / D (Analog to Digital) conversion, demodulation, and the like on the received radio signal, and the digital baseband signal is passed to the BB processing module 552.
- the functions of each part of the connected user apparatus 300 shown in FIG. 18 or 19 may be included in the RE module 551, or some functions of the connected user apparatus 300 shown in FIG. 18 or FIG. 551 and other functions may be included in the following BB processing module 552.
- the BB processing module 552 performs processing for mutually converting an IP packet and a digital baseband signal.
- a DSP (Digital Signal Processor) 562 is a processor that performs signal processing in the BB processing module 552.
- the memory 572 is used as a work area for the DSP 562.
- the device control module 553 performs IP layer protocol processing, various application processing, and the like.
- the processor 563 is a processor that performs processing performed by the device control module 553.
- the memory 573 is used as a work area for the processor 563.
- the processor 563 reads and writes data with the USIM through the USIM slot 554.
- FIG. 21 is a diagram illustrating an example of a hardware (HW) configuration of a base station eNB corresponding to the connected base station 100.
- FIG. 21 shows a configuration closer to the mounting example than the configurations shown in FIGS. 18 and 19.
- the base station eNB includes an RE module 651 that performs processing related to a radio signal, a BB processing module 652 that performs baseband signal processing, a device control module 653 that performs processing such as an upper layer, a network, And a communication IF 654 which is an interface for connection.
- RE module 651 that performs processing related to a radio signal
- BB processing module 652 that performs baseband signal processing
- a device control module 653 that performs processing such as an upper layer, a network
- a communication IF 654 which is an interface for connection.
- the RE module 651 generates a radio signal to be transmitted from the antenna by performing D / A conversion, modulation, frequency conversion, power amplification, and the like on the digital baseband signal received from the BB processing module 652.
- a digital baseband signal is generated by performing frequency conversion, A / D conversion, demodulation, and the like on the received radio signal, and is passed to the BB processing module 652.
- the functions of the respective units of the connected base station 100 shown in FIG. 18 or 19 may be included in the RE module 651, or some functions of the connected base station 100 shown in FIG. 18 or FIG. 651 and other functions may be included in the following BB processing module 652.
- the BB processing module 652 performs processing for mutually converting an IP packet and a digital baseband signal.
- the DSP 662 is a processor that performs signal processing in the BB processing module 652.
- the memory 672 is used as a work area for the DSP 652.
- the device control module 653 performs IP layer protocol processing, OAM processing, and the like.
- the processor 663 is a processor that performs processing performed by the device control module 653.
- the memory 673 is used as a work area for the processor 663.
- the auxiliary storage device 683 is, for example, an HDD or the like, and stores various setting information for operating the base station eNB itself.
- FIG. 22 is a sequence diagram in the case of dynamically reporting all information for each subframe, corresponding to method 1.
- the connected base station 100 determines scheduling (eg, PUSCH allocation) of the connected user apparatus 300, and controls information (eg, UL). grant) is transmitted to the connected user apparatus 300 (step 103). Thereby, the connected user apparatus 300 generates a transmission signal (step 104), and transmits a desired signal (data transmitted by PUSCH, etc.) to the connected base station 100 (step 105).
- scheduling e.g, PUSCH allocation
- controls information eg, UL). grant
- the interference base station 200 when the interference user apparatus 400 transmits a scheduling request to the interference base station 200 (step 201), the interference base station 200 performs scheduling of the interference user apparatus 400 (example: PUSCH allocation).
- the control information (eg, UL grant) is transmitted to the interference user apparatus 400 (step 203).
- the interference user apparatus 400 generates a transmission signal (step 205), and transmits the interference signal (desired signal for the interference base station 200) to the interference base station 200 (step 206).
- the interference signal arrives at the connecting base station 100.
- the interference base station 200 notifies the connection base station 100 of interference control information (step 204).
- the connecting base station 100 performs SIC reception processing using the interference control information (step 106), and decodes transmission data (step 107). That is, the connecting base station 100 demodulates the interference signal among the reception signals received in Step 105 and Step 206, acquires the desired signal by canceling the interference signal from the reception signal, and decodes the desired signal. Go and get the transmission data.
- FIG. 23 is a sequence diagram corresponding to the method 2-1, in which a part of information is notified semi-statically and the remaining information is notified dynamically.
- the interference base station 200 transmits a part of interference control information semi-statically to the connecting base station 100 (step 211).
- the connected base station 100 determines scheduling (eg, PUSCH allocation) of the connected user apparatus 300, and controls information (example) : UL grant) is transmitted to the connected user apparatus 300 (step 103). Thereby, the connected user apparatus 300 generates a transmission signal (step 104), and transmits a desired signal (data transmitted by PUSCH, etc.) to the connected base station 100 (step 105).
- scheduling eg, PUSCH allocation
- UL grant UL grant
- the interference base station 200 when the interference user apparatus 400 transmits a scheduling request to the interference base station 200 (step 201), the interference base station 200 performs scheduling of the interference user apparatus 400 (example: PUSCH allocation).
- the control information (eg, UL grant) is transmitted to the interference user apparatus 400 (step 203).
- the interference user apparatus 400 generates a transmission signal (step 205), and transmits the interference signal (desired signal for the interference base station 200) to the interference base station 200 (step 206).
- the interference signal arrives at the connecting base station 100.
- the interference base station 200 notifies the remaining base station 100 of the remaining interference control information (dynamic information) (step 204).
- the connecting base station 100 performs SIC reception processing using the interference control information received in step 211 and the interference control information received in step 204 (step 106), and decodes transmission data (step 107).
- FIG. 24 is a sequence diagram corresponding to method 2-2, in which a part of information is notified semi-statically and the remaining information is estimated on the base station side.
- FIG. 24 differs from FIG. 23 in that step 204 in FIG. 23 is not present and step 111 is added, and the other processes are the same.
- the connecting base station 100 estimates interference control information not received in step 211 based on the interference signal received in step 206, for example.
- the connecting base station 100 performs SIC reception processing using the interference control information received in step 211 and the interference control information estimated in step 111 (step 106), and decodes transmission data (step 107).
- FIG. 25 is a sequence diagram corresponding to methods 3-1 and 3-2, in which a set of interference control information of a plurality of UEs is notified semi-statically, and actual allocation UE information is dynamically notified.
- the interference base station 200 semi-statically transmits some interference control information to the connecting base station 100 (step 221).
- the interference control information transmitted here is interference control information regarding a plurality of interference user apparatuses.
- the connected base station 100 determines scheduling (eg, PUSCH allocation) of the connected user apparatus 300, and controls information (eg, UL). grant) is transmitted to the connected user apparatus 300 (step 103). Thereby, the connected user apparatus 300 generates a transmission signal (step 104), and transmits a desired signal (data transmitted by PUSCH, etc.) to the connected base station 100 (step 105).
- scheduling e.g, PUSCH allocation
- controls information eg, UL). grant
- the interference base station 200 when the interference user apparatus 400 transmits a scheduling request to the interference base station 200 (step 201), the interference base station 200 performs scheduling of the interference user apparatus 400 (example: PUSCH allocation).
- the control information (eg, UL grant) is transmitted to the interference user apparatus 400 (step 203).
- the interference user apparatus 400 generates a transmission signal (step 205), and transmits the interference signal (desired signal for the interference base station 200) to the interference base station 200 (step 206).
- the interference signal arrives at the connecting base station 100.
- the interference base station 200 After determining the scheduling, the interference base station 200 provides information on the interference user apparatus that has performed the allocation (eg, C-RNTI, which is unique information of each UE, and information indicating to which UE the PUSCH resource is allocated). Transmit to the connecting base station 100 (step 222).
- the interference base station 200 When performing the operation of the method 3-1, the interference base station 200 notifies the connected base station 100 of the remaining interference control information (dynamic information) (step 223).
- the connecting base station 100 estimates the remaining interference control information (dynamic information) (step 121).
- the connecting base station 100 performs SIC reception processing using the interference control information received in step 221, the assigned UE information received in step 222, and the interference control information received in step 223 or estimated in step 121 ( Step 106), the transmitted data is decoded (Step 107).
- FIG. 26 is a sequence diagram in the case of semi-statically reporting a set of interference control information regarding a plurality of interfering base stations and dynamically notifying an actual interference generating base station, corresponding to methods 4-1 and 4-2. .
- a plurality of interference base stations including the interference base station 200 and other interference base stations transmit a part of interference control information semi-statically to the connecting base station 100 (step 231).
- the connected base station 100 determines scheduling (eg, PUSCH allocation) of the connected user apparatus 300, and controls information (eg, UL). grant) is transmitted to the connected user apparatus 300 (step 103). Thereby, the connected user apparatus 300 generates a transmission signal (step 104), and transmits a desired signal (data transmitted by PUSCH, etc.) to the connected base station 100 (step 105).
- scheduling e.g, PUSCH allocation
- controls information eg, UL). grant
- the interference base station 200 when the interference user apparatus 400 transmits a scheduling request to the interference base station 200 (step 201), the interference base station 200 performs scheduling of the interference user apparatus 400 (example: PUSCH allocation).
- the control information (eg, UL grant) is transmitted to the interference user apparatus 400 (step 203).
- the interference user apparatus 400 generates a transmission signal (step 205), and transmits the interference signal (desired signal for the interference base station 200) to the interference base station 200 (step 206).
- the interference signal arrives at the connecting base station 100.
- One or more of the plurality of interfering base stations described above perform such operations.
- Each of the plurality of interference base stations including the interference base station 200 indicates ON / OFF information indicating whether or not an interference signal for the connected base station 100 is generated under its control (for example: It may be explicitly indicated by 1 bit, or may be indicated implicitly by notification of the dynamic information of the interference signal) (step 232). Whether or not an interference signal for the connected base station 100 is generated can be determined from, for example, the contents of uplink scheduling (eg, determination is made that interference occurs when uplink transmission is assigned to a UE near the cell edge).
- the interference base station eg, the interference base station 200
- the connecting base station 100 estimates the remaining interference control information (dynamic information) for the interference base station (for example, the interference base station 200) that transmitted the ON information in Step 232 ( Step 131).
- the connecting base station 100 performs SIC reception processing using the interference control information received in step 231, the ON / OFF information received in step 232, and the interference control information received in step 233 or estimated in step 131. (Step 106), the transmission data is decoded (Step 107).
- an uplink executed in a radio communication system including a connection base station and an interference base station to which an interference user apparatus that transmits an interference signal for the connection base station is connected.
- An interference reduction method wherein the interference base station transmits control information used to reduce the interference signal in the connection base station to the connection base station, and the connection base station
- An uplink interference reduction method comprising: an interference reduction step of reducing the interference signal using the control information and acquiring a desired signal transmitted from a user apparatus connected to the connection base station.
- the base station in the wireless communication system can appropriately perform the interference reduction process on the interference signal transmitted from the user apparatus of the interference cell.
- the interference base station transmits part of the control information semi-statically to the connection base station and dynamically transmits the remaining control information to the connection base station. With this configuration, it is possible to reduce information to be notified dynamically and to reduce the processing load.
- the interference base station transmits a part of the control information semistatically to the connection base station, and in the interference reduction step, the connection base station estimates the remaining control information,
- the interference signal may be reduced using the partial control information and the remaining control information.
- the interference base station transmits a set of control information related to a plurality of interfering user apparatuses to the connected base station, and then, among the plurality of interfering user apparatuses, actually performs uplink transmission. It is good also as transmitting the information of the interference user apparatus by which resource allocation was performed to the said connection base station. In this configuration, since the control information is transmitted in advance, the information to be transmitted dynamically can be reduced.
- each of a plurality of interference base stations including the interference base station and other interference base stations transmits control information to the connection base station, and thereafter, the plurality of interference base stations, Information indicating whether or not uplink interference with the connected base station occurs may be transmitted to the connected base station. Also in this configuration, since the control information is transmitted in advance, the information to be dynamically transmitted can be reduced.
- control information includes sequence information of a demodulation reference signal as information used for channel estimation of the interference signal.
- sequence information of a demodulation reference signal as information used for channel estimation of the interference signal.
- the control information may further include information necessary for demodulation of the interference signal. Thereby, successive interference cancellation can be executed appropriately.
- the interference signal is a signal transmitted on the PUSCH
- whether or not UCI is multiplexed on the PUSCH in the control information transmitted from the interference base station to the connecting base station in the control information transmission step. May be included. With this configuration, it is possible to implement interference cancellation with high accuracy in consideration of UCI multiplexing.
- Each base station described in the present embodiment may include a CPU and a memory, and may be realized by a program being executed by a CPU (processor).
- the processing described in the present embodiment The configuration may be realized by hardware such as a hardware circuit provided with logic, or may be a configuration in which a program and hardware are mixed.
- each user device described in the present embodiment may include a CPU and a memory, and may be configured by a program being executed by a CPU (processor), or will be described in the present embodiment.
- the configuration may be realized by hardware such as a hardware circuit including processing logic, or may be a configuration in which a program and hardware are mixed.
- the operations of a plurality of functional units may be physically performed by one component, or the operations of one functional unit may be physically performed by a plurality of components.
- the user apparatus and the base station have been described using functional block diagrams, but such an apparatus may be realized in hardware, software, or a combination thereof.
- Software operated by the processor of the user equipment and software operated by the processor of the base station are random access memory (RAM), flash memory, read only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, respectively. , CD-ROM, database, server or any other suitable storage medium.
- Interference canceller 50 First stage: Interference signal detection 51, 61 Signal detection unit (IRC2) 52, 62 IDFT 53 Soft decision symbol estimator 60 Second stage: Desired signal detection 63 LLR calculator 64 Channel deinterleaver 65 Turbo decoder 121 Control information receiver 122 Interference reduction processor 231 Control information generator 232 Control information transmitter 101, 201 Scheduling information Determination unit 102, 202 Control information sharing unit 103, 203 Wired I / F 104, 204 Transmission data reception unit 105, 205 Interference control information estimation unit 106, 206 Interference control information storage unit 107, 207 SIC unit 108, 208 Reception data storage unit 109, 209 Wireless I / F 301, 401 Scheduling request unit 302, 402 Transmission control information receiving unit 303, 403 Transmission data storage unit 304, 404 Transmission signal generation unit 305, 4
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Abstract
Description
前記干渉基地局が、前記接続基地局において前記干渉信号を低減するために利用される制御情報を前記接続基地局に送信する制御情報送信ステップと、
前記接続基地局が、前記制御情報を利用して前記干渉信号を低減し、前記接続基地局に接続されるユーザ装置から送信される所望信号を取得する干渉低減ステップとを備える上りリンク干渉低減方法が提供される。
前記干渉基地局から、前記接続基地局において干渉信号を低減するために利用される制御情報を受信する制御情報受信部と、
前記制御情報を利用して、前記干渉信号を低減し、前記接続基地局に接続されるユーザ装置から送信される所望信号を取得する干渉低減処理部とを備える基地局が提供される。
図2に、本発明の実施の形態に係る無線通信システムの概要構成図を示す。本実施の形態に係る無線通信システムは、LTE(特定のRelに限定されない)の無線通信システムであり、基地局100(接続基地局)が接続セルを形成し、セル内のユーザ装置300(接続ユーザ装置)が接続基地局100と所望信号による通信を行う。
以下、説明の便宜上、一例としてLTEのRel-8において規定されている上りリンクの内容について説明する。また、特に、本実施の形態において干渉低減処理の対象とするPUSCHに着目して説明する。
LTEでは、UL物理チャネル(UL Physical channels)として、PUCCH(Physical Uplink Control Channel)、PUSCH(Physical Uplink Shared Channel)、PRACH(Physical Random Access Channel)等がある。
図5に示すように、PUSCHにはDMRSが多重される。PUSCHを送信するRBに多重されるDMRSは、PUSCHを復調するためのチャネル推定に用いられる。また、PUSCHにおいて、DMRSは、各スロットの第3SC-FDMAシンボルに多重され、Cyclic shift多重が適用される。
図8を参照してPUSCHに関する信号送受信手順について説明する。以下では、基地局をeNBとし、ユーザ装置をUEとして説明する。
以下、図2に示した本実施の形態に係るシステムにおいて、接続基地局100が干渉信号に対する干渉低減処理を実施するために必要な制御情報の例を説明する。前述したように、本実施の形態では、例として、干渉低減処理の対象となる干渉信号をPUSCHとし、干渉低減処理はSICであるとするが、本発明は他の干渉信号、及び他の干渉低減処理についても適用可能である。
干渉信号のチャネル推定を実施するには、PUSCHの復調用参照信号であるDMRSの系列情報が必要である。DMRSの系列情報を取得するためには、ベースとなるZadoff-Chu系列の特定(A)、及び、当該ベースとなるZadoff-Chu系列に対する位相回転量の特定(B)が必要である。以下、その内容を説明するが、詳細については非特許文献2(Sect. 5.5.1)を参照されたい。
ベースとなるZadoff-Chu系列(ベース系列とも称する)の特定のためには、PUSCHの割り当て帯域幅の情報が必要である。これは、PUSCHの割り当て帯域幅(RB数)に応じて系列が変化するためである。
図12に示すように、DM-RSのベース系列は、所定の位相回転量(α)だけ位相回転がなされた後に、OFDM変調がなされ、送信される。DMRSの系列情報を特定するには、この位相回転量(α)が必要である。
PUSCHの復調のために必要な情報は、割り当て帯域情報、PUSCHホッピング情報、変調情報、SRSがconfigureされているかどうかを示す情報、UCIが多重されているか否かを示す情報、である。これらは、シンボルレベルSICを想定したPUSCHの復調のために必要な情報であり、コードワードSICの場合には、復号のための情報として、これらに加えて、符号化情報・冗長バージョン、スクランブリング情報、C-RNTI(orパリティ検査ビット)が必要となる。これらの情報が、干渉制御情報として干渉基地局200から接続基地局100へ通知される。
上記の情報のうち、割り当て帯域情報、PUSCHホッピング情報、変調情報、符号化情報・冗長バージョンは、例えばDCIフォーマット0(PDCCHで通知される制御情報)に含まれる情報である。
次に、UCIが多重されているか否かを示す情報について説明する。SICにおけるPUSCHの復調において、UCIが多重されている場合には、データのみならずUCIも復調する必要があるから、UCIが多重されていることの情報が必要である。
図17は、接続基地局100において、干渉信号の干渉低減処理(ここではSIC)のために必要となる情報である干渉制御情報の例をまとめた図である。
本実施の形態では、下記の方法1~方法4に示すパターンで干渉制御情報を干渉基地局200から接続基地局100に例えばX2インターフェースにより通知(シグナリング)する。なお、X2インターフェースを使用することは一例であり、基地局間で必要な情報を送受信できるのであればどのようなルートで干渉制御情報を送受信してもよい。
方法1では、干渉基地局200から接続基地局100に対して、通知する全ての干渉制御情報をサブフレーム毎にダイナミックに通知する。
方法2では、干渉基地局200から接続基地局100に対して、通知する干渉制御情報のうちの一部の情報(例:セミスタティックに変化する情報)をセミスタティックに通知し、残りの情報をダイナミックに通知する。これを方法2-1とする。また、残りの情報については、接続基地局100の側で推定することとしてもよい。このように残りの情報を推定する方法を方法2-2とする。
方法3では、干渉基地局200から接続基地局100に対して、複数の干渉ユーザ装置における一部の干渉制御情報(例:セミスタティックに変化する情報)のセットをセミスタティックに通知し、実際にどの干渉ユーザ装置に対してPUSCHが割り当てられているかを示す情報をダイナミックに通知する。残りの情報についてはダイナミックに通知してもよいし(これを方法3-1とする)、接続基地局100側で推定することとしてもよい(これを方法3-2とする)。
方法4では、複数の干渉基地局が存在するものとし、当該複数の干渉基地局が、それぞれにおける一部の干渉制御情報(例:セミスタティックに変化する情報)をセミスタティックに接続基地局100に送信し、各干渉基地局は、自セルが実際に接続基地局100に対して上りリンク干渉を及ぼすか否かを示す情報(ON/OFF情報)をダイナミックに通知する。残りの情報についてはダイナミックに通知してもよいし(これを方法4-1とする)、接続基地局100側で推定することとしてもよい(これを方法4-2とする)。
<概要構成>
次に、本発明の実施の形態におけるシステム構成を説明する。図18は、本発明の実施の形態に係る基地局の概要構成を示すブロック図である。図18は、図2に示すシステム構成に対応しており、接続基地局100、干渉基地局200、接続ユーザ装置300、干渉ユーザ装置400が示されている。また、図18は、各基地局において、特に上り干渉信号の低減処理に関連する機能を示している。
次に、本発明の実施の形態における詳細なシステム構成を説明する。図19は、本発明の実施の形態に係る各装置の詳細構成を示すブロック図である。図19は、図2に示すシステム構成に対応しており、接続基地局100、干渉基地局200、接続ユーザ装置300、干渉ユーザ装置400が示されている。
図18、図19に示した各装置の構成は、全体をハードウェア回路(例:1つ又は複数のICチップ)で実現してもよいし、一部をハードウェア回路で構成し、その他の部分をCPUとプログラムとで実現してもよい。
次に、図22~図26を参照して、図18もしくは図19に示した機能を含むシステムの動作例1~4を説明する。
図22は、方法1に対応し、全ての情報をサブフレーム毎にダイナミックに通知する場合のシーケンス図である。
図23は、方法2-1に対応し、一部の情報をセミスタティックに通知し、残りの情報をダイナミックに通知する場合のシーケンス図である。
図25は、方法3-1、3-2に対応し、複数UEの干渉制御情報のセットをセミスタティックに通知し、実際の割り当てUE情報をダイナミックに通知する場合のシーケンス図である。
図26は、方法4-1、4-2に対応し、複数干渉基地局に関する干渉制御情報のセットをセミスタティックに通知し、実際の干渉発生基地局をダイナミックに通知する場合のシーケンス図である。
2、200 干渉基地局
10、300 接続ユーザ装置
11、400 干渉ユーザ装置
21、31 CP検出部
22、32 FFT
41 チャネル推定部
42 干渉キャンセラ
50 第1ステージ:干渉信号検出
51、61 信号検出部(IRC2)
52、62 IDFT
53 軟判定シンボル推定部
60 第2ステージ:所望信号検出
63 LLR計算部
64 チャネルデインタリーバ
65 ターボデコーダ
121 制御情報受信部
122 干渉低減処理部
231 制御情報生成部
232 制御情報送信部
101、201 スケジューリング情報決定部
102、202 制御情報共有部
103、203 有線I/F
104、204 送信データ受信部
105、205 干渉制御情報推定部
106、206 干渉制御情報蓄積部
107、207 SIC部
108、208 受信データ蓄積部
109、209 無線I/F
301、401 スケジューリング要求部
302、402 送信制御情報受信部
303、403 送信データ蓄積部
304、404 送信信号生成部
305、405 無線I/F
Claims (9)
- 接続基地局と、当該接続基地局に対する干渉信号を送信する干渉ユーザ装置が接続される干渉基地局とを含む無線通信システムにおいて実行される上りリンク干渉低減方法であって、
前記干渉基地局が、前記接続基地局において前記干渉信号を低減するために利用される制御情報を前記接続基地局に送信する制御情報送信ステップと、
前記接続基地局が、前記制御情報を利用して前記干渉信号を低減し、前記接続基地局に接続されるユーザ装置から送信される所望信号を取得する干渉低減ステップと
を備える上りリンク干渉低減方法。 - 前記制御情報送信ステップにおいて、前記干渉基地局は、一部の制御情報をセミスタティックに前記接続基地局に送信し、残りの制御情報をダイナミックに前記接続基地局に送信する
請求項1に記載の上りリンク干渉低減方法。 - 前記制御情報送信ステップにおいて、前記干渉基地局は、一部の制御情報をセミスタティックに前記接続基地局に送信し、
前記干渉低減ステップにおいて、前記接続基地局は、残りの制御情報を推定し、前記一部の制御情報と当該残りの制御情報とを利用して前記干渉信号を低減する
請求項1に記載の上りリンク干渉低減方法。 - 前記制御情報送信ステップにおいて、前記干渉基地局は、複数の干渉ユーザ装置に関する制御情報のセットを前記接続基地局に送信し、その後に、当該複数の干渉ユーザ装置のうち、実際に上りリンク送信のリソース割り当てが行われた干渉ユーザ装置の情報を前記接続基地局に送信する
請求項1ないし3のうちいずれか1項に記載の上りリンク干渉低減方法。 - 前記制御情報送信ステップにおいて、前記干渉基地局及びその他の干渉基地局を含む複数の干渉基地局はそれぞれ、制御情報を前記接続基地局に送信し、その後に、当該複数の干渉基地局はそれぞれ、前記接続基地局に対する上りリンクの干渉が発生するか否かを示す情報を前記接続基地局に送信する
請求項1ないし3のうちいずれか1項に記載の上りリンク干渉低減方法。 - 前記制御情報は、干渉信号のチャネル推定に使用する情報として、復調用参照信号の系列情報を含む
請求項1ないし5のうちいずれか1項に記載の上りリンク干渉低減方法。 - 前記干渉低減ステップにおいて、前記接続基地局が逐次干渉キャンセルを実行する場合に、前記制御情報は更に前記干渉信号の復調のために必要な情報を含む
請求項6に記載の上りリンク干渉低減方法。 - 前記干渉信号が、PUSCHで送信される信号である場合に、前記制御情報送信ステップにおいて前記干渉基地局から前記接続基地局に送信される制御情報には、UCIがPUSCHに多重されているか否かを示す情報が含まれる
請求項1ないし7のうちいずれか1項に記載の上りリンク干渉低減方法。 - 接続基地局と、当該接続基地局に対する干渉信号を送信する干渉ユーザ装置が接続される干渉基地局とを含む無線通信システムにおいて前記接続基地局として使用される基地局であって、
前記干渉基地局から、前記接続基地局において干渉信号を低減するために利用される制御情報を受信する制御情報受信部と、
前記制御情報を利用して、前記干渉信号を低減し、前記接続基地局に接続されるユーザ装置から送信される所望信号を取得する干渉低減処理部と
を備える基地局。
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EP15865274.3A EP3229523A4 (en) | 2014-12-05 | 2015-11-30 | Method for reducing uplink interference, and base station |
US15/532,761 US20170332364A1 (en) | 2014-12-05 | 2015-11-30 | Uplink interference reduction method, and base station |
JP2016562449A JPWO2016088719A1 (ja) | 2014-12-05 | 2015-11-30 | 上りリンク干渉低減方法、及び基地局 |
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Cited By (1)
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US11418227B2 (en) | 2018-10-12 | 2022-08-16 | Nec Corporation | Radio apparatus, signal detection method, non-transitory computer readable medium, and radio communication system |
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KR102316996B1 (ko) * | 2015-04-10 | 2021-10-25 | 삼성전자주식회사 | 간섭 제거 방법 및 그 장치 |
CN108141234B (zh) * | 2015-10-05 | 2022-09-06 | 瑞典爱立信有限公司 | 通信装置、网络节点、方法以及计算机程序 |
EP3471321B1 (en) * | 2017-03-21 | 2021-07-21 | LG Electronics Inc. | Method and apparatuses for transmitting and receiving physical uplink control channel between terminal and base station in wireless communication system |
WO2018204892A1 (en) * | 2017-05-05 | 2018-11-08 | Motorola Mobility Llc | Collision handling between stti and tti transmissions |
RU2741628C1 (ru) * | 2017-08-04 | 2021-01-28 | Гуандун Оппо Мобайл Телекоммьюникейшнз Корп., Лтд. | Способ беспроводной связи и терминальное устройство |
US10448377B2 (en) * | 2017-09-28 | 2019-10-15 | Cavium, Llc | Methods and apparatus for control channel detection in an uplink shared channel |
US10756863B2 (en) | 2018-05-11 | 2020-08-25 | At&T Intellectual Property I, L.P. | Transmitting reference signals in 5G or other next generation communication systems |
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- 2015-11-30 US US15/532,761 patent/US20170332364A1/en not_active Abandoned
- 2015-11-30 EP EP15865274.3A patent/EP3229523A4/en not_active Withdrawn
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US20170332364A1 (en) | 2017-11-16 |
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JPWO2016088719A1 (ja) | 2017-11-02 |
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