JP6424398B2 - Timing synchronization for downlink (DL) transmission in coordinated multipoint (CoMP) systems - Google Patents

Description

Related application

  This application claims the benefit of US Provisional Patent Application No. 61 / 556,109, filed Nov. 4, 2011, having Attorney Docket No. P41399Z, which is incorporated herein by reference.

  Wireless mobile communication techniques use various standards and protocols to transmit data between nodes (eg, transmitting stations) and wireless devices. Some wireless devices communicate through the physical layer using orthogonal frequency-division multiplexing (OFDM) combined with a desired digital modulation scheme. Standards and protocols that use OFDM include the third generation partnership project (3GPP), long term evolution (LTE), WiMAX (Worldwide interoperability for Microwave Access, World Wide Interoperability for 4). Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard (eg, 802.16e, 802.16m), commonly known to industry groups as microwave access), and WiFi Examples include the IEEE 802.11 standard commonly known to industry groups.

  In the 3GPP radio access network (RAN) LTE system, the nodes are designated as Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (generally evolved Node B, It may be a combination of enhanced Node B, eNode B, or eNB) and a Radio Network Controller (RNC), also known as user equipment (UE) Communicate with a wireless device (eg, mobile device). Downlink (DL) transmission may be communication from a node station (or eNodeB) to a wireless device (or UE), and uplink (UL) transmission may be communication from a wireless device to a node.

  In homogeneous networks, nodes, also called macro nodes, can provide basic radio coverage to wireless devices in a cell. A cell may be an area where a wireless device is operable to communicate with a macro node. Heterogeneous networks (HetNet) are used to handle the increased traffic load on macro nodes due to increased utilization and functionality of wireless devices. HetNet may be a lower power node (micro eNB, pico eNB, femto eNB, or home) that may be deployed within the coverage area (cell) of a macro node in a less planned or even totally uncoordinated manner A layer of planned high power macro nodes (or macro eNBs) may be included, on which layers of eNBs [HeNBs (home eNBs)] are superimposed. Lower power nodes (LPNs) can generally be referred to as "low power nodes". Macro nodes can be used for basic coverage, low power nodes improve capacity in hot zones or at the boundaries between coverage areas of macro nodes, and improve indoor coverage where structures interfere with signal transmission Can be used to fill holes in the coverage area. Inter-cell interference coordination (ICIC) or enhanced ICIC (enhanced ICIC, eICIC) is used for resource coordination to reduce interference between nodes such as macro nodes and low power nodes in HetNet. It may be done.

  The features and advantages of the present disclosure will be apparent from the following detailed description in conjunction with the accompanying drawings. The drawings both illustrate features of the present disclosure by way of example.

An example using orthogonal frequency division multiplexing (OFDM) symbol transmission from macro nodes and low power nodes (LPNs) in a cooperating set, and received OFDM symbols at the wireless device and earliest received reference signal (RS) timing FIG. 7 is a schematic representation of the adjustment of a fast Fourier transform (FFT) window. Orthogonal frequency division multiplexed (OFDM) symbol transmission from macro nodes and low power nodes (LPNs) in a coordinated set, and received OFDM symbols at a wireless device, and reference signal received power (RSRP), according to an example. And a schematic of the adjustment of the fast Fourier transform (FFT) window with the received reference signal (RS) timing. Orthogonal frequency division multiplex (OFDM) symbol transmission from multiple cooperating nodes in a cooperating set, and received OFDM symbols at the wireless device, and reference signal received power (RSRP) and received reference signal (RS) timing, according to an example. FIG. 7 is a schematic representation of the adjustment of the fast Fourier transform (FFT) window used. Orthogonal Frequency Division Multiplexing (OFDM) symbol transmission from multiple cooperating nodes in a cooperating set, and received OFDM symbols at the wireless device, and an inverse fast Fourier transform of the first cooperating node using coordinated timing, according to an example. 5 is a schematic representation of the adjustment of the inverse fast Fourier transform (IFFT) window. FIG. 5 is a block diagram of a radio frame resource according to an example. 4 is a flowchart of timing synchronization for downlink (DL) transmission in a Coordinated MultiPoint (CoMP) system according to an example. FIG. 1 is a block diagram of a physical layer of transmitters and receivers in an orthogonal frequency division multiplexing (OFDM) wireless network according to an example. 7 is a flowchart of a method of adjusting receiver timing of a wireless device in a coordinated multipoint (CoMP) system according to an example. 5 is a flowchart of a method of synchronizing downlink (DL) transmission timing of a first cooperating node with respect to downlink transmission of a second cooperating node in a coordinated multipoint (CoMP) system according to an example; FIG. 7 is a block diagram of a wireless device and a plurality of cooperating nodes according to an example. 1 is a schematic diagram of a wireless device according to an example.

  Reference is now made to the exemplary embodiments. Certain terms are used herein to describe these. However, it will be understood that this is not intended to limit the scope of the present invention.

  Before the present invention is disclosed and described, the present invention is not limited to the specific structures, process steps, or materials disclosed herein, but will be recognized by those skilled in the art As such, it should be understood that it extends to its equivalents. It is also to be understood that the terminology used herein is for the purpose of describing particular examples only and is not intended to be limiting. The same reference numbers in different drawings represent the same elements. The numbers provided in the flowcharts and processes are provided for clarity of the steps and operations and do not necessarily indicate a particular order or sequence.

  In the following, a first overview of the technical embodiments is provided, and then specific technical embodiments will be described in more detail later. This first summary is intended to help the reader understand the technology more quickly, and is not intended to identify key features or essential features of the technology, but rather as claimed. It is not intended to limit the scope of the subject matter.

  A coordinated multipoint (CoMP) system may be used to reduce the interference from neighboring nodes in both homogeneous networks and HetNet. In a cooperative multipoint (CoMP) system, nodes, also called collaborating nodes, can be grouped with other nodes. In this case, nodes from multiple cells can transmit signals to the wireless device and receive signals from the wireless device. The cooperating nodes may be nodes in the homogeneous network or macro nodes in HetNet and / or lower power nodes (LPNs). Downlink CoMP transmission is divided into two categories: coordinated scheduling or coordinated beamforming (CS / CB or CS / CBF), as well as joint processing or joint transmission. ) (JP / JT). In CS / CB, a given subframe can be transmitted from one cell to a given wireless device (UE), and coordinated beamforming can be used to control and / or reduce interference between different transmissions. Dynamically coordinate including scheduling among cells. In the case of joint processing, multiple cells may perform joint transmission to the wireless device (UE). In this case, multiple nodes transmit simultaneously with the same time and frequency radio resources and / or dynamic cell selection.

  In non-CoMP systems, timing synchronization at the wireless device (eg, UE) can be performed by using a primary synchronization signal (PSS) and / or a cell specific reference signal (CRS). In downlink (DL) CoMP systems, and in the placement of distributed antennas at different geographic locations, as shown in FIG. 1, the PSS and / or CRS transmission points (eg, macro node 210 in macro cell 212) are physical downlink The timing estimation using PSS and / or CRS is not necessarily the same as the physical downlink shared channel (PDSCH) transmission point (eg, the lower power node [LPN] 220 in LPN cell 222), so It may not be accurate. In the dynamic point selection (DPS) DL CoMP example with common cell identifier (identifier, ID) shown in FIG. 1, the DL transmission 250 (PSS and from the macro node to the wireless device (eg UE 230) And / or the separate DL transmission 260 (including data or PDSCH) from the LPN to the wireless device may be transmitted substantially simultaneously. The DL transmission may arrive at the wireless device at different times due to different geographical locations of nodes (eg, macro nodes and LPNs), and / or other factors. The wireless device may be synchronized to the PSS and / or CRS transmission points (eg, macro nodes).

  For example, orthogonal frequency division multiplexing (OFDM) symbols in macro node transmission 252 and substantially the same OFDM symbols in LPN transmission 262 may be received at different times by wireless devices (eg, UEs) due to propagation delays. The OFDM symbol may include a cyclic prefix (CP). Because the UE is closer to the LPN than the macro node, UE reception of the macro node DL transmission 254 may have a larger propagation delay 256 than the propagation delay 266 of UE reception of the LPN DL transmission 264. If the PSS and / or CRS from the macro node is used for timing synchronization, then the timing of the fast Fourier transform (FFT) window 280 used to sample the OFDMA symbol should be synchronized to the macro node DL transmission Although possible, this transmission may not be the earliest transmission in the coordinated set. As a result, transmissions from other nodes (within the coordinated set) with timing of the OFDM symbol advanced to the FFT sampling window may be applied by the wireless device. Furthermore, in some cases, transmissions from the macro node do not have the strongest signal power (eg, reference signal received power (RSRP)) and / or do not provide data transmission (eg, PDSCH) Sometimes. In these cases, inter-carrier interference (ICI) and inter-symbol interference (ISI) 270 may occur due to incorrect setting of FFT timing in the wireless device. To reduce ICI and ISI and improve OFDMA symbol reception, receiver timing can be adjusted, which can shift the FFT window. Within the FFT window used to receive OFDM symbols, multiple FFT samples of OFDM symbols can be collected. Although macro nodes and LPNs are shown in FIGS. 1-2, any type of node in the DL CoMP system may be used.

  The timing synchronization of the receiver timing of the wireless device may be changed to use the timing estimate generated from the node specific reference signal of the CoMP measurement set. Here, basic timing synchronization uses PSS and / or CRS. The node specific reference signal may include a channel-state information reference signal (CSI-RS). Receiver timing may be receiver internal processing timing, such as when the receiver looks for OFDM symbol boundaries, or when the receiver performs an FFT (eg, samples the OFDM symbol). Since different CSI-RS configurations can be assigned to different geographically separated transmission points (e.g., macro nodes and LPNs), timing estimation can be performed independently for each transmission point. The wireless device may calculate actual timing for data or PDSCH reception from multiple nodes based on multiple timing estimates from the CSI-RS.

  In one example, the wireless device transmits multiple node-specific reference signals (RSs), such as CSI-RS, from multiple cooperating nodes (eg, macro nodes and LPNs) in a coordinated set (eg, CoMP measurement set) of the CoMP system. It can be received. The coordination set may include at least two cooperating nodes. A cooperating node may include a serving node, a macro node or an LPN. The wireless device may receive node-specific RSs from at least two cooperating nodes. The wireless device may generate or calculate the received RS timing for the cooperating node from the node specific RS. The wireless device can estimate composite reception RS timing from the plurality of reception RS timings. The received RS timing may represent timing from at least two cooperating nodes. The wireless device may adjust receiver timing based on combined receive RS timing. The receiver timing to be adjusted may be the time at which the receiver of the wireless device samples, performs or processes the FFT on the received signal or OFDM symbol.

は、ＣｏＭＰ測定セットの全ての算出タイミング

の中で最も早いタイミングに設定することができ、

によって表される。ここで、

は物理ダウンリンク共有チャネル（ＰＤＳＣＨ）タイミングであり、

は、ＣｏＭＰ測定セットのノード毎に算出されたチャネル状態情報基準信号（ＣＳＩ−ＲＳ）タイミングであり、ｍｉｎ（）は最小値関数であり、ｉは、ＣｏＭＰ測定セット内のノードを表す正の整数である（すなわち、ＣｏＭＰ測定セット内にはｉ個のノードが存在する）。無線デバイスにおいては、最も早い受信ＲＳタイミングに基づいて受信機タイミングまたはＦＦＴ窓を調整することで、無線デバイスのＦＦＴサンプリング間隔に対する信号のタイミングの進みを減少させることができる。一例では、最も早い受信ＲＳタイミングを用いた推定複合受信ＲＳタイミングを共同処理（ＪＰ）の共同送信（ＪＰ／ＪＴ）に用いることができ、それにより、ＦＦＴサンプリング間隔は、最も近いノードのＣＳＩ−ＲＳタイミングに対応するよう調整することができる。共同送信（ＪＴ）では、ＰＤＳＣＨは協調セルの複数の協働ノードから送信することができる。 In one embodiment, the wireless device may determine the earliest received RS timing from multiple received RS timings representing various cooperating nodes. The estimated combined receive RS timing used to adjust the receiver timing and / or the FFT window may use or include the earliest receive RS timing 282. The earliest received RS timing may represent the DL transmission with the shortest propagation delay to other cooperating nodes. Estimated combined reception RS timing or actual PDSCH timing

Is all calculated timing of CoMP measurement set

Can be set to the earliest timing of

Represented by here,

Is the physical downlink shared channel (PDSCH) timing,

Is the channel state information reference signal (CSI-RS) timing calculated for each node of the CoMP measurement set, min () is a minimum function, and i is a positive integer representing a node in the CoMP measurement set (Ie, there are i nodes in the CoMP measurement set). In a wireless device, adjusting the receiver timing or FFT window based on the earliest received RS timing can reduce the advance of the timing of the signal relative to the FFT sampling interval of the wireless device. In one example, estimated combined reception RS timing using the earliest reception RS timing can be used for joint processing (JP / JT) for joint processing (JP), so that the FFT sampling interval can be calculated from the CSI of the closest node- It can be adjusted to correspond to the RS timing. In joint transmission (JT), the PDSCH can be transmitted from multiple cooperating nodes in a coordinated cell.

  In another embodiment, the wireless device can determine the minimum received RS timing and the maximum received RS timing from multiple received RS timings representing various cooperating nodes. The estimated combined receive RS timing may be substantially the value between the minimum receive RS timing and the maximum receive RS timing or the receiver RS timing. As shown in FIG. 2, the minimum receive RS timing 362 may include the earliest receive RS timing that represents the DL transmission with the shortest propagation delay to the other cooperating nodes. Maximum receive RS timing 364 may include the latest receive RS timing that represents the DL transmission with the longest propagation delay to other cooperating nodes.

によって表されるＣＳＩ−ＲＳタイミングの加重和を用いて算出することができる。ここで、

は物理ダウンリンク共有チャネル（ＰＤＳＣＨ）タイミングであり、

は、ＣｏＭＰ測定セットの算出されたチャネル状態情報基準信号（ＣＳＩ−ＲＳ）タイミングの各々であり、

はＣＳＩ−ＲＳアンテナポート受信信号電力であり、ｉは、ＣｏＭＰ測定セット内のノードを表す正の整数であり、ｆ（）はその引数（すなわち、関数引数）の単調関数である。ＲＳＲＰに基づいて受信機タイミングまたはＦＦＴ窓を調整することで、最も大きいまたは最も強い信号電力を有するチャネルまたは信号からの受信ＯＦＤＭシンボルに重みまたは優先度を与えることができる。協働ノードのための基準信号受信電力（ＲＳＲＰ）と受信ＲＳタイミングの組み合わせを用いた複合受信ＲＳタイミングは、共同処理（ＪＰ）の動的ポイント選択（ｄｙｎａｍｉｃ ｐｏｉｎｔ ｓｅｌｅｃｔｉｏｎ、ＤＰＳ）または動的セル選択（ｄｙｎａｍｉｃ ｃｅｌｌ ｓｅｌｅｃｔｉｏｎ、ＤＣＳ）の際に用いることができる。動的セル選択（ＤＣＳ）では、ＰＤＳＣＨは、動的に選択することができる、協調セットの単一の協働ノードから送信される。 In another embodiment, the combined receive RS timing used to adjust receiver timing and / or FFT window is generated from reference signal received power (RSRP) for the cooperating node and node specific RS of the cooperating node It can be determined or calculated in combination with the received RS timing. For example, the estimated combined reception RS timing 284 or the actual timing may be

It can be calculated using a weighted sum of CSI-RS timing represented by here,

Is the physical downlink shared channel (PDSCH) timing,

Is each of the calculated channel state information reference signal (CSI-RS) timings of the CoMP measurement set,

Is the CSI-RS antenna port received signal power, i is a positive integer representing a node in the CoMP measurement set, and f () is a monotonic function of its arguments (ie, function arguments). Adjusting the receiver timing or FFT window based on RSRP can give weight or priority to received OFDM symbols from the channel or signal with the largest or strongest signal power. Combined receive RS timing using a combination of reference signal received power (RSRP) and receive RS timing for the co-operating node, dynamic point selection (DPS) or dynamic cell selection of joint processing (JP) It can be used in (dynamic cell selection, DCS). In dynamic cell selection (DCS), PDSCHs are transmitted from a single cooperating node of a coordinated set, which can be selected dynamically.

  In another embodiment, a transmitting cooperating node or controller in the core network selects from a plurality of cooperating nodes a selected cooperating node to use as a reference cooperating node in adjusting receiver timing of the wireless device. Can. The sending collaborating node may be the same or different collaborating node as the selected collaborating node. The transmitting collaborating node may transmit the selection of the selected collaborating node to the wireless device. The wireless device may receive the selection of the selected cooperating node from the cooperating node. Selection of the selected cooperating node may be transmitted or signaled in downlink control information (DCI) directed to the wireless device. A wireless device may receive multiple node-specific RSs from various cooperating nodes. The wireless device may generate synchronous RS timing from the node specific RS from the selected cooperating node. Synchronous RS timing can be used to adjust the receiver timing of the wireless device (for timing synchronization) for received data or a received physical downlink shared channel (PDSCH). The combined receive RS timing can include synchronous RS timing. Thus, cooperating nodes (eg, transmit cooperating nodes) or controllers in the core network select the RS timing to use for composite receive RS timing used to adjust the receiver timing to receive PDSCH. be able to.

  FIG. 3 illustrates two cooperating nodes 310A-B (e.g., first and second collaborating nodes 310A-B transmitting node specific reference signals (NS-RSs) 350A-B to wireless device 330 in cooperating set 320). 1 illustrates coordination of receiver timing of wireless devices in a coordinated multipoint (CoMP) system comprising a working node). The wireless device may be initially synchronized to the PSS and / or CRS transmission points (e.g., second cooperating nodes). For example, the OFDM symbol in the first cooperating node transmission 352B and the substantially the same OFDM symbol in the second cooperating transmission 352A may be received by the wireless device at different times due to propagation delay. Since the wireless device is closer to the first cooperating node than the second cooperating node, wireless device (WD) reception of the second cooperating node (CN) DL transmission 354A is the first cooperation The propagation delay 356A of node (CN) DL transmission 354B may be greater than the propagation delay 356B of wireless device (WD) reception. If PSS and / or CRS from the macro node is used for timing synchronization, then the timing of the fast Fourier transform (FFT) window 380 used to sample the OFDM symbol can be synchronized to the macro node DL transmission. The estimated combined receive RS timing 384 used to adjust the receiver timing and / or FFT window may use or include the earliest receive RS timing or reference signal received power for the cooperating nodes ( It can be determined or calculated by a combination of RSRP) and reception RS timing. The cooperating nodes may transmit node-specific RSs to the wireless device before the wireless device generates received RS timings from multiple cooperating nodes.

  FIG. 4 is another example of synchronizing DL transmission timing of a first cooperating node to downlink transmission of a second cooperating node in a coordinated multipoint (CoMP) system to reduce ICI and ISI Indicates OFDM symbols can be received from two cooperating nodes substantially simultaneously. The adjustment timing 396 can be created at the transmitter timer of the cooperating node, which can shift the Inverse Fast Fourier Transform (IFFT) modulation window. An IFFT modulator or an IFFT module can be used to generate the modulated signal. The wireless device may transmit timing feedback to the first cooperating node, including complex received RS timing, or first cooperating node received RS timing generated from node specific RSs from the first cooperating node. The first cooperating node may receive timing feedback from the wireless device. The first cooperating node may change the downlink transmission timing (e.g., first cooperating node DL transmission 392) with coordinated timing 396 using complex received RS timing or first cooperating node received RS timing. Changing the downlink transmission timing may shift the Inverse Fast Fourier Transform (IFFT) timing of the downlink signal used for the downlink transmission (eg, by combined reception RS timing or first cooperating node reception RS timing). Delay or advance). By varying the reception of the first cooperating node (CN) DL transmission 394 at the wireless device (WD), the time between the minimum receive RS timing and the maximum receive RS timing can be reduced, thereby providing The OFDM symbols can be aligned to reduce ICI and ISI. In another example, downlink transmissions from at least two cooperating nodes in the plurality of cooperating nodes may be received by the wireless device substantially simultaneously. In another example, the DL transmissions of the co-operating node may be coordinated to synchronize the reception of the DL transmissions at the wireless device to designated timing such as existing PSS and / or CRS.

  In another example, the receiver timing of the wireless device may be adjusted using information from node specific RSs from multiple cooperating nodes, and the transmitter timing of at least one cooperating node may provide timing feedback It can be used to adjust to reduce the time between minimum receive RS timing and maximum receive RS timing.

  In one example, as shown in FIG. 5, OFDM symbols and node-specific RSs are between the node (or eNodeB) and the wireless device (or UE) using a general long term evolution (LTE) frame configuration. It may represent an element of radio frame structure transmitted on physical (PHY) layer in downlink transmission or uplink transmission. Although an LTE frame structure is shown, a frame structure for IEEE 802.16 standard (WiMax), IEEE 802.11 standard (WiFi), or another type of communication standard using OFDM may be used.

FIG. 5 shows downlink radio frame configuration type 2. In this example, the radio frame 100 of the signal used to transmit data may be configured to have a duration of 10 milliseconds (milliseconds, ms), T _f . Each radio frame can be segmented or divided into 10 subframes 110i, each 1 ms long. Each subframe, each 0.5ms _period, can be further subdivided into two slots 120a and 120b having a _{T slot.} Each slot for a component carrier (component carrier, CC) used by a transmitting station and a receiving station comprises a plurality of resource blocks (RBs) 130a, 130b, 130i, 130m, and 130n based on CC frequency bandwidth. May be included. The CC can have a carrier frequency with bandwidth and center frequency. Each RB (Physical RB or PRB) 130i includes 12-15 kHz subcarriers 136 (on frequency axis), as well as 6 or 7 orthogonal frequency division multiplexed (OFDM) symbols 132 (on time axis) per subcarrier be able to. The RB may use seven OFDM symbols if a short or standard periodic prefix is used. The RB may use six OFDM symbols if an extended periodic prefix is used. Resource blocks can be mapped to 84 resource elements (REs) 140i using short or standard periodic prefixes, or resource blocks can be mapped to 72 using extended periodic prefixes. It can be mapped to RE (not shown). The RE may be in units of one OFDM symbol 142 per subcarrier (ie, 15 kHz) 146. In the case of quadrature phase-shift keying (QPSK) modulation, each RE can transmit two bits 150a and 150b of information. 16 quadrature amplitude modulation (QAM) or 64 QAM for transmission including many bits by each RE, or two phase shifts for transmission including a few bits (single bit) by each RE Other types of modulation may be used, such as bi-phase shift keying (BPSK) modulation. The RB may be configured for downlink transmission from the eNodeB to the UE, or the RB may be configured for uplink transmission from the UE to the eNodeB.

  The reference signal can be transmitted by means of OFDM symbols via resource elements in the resource block. The reference signal (or pilot signal or tone) may be a known signal used for various reasons, such as timing synchronization, estimation of the channel and / or noise in the channel, and the like. The reference signal can be received and transmitted by the transmitting station and the mobile communication device. Different types of reference signals (RS) can be used in RB. For example, in the LTE system, the types of downlink reference signal include cell specific reference signal (CRS), multicast \ broadcast single-frequency network (MBSFN) reference signal, UE specific reference signal (UE) There may be a unique RS or UE-RS) or a demodulation reference signal (DMRS), a positioning reference signal (PRS), and a channel state information reference signal (CSI-RS).

  The CRS may be transmitted in downlink subframes in cells supporting PDSCH. Data is sent from the eNodeB to the UE via the PDSCH. The MBSFN reference signal may be transmitted when a physical multicast channel (PMCH) is included and transmitted in an MBSFN subframe. The UE-RS or DMRS may be transmitted including in downlink subframes supporting PDSCH. The UE-RS (DMRS) transmits in a resource block allocated for downlink shared channel (DL-SCH) transmission to a specific terminal (eg, mobile communication device), It can be used for beamforming to a single UE using an antenna of and can be used for PDSCH demodulation. The PRS may be sent in RBs in downlink subframes configured for PRS transmission, but may be physical broadcast channel (PBCH), primary synchronization signal (PSS), or secondary synchronization signal (secondary synchronization signal). , SSS) may not be mapped. CSI-RS can be used for downlink channel quality measurement.

  FIG. 6 shows an example flow chart of timing synchronization 560 and additional timing synchronization 580 for downlink (DL) transmission in a coordinated multipoint (CoMP) system. First, PSS and / or CRS from a cooperating node can be used to generate timing estimates 562 for a receiver for a wireless device. A CoMP measurement set configuration 572 may be generated by at least one cooperating node. In another embodiment, the CoMP measurement set configuration 572 may be received from a controller in the core network by at least one cooperating node. At least a segment of the CoMP measurement set configuration can be sent to the wireless device. The segment of the CoMP measurement set sent to the wireless device may include cooperating nodes in a coordinated set used to measure node-specific RSs (eg, CSI-RSs). Additional timing synchronization may be combined from the estimated timing set 582 used to adjust or generate the actual timing of the wireless device receiver as well as the timing estimate 582 for each CSI-RS antenna port in the CoMP measurement set. It may include a calculation 584 of received RS timing.

  In addition to controlling timing synchronization using only PSS, SSS and / or CRS signals, additional timing synchronization is performed using node-specific RS or CSI-RS, so that most of OFDM symbol boundaries are OFDM symbols. It is possible to adjust the receiver timing to receive data OFDM symbols from different cooperating nodes so as to fall within the guard interval, which can reduce ICI and ISI. Receiver timing may include receiver internal processing timing, timing when the receiver looks for OFDM symbol boundaries, or instants when the receiver performs or samples FFT. Additional timing synchronization uses several received reference signal timings from different cooperating nodes instead of just PSS, SSS and / or CRS signals from a single node. Each received reference signal (RS) timing may be from the ith cooperating node. Here, i is a positive integer representing a node in the CoMP measurement set. An OFDM symbol boundary may be in the signal received from the ith cooperating node which may include the serving node. The value of received RS timing can be measured or generated using node-specific RS or CSI-RS from the i-th cooperating node. Timing may include possible delays such as transmitter (TX) delay, propagation delay, receiver (RX) delay, and other processing delays.

  FIG. 7 shows an OFDM demodulator including an FFT demodulator in a receiver (RX) used for downlink in a wireless device, and an OFDM modulation including an IFFT modulator in a transmitter used for downlink in a cooperating node Show the The timing of the FFT demodulator may be adjusted with additional timing synchronization for the OFDM symbol.

  A wireless communication system can be subdivided into various sections called layers. In the LTE system, the communication layer includes a physical (PHY) layer, a media access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (packet data convergence protocol), It may include a PDCP) layer, and a radio resource control (RRC) layer. As shown in FIG. 7, the physical layer may include the basic hardware transmission components of the wireless communication system 400. Although a basic multiple-input multiple-output (MIMO) system is used to clarify the description of the basic hardware transmission components, the components may be complex MIMO systems, It can also be adapted to the SISO system or similar systems. For example, in a MIMO system, transmitter 410 protects binary input data 420 through coding using channel encoder 422, interleaves using interleaver 424 in preparation for fading, and improves mapper 426 to improve reliability. Can be mapped using The mapped data can be separated into layers for the antenna port by transmitter (TX) beamformer 434, and the layers can be OFDM modulated into OFDM symbols using modulators 428A-B. The modulator can use an Inverse Fast Fourier Transform (IFFT) algorithm to calculate an inverse discrete Fourier transform (IDFT) and generate a modulated signal (vector x for each antenna port). The modulated signal can be converted to an analog signal using a digital-to-analog converter (DAC) 430A-B. The analog signal may be transmitted via a radio frequency (RF) transmitter (Tx) 432A-B configured to transmit the signal to transmitter antennas 440A-B operable to transmit the signal. Can. The analog signal will follow the path referred to as channel 450. The physical layer can be a series-to-parallel (S / P) converter, parallel-to-serial (P / S) converter, periodic prefix (CP) inserter and eliminator, guard Other components (not shown) may be included, such as band inserters and removers, as well as other desired components.

  Signals transmitted through channel 450 may be subject to noise 452 and interference 454. The noise and interference are represented as a sum 456 to the channel signal that may be received by receiver antennas 490A-B and one or more radio frequency (RF) receivers (Rx) 482A-B at receiver 460. A channel signal combined with noise and interference can be converted to a digitally modulated signal using an analog-to-digital converter (ADC) 480A-B. The digital signal can be OFDM demodulated using demodulators 478A-B. The demodulator can calculate discrete Fourier transform (DFT) using a fast Fourier transform (FFT) algorithm to generate a demodulated signal (vector y for each antenna port). A channel estimator 462 may use the demodulated signal to estimate channel 450, as well as noise and interference that may occur in the channel. The channel estimator may include or be in communication with a feedback generator. The feedback generator may be a physical uplink shared channel (such as a channel quality indicator (CQI) report, a precoding matrix indicator (PMI) report, or a transmit rank indicator (RI) report). physical uplink shared channel (PUSCH) feedback reports can be generated. The CQI can be used to support the MIMO transmission mode. The demodulated signals may be combined using MIMO decoder 484, demapped using demapper 476, deinterleaved using deinterleaver 474, decoded by channel decoder 472 and used by other layers of the receiving station To generate binary output data 470 that can be

  Another example provides a method 500 of adjusting receiver timing for wireless devices in a coordinated multipoint (CoMP) system, as shown in the flowchart in FIG. The method may be performed on a machine as instructions, where the instructions are included on at least one computer readable medium or one non-transitory machine readable storage medium. The method includes, as at block 510, receiving, at a wireless device, a plurality of node specific reference signals (RSs) from a plurality of cooperating nodes in a coordinated set of the CoMP system. Here, the coordination set includes at least two cooperating nodes. As in block 520, work continues to estimate composite receive RS timing from multiple receive RS timings generated from multiple node-specific RSs. Here, the received RS timing represents the timing from at least two cooperating nodes. The next task of the method may be to adjust the receiver timing based at least in part on the combined received RS timing, as in block 530.

  The node specific RS may include a channel state information reference signal (CSI-RS). The receiver timing to be adjusted may be the time at which the receiver of the wireless device processes the Fast Fourier Transform (FFT) for the received signal.

によって表すことができる。ここで

は物理ダウンリンク共有チャネル（ＰＤＳＣＨ）タイミングであり、

は、ＣｏＭＰ測定セットの算出されたチャネル状態情報基準信号（ＣＳＩ−ＲＳ）タイミングの各々であり、ｍｉｎ（）は最小値関数であり、ｉは、ＣｏＭＰ測定セット内のノードを表す正の整数である。 In one embodiment, the task of estimating the complex receive RS timing may further include selecting the earliest receive RS timing for the complex receive RS timing. Compound reception RS timing is

Can be represented by here

Is the physical downlink shared channel (PDSCH) timing,

Is each of the calculated channel state information reference signal (CSI-RS) timings of the CoMP measurement set, min () is a minimum function, and i is a positive integer representing a node in the CoMP measurement set is there.

によって表すことができる。ここで、

は物理ダウンリンク共有チャネル（ＰＤＳＣＨ）タイミングであり、

は、ＣｏＭＰ測定セットの算出されたチャネル状態情報基準信号（ＣＳＩ−ＲＳ）タイミングの各々であり、

はＣＳＩ−ＲＳアンテナポート基準信号受信電力（ＲＳＲＰ）であり、ｉは、ＣｏＭＰ測定セット内のノードを表す正の整数であり、ｆ（）はその引数の単調関数である。 In another embodiment, the task of estimating combined received RS timing may further include selecting receiver RS timing substantially between the minimum received RS timing and the maximum received RS timing. The minimum receive RS timing may include the timing generated from the node specific RS received first of the first cooperating node, and the maximum received RS timing may be from the node specific RS received at the end of the last cooperating node It may include the timing to be generated. In one example, the combined received RS timing may be determined by a combination of reference signal received power (RSRP) for the cooperating nodes and the received RS timing generated from the node specific RSs of the cooperating nodes. In another example, the composite receive RS timing is

Can be represented by here,

Is the physical downlink shared channel (PDSCH) timing,

Is each of the calculated channel state information reference signal (CSI-RS) timings of the CoMP measurement set,

Is the CSI-RS antenna port reference signal received power (RSRP), i is a positive integer representing a node in the CoMP measurement set, and f () is a monotonic function of its arguments.

  The method may further include the wireless device transmitting timing feedback including combined receive RS timing to the cooperating node. In another example, the method may further include the wireless device transmitting, from the cooperating node, timing feedback including received RS timing generated from the node-specific RS from the cooperating node. The node specific RS may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a cell specific reference signal (CRS), or a channel state information reference signal (CSI-RS).

  Another example is the timing of the downlink (DL) transmission of the first cooperating node relative to the downlink transmission of the second cooperating node in the coordinated multipoint (CoMP) system, as shown in the flow chart in FIG. A method 600 of synchronizing and synchronizing is provided. The method may be performed on a machine as instructions, where the instructions are included on at least one computer readable medium or one non-transitory machine readable storage medium. The method includes an act of receiving timing feedback from a wireless device at a first cooperating node, as indicated at block 610. Here, the timing feedback includes at least one received reference signal (RS) timing generated from node-specific RSs of at least one cooperating node. As in block 620, the task of changing the downlink transmission timing at the first cooperating node continues by adjusting timing with timing feedback.

  The timing feedback includes complex receive RS timing or first cooperating node receive RS timing. The combined receive RS timing can be estimated from multiple received RS timings representing timing from at least two cooperating nodes. The first cooperating node receive RS timing may be generated from the node specific RS from the first cooperating node. The received RS timing can be generated from multiple node-specific RSs.

  In one example, the combined receive RS timing may include a first cooperating node receive RS timing generated from the node-specific RS from the first cooperating node. The node specific reference signal includes a channel state information reference signal (CSI-RS). Downlink transmission includes data or physical downlink shared channel (PDSCH). The task of changing the downlink transmission timing involves shifting the Inverse Fast Fourier Transform (IFFT) timing of the downlink signal used for downlink transmission based on the combined reception RS timing or the first cooperating node reception RS timing. May be included. The method may further include the first cooperating node (e.g., a transmitting cooperating node) selecting a selected cooperating node from the plurality of cooperating nodes. Node-specific RSs from the selected collaborating node can be used by the wireless device to generate synchronous RS timing, which can be used to synchronize received data or receive physical downlink shared channel (PDSCH) timing. It can be used. The first cooperating node may transmit the selection of the selected cooperating node to the wireless device. Synchronous RS timing can be used to adjust the receiver timing of the wireless device for received data or received PDSCH. The method may further include the first cooperating node transmitting a node specific RS to the wireless device prior to receiving timing feedback.

  FIG. 10 shows an example of cooperating nodes 710A-B and an example of wireless device 720 in a coordinated multipoint (CoMP) system. The cooperating nodes may include macro nodes (eg, macro eNBs) or low power nodes (eg, micro eNBs, pico eNBs, femto eNBs, or HeNBs).

  A wireless device 720 (e.g., a UE) may communicate with cooperating nodes 710A-B. The wireless device may include a timing estimation device 718 for estimating receiver timing of wireless devices in a coordinated multipoint (CoMP) system. The timing estimation device may include the downlink reception module 722 and the timing estimator 724. In some embodiments, the timing estimation device may include a timing adjustment module 726 and an uplink (UL) transmission module 728. The wireless device may include a transceiver that receives DL transmission information from the cooperating node and transmits UL transmission information to the cooperating node.

によって表すことができる。ここで、

は物理ダウンリンク共有チャネル（ＰＤＳＣＨ）タイミングであり、

は、ＣｏＭＰ測定セットの算出されたチャネル状態情報基準信号（ＣＳＩ−ＲＳ）タイミングの各々であり、ｍｉｎ（）は最小値関数であり、ｉは、ＣｏＭＰ測定セット内のノードを表す正の整数である。別の例では、タイミング推定器は、複合受信ＲＳタイミングを用いて実質的に最小受信ＲＳタイミングと最大受信ＲＳタイミングとの間の受信機ＲＳタイミングを選択するように構成することができる。別の例では、タイミング推定器は、協働ノードのための基準信号受信電力（ＲＳＲＰ）と、協働ノードのノード固有ＲＳから生成された受信ＲＳタイミングとの組み合わせから複合受信ＲＳタイミングを求めるよう構成することができる。複合受信ＲＳタイミングは、

によって表される。ここで、

は物理ダウンリンク共有チャネル（ＰＤＳＣＨ）タイミングであり、

は、ＣｏＭＰ測定セットの算出されたチャネル状態情報基準信号（ＣＳＩ−ＲＳ）タイミングの各々であり、

はＣＳＩ−ＲＳアンテナポート基準信号受信電力（ＲＳＲＰ）であり、ｉは、ＣｏＭＰ測定セット内のノードを表す正の整数であり、ｆ（）はその引数の単調関数である。 The downlink reception module 722 may be configured to receive node specific reference signals (RSs) from multiple cooperating nodes in the coordinated set of the CoMP system at the wireless device. The coordination set may include at least two cooperating nodes. The downlink reception module may be further configured to receive a selection of selected collaborating nodes. The selected collaborating node may be a controller in the core network, or a collaborating node may select from a plurality of collaborating nodes. Node-specific RSs from the selected collaborating node can be used by the wireless device to generate synchronous RS timing, which may be timing synchronization for received data or receive physical downlink shared channel (PDSCH) or It can be used to adjust the receiver timing of the wireless device. The timing estimator 724 can be configured to estimate a combined received RS timing from multiple received RS timings generated from multiple node-specific RSs. The received RS timing may represent timing from at least two cooperating nodes. The node specific RS includes a channel state information reference signal (CSI-RS). In one example, the timing estimator may be configured to select the earliest received RS timing as the combined received RS timing. Compound reception RS timing is

Can be represented by here,

Is the physical downlink shared channel (PDSCH) timing,

Is each of the calculated channel state information reference signal (CSI-RS) timings of the CoMP measurement set, min () is a minimum function, and i is a positive integer representing a node in the CoMP measurement set is there. In another example, the timing estimator may be configured to select receiver RS timing between substantially minimum received RS timing and maximum received RS timing using combined received RS timing. In another example, the timing estimator determines the combined received RS timing from the combination of the reference signal received power (RSRP) for the co-operating node and the received RS timing generated from the node-specific RS of the co-operating node It can be configured. Compound reception RS timing is

Represented by here,

Is the physical downlink shared channel (PDSCH) timing,

Is each of the calculated channel state information reference signal (CSI-RS) timings of the CoMP measurement set,

Is the CSI-RS antenna port reference signal received power (RSRP), i is a positive integer representing a node in the CoMP measurement set, and f () is a monotonic function of its arguments.

  The timing adjustment module 726 can be configured to adjust receiver timing based on combined receive RS timing. The receiver timing to be adjusted may be the time at which the receiver of the wireless device processes the Fast Fourier Transform (FFT) for the received signal. Time may represent the boundaries of the FFT window. The uplink transmission module 728 may be configured to transmit timing feedback to the cooperating nodes, including complex received RS timings, or received RS timing generated from node-specific RSs from the cooperating nodes. A wireless device may include user equipment (UE) and a mobile station (MS). The wireless device may be at least one of a wireless local area network (WLAN), a wireless personal area network (WPAN), and a wireless wide area network (WWAN). It can be connected. The wireless device may include an antenna, a touch sensitive display screen, a speaker, a microphone, a graphics processor, an application processor, an internal memory, or a non-volatile memory port.

  Each cooperating node 710A-B is timing for synchronizing the timing of the downlink (DL) transmission of the first cooperating node to the downlink transmission of the second cooperating node in the coordinated multipoint (CoMP) system Synchronization devices 708A-B may be included. The timing synchronization device may include downlink transmission modules 712A-B, uplink reception modules 714A-B, and timing change modules 716A-B. In one example, the timing synchronization device may include a selection module (not shown). In another example, the selection module can be included in a controller in the core network. The collaborating nodes are within the collaborative set 740 of the CoMP system and can communicate with one another via the backhaul link 750. The backhaul link may include wired connection, wireless connection, or X2 signaling or backhaul link signaling via fiber optic connection. Communication between cooperating nodes may include CoMP measurement set information.

  Uplink reception modules 714A-B may be configured to receive timing feedback from the wireless device. The timing feedback may include at least one received reference signal (RS) timing generated from node-specific RSs of at least one cooperating node. The timing feedback may include complex receive reference signal (RS) timing or first cooperating node receive RS timing. The composite receive RS timing can be estimated from multiple receive RS timings representing timing from at least two cooperating nodes, and the receive RS timing can be generated from multiple node specific RSs. The first cooperating node receive RS timing may be generated from the node specific RS from the first cooperating node. The timing change modules 716A-B may be configured to change the downlink transmission timing at the first cooperating node by adjusting timing with timing feedback. The node specific reference signal includes a channel state information reference signal (CSI-RS). The timing change module may be further configured to shift the fast inverse Fourier transform (IFFT) timing of the downlink signal used for downlink transmission by combined reception RS timing or cooperating node reception RS timing. Downlink transmission modules 712A-B may be configured to transmit node-specific RSs to wireless devices. The selection module may be configured to select the selected collaborating node from the plurality of collaborating nodes. Node-specific RSs from the selected collaborating node can be used by the wireless device to generate synchronous RS timing, which can be used to synchronize received data or receive physical downlink shared channel (PDSCH) timing. It can be used. The downlink transmission module may be further configured to transmit the selection of the selected cooperating node to the wireless device. Synchronous RS timing can be used to adjust the receiver timing of the wireless device for received data or received PDSCH. A cooperating node may include a macro node, a low power node (LPN), a macro evolved Node B (macro eNB), a micro eNB, a pico eNB, a femto eNB, or a home eNB (HeNB).

  FIG. 11 provides an illustration of an example wireless device, such as a user equipment (UE), a mobile station (MS), a mobile wireless device, a mobile communication device, a tablet, a handset, or other type of mobile wireless device. The wireless device includes a base station (BS), an evolved Node B (eNB), a base band unit (BBU), a remote radio head (RRH), and a remote radio equipment (RRE). Macro nodes, low power nodes (LPNs), transmitting stations etc., such as relay stations (RS), radio equipment (RE), or other types of wireless wide area network (WWAN) access points May include one or more antennas in communication with the The wireless device may be configured to communicate using at least one wireless communication standard, including 3GPP LTE, WiMAX, High Speed Packet Access (HSPA), Bluetooth, and WiFi. Can. The wireless devices may communicate using independent antennas for each wireless communication standard or shared antennas for multiple wireless communication standards. A wireless device may communicate within a wireless local area network (WLAN), a wireless personal area network (WPAN), and / or a WWAN.

  FIG. 11 also provides an illustration of a microphone and one or more speakers that can be used for audio input to and output from a wireless device. The display screen may be a liquid crystal display (LCD) screen, or another type of display screen such as an organic light emitting diode (OLED) display. The display screen can be configured as a touch screen. The touch screen may use capacitive, resistive, or another type of touch screen technology. An application processor and a graphics processor can be coupled to internal memory to provide processing and display functionality. Non-volatile memory ports can also be used to provide data input / output options to the user. Non-volatile memory ports may be used to expand the memory capabilities of the wireless device. A keyboard may be integrated with or wirelessly connected to the wireless device to provide additional user input. A virtual keyboard may be provided using a touch screen.

  Various techniques, or portions of aspects or portions thereof, may be tangible, such as floppy diskettes, CD-ROMs, hard drives, non-transitory computer readable storage media, or any other machine readable storage media. The program code may be in the form of program code (i.e., instructions) embodied in the form of a medium, which, when loaded into a machine such as a computer and executed thereby, causes the machine to implement various techniques. Become. For program code execution on a programmable computer, the computing device comprises a processor, a storage medium readable by the processor (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one. May include one output device. Volatile and non-volatile memory and / or storage elements may be RAM, EPROM, flash drive, optical drive, magnetic hard drive, or other medium for electronic data storage. Base stations and wireless devices may include transceiver modules, counter modules, processing modules, and / or clock modules or timer modules. One or more programs that may implement or utilize the various techniques described herein may use an application programming interface (API), reusable controls, and the like. Such programs may be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the program (s) may be implemented in assembly or machine language, if desired. In any case, the language is a compiled or interpreted language and may be combined with a hardware implementation.

  It should be understood that many of the functional units described herein are labeled as modules to more specifically emphasize their implementation independence. For example, the module may be implemented as a hardware circuit including custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. The modules may be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

  The modules may be implemented in software for execution by various types of processors. A particular module of executable code may, for example, comprise one or more physical or logical blocks of computer instructions, which may, for example, be organized as an object, procedure, or function. However, the executable files of a particular module do not have to be physically located together, but when logically combined, they are stored in different locations, which constitute the module and achieve the stated purpose for the module. May contain different types of instructions.

  In fact, the module of executable code may be a single instruction or a large number of instructions, and furthermore, across several different code segments, between different programs, and several memories. It may be distributed across devices. Similarly, operational data may be identified and shown in modules herein, but may be embodied in any suitable form and organized in any suitable type of data structure. Operational data may be aggregated as a single data set, or may be distributed across different locations, eg, across different storage devices, or even at least partially as electronic signals on a system or network Good. The module may be passive or it may be active, including an agent operable to perform the desired function.

  References to "an example" throughout this specification mean that the specific features, structures or characteristics described for that example are included in at least one embodiment of the present invention. Thus, the appearances of the phrase "in an example" in various places throughout the specification are not necessarily all referring to the same embodiment.

  As used herein, multiple items, structural elements, components, and / or materials may be presented in a common list for convenience. However, these lists should be construed as though each element of the list is specified as a separate and unique element. Therefore, all individual elements of such a list are, unless otherwise indicated, the fact of any other element of the same list solely on the basis that they are presented in a common group It should not be interpreted as the above equivalent. In addition, various embodiments and examples of the present invention may be referred to herein along with alternatives to their various components. It should be understood that such embodiments, examples, and alternatives should not be construed as practical equivalents of one another, but rather as being considered as separate autonomous representatives of the present invention.

  Furthermore, the features, structures, or characteristics described above may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of layouts, distances, example networks, etc., in order to provide a thorough understanding of embodiments of the present invention. However, one skilled in the art will understand that the invention may be practiced without one or more of the specific details, or with other methods, components, layouts, etc. In other instances, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring aspects of the invention.

によって表され、ここで、

は、物理ダウンリンク共有チャネル（ＰＤＳＣＨ）タイミングであり、

は、ＣｏＭＰ測定セットの算出されたチャネル状態情報基準信号（ＣＳＩ−ＲＳ）タイミングの各々であり、ｍｉｎ（）は最小値関数であり、ｉは、前記ＣｏＭＰ測定セット内のノードを表す正の整数である、項目１３に記載の装置。
（項目１５）
前記１つまたは複数のプロセッサは、実質的に最小受信ＲＳタイミングと最大受信ＲＳタイミングとの間の受信機ＲＳタイミングを選択するように構成される、項目８から１１のいずれか一項に記載の装置。
（項目１６）
前記複合受信ＲＳタイミングは、

によって表され、ここで、

は、物理ダウンリンク共有チャネル（ＰＤＳＣＨ）タイミングであり、

は、ＣｏＭＰ測定セットの算出された複数のチャネル状態情報基準信号（ＣＳＩ−ＲＳ）タイミングの各々であり、

は、ＣＳＩ−ＲＳアンテナポート基準信号受信電力（ＲＳＲＰ）であり、ｉは、前記ＣｏＭＰ測定セット内のノードを表す正の整数であり、ｆ（）は関数引数の単調関数である、項目１５に記載の装置。
（項目１７）
前記１つまたは複数のプロセッサは、前記複合受信ＲＳタイミングを含み、協調ノードへ送信するためのタイミングフィードバックを処理するように更に構成される、項目８から１６のいずれか一項に記載の装置。
（項目１８）
前記ＵＥは、無線ローカルエリアネットワーク（ＷＬＡＮ）、無線パーソナルエリアネットワーク（ＷＰＡＮ）、または無線ワイドエリアネットワーク（ＷＷＡＮ）に接続され、前記ＵＥは、アンテナ、タッチセンシティブディスプレイ画面、スピーカ、マイクロホン、グラフィックスプロセッサ、アプリケーションプロセッサ、内部メモリ、または、不揮発性メモリポートを含む、項目８から１７のいずれか一項に記載の装置。
（項目１９）
協調マルチポイント構成（ＣｏＭＰ構成）において、第２の協調ノードのダウンリンク送信（ＤＬ送信）に対して第１協調ノードのダウンリンク送信のタイミングを同期させるための複数の命令が実装された少なくとも１つの機械可読記憶媒体であって、前記複数の命令は、前記第１協調ノードの１つまたは複数のプロセッサに、
前記第１協調ノードにおいて、ユーザ設備（ＵＥ）から受信したタイミングフィードバックを処理することと、
前記タイミングフィードバックを用いて調整タイミングにしたがって前記第１協調ノードにおけるダウンリンク送信タイミングを変更することと
を実行させ、
前記タイミングフィードバックは、少なくとも１つの協調ノードのノード固有ＲＳから生成された少なくとも１つの受信基準信号（ＲＳ）タイミングを含む、機械可読記憶媒体。
（項目２０）
前記タイミングフィードバックは複合受信ＲＳタイミングまたは前記第１協調ノードの受信ＲＳタイミングを含み、前記複合受信ＲＳタイミングは、少なくとも２つの協調ノードからのタイミングを表す複数の受信ＲＳタイミング、または、前記第１協調ノードからの複数のノード固有ＲＳから生成する第１協調ノード受信ＲＳタイミングから推定され、前記複数の受信ＲＳタイミングは、前記複数のノード固有ＲＳから生成する、項目１９に記載の少なくとも１つの機械可読記憶媒体。
（項目２１）
前記複合受信ＲＳタイミングは、前記少なくとも２つの協調ノードについてのアンテナポートによって受信したＲＳの間の複合タイミング遅延を表し、前記複合タイミング遅延は、送信機遅延（ＴＸ遅延）、伝搬遅延、受信機遅延（ＲＸ遅延）または他の処理遅延の１または複数を含む、項目２０に記載の少なくとも１つの機械可読記憶媒体。
（項目２２）
前記ノード固有ＲＳは、チャネル状態情報基準信号（ＣＳＩ−ＲＳ）を含み、前記ダウンリンク送信は、データまたは物理ダウンリンク共有チャネル（ＰＤＳＣＨ）を含む、項目１９から２１のいずれか一項に記載の少なくとも１つの機械可読記憶媒体。
（項目２３）
前記ダウンリンク送信タイミングを変更することは、複合受信ＲＳタイミングまたは前記第１協調ノードの受信ＲＳタイミングによって、前記ダウンリンク送信に用いられるダウンリンク信号の高速逆フーリエ変換タイミング（ＩＦＦＴタイミング）をシフトさせることを更に含み、
前記ＩＦＦＴタイミングをシフトさせることは、前記ＩＦＦＴタイミングを遅延させることまたは進めることを含む、項目１９に記載の少なくとも１つの機械可読記憶媒体。
（項目２４）
前記タイミングフィードバックを受信する前に、
前記第１協調ノードにおいて、複数の協調ノードから選択協調ノードを選択することと、
前記ＵＥへの送信のために、前記選択協調ノードの選択を処理することと、
ダウンリンク送信に対応付けられているチャネル状態情報基準信号（ＣＳＩ−ＲＳ）アンテナポートを用いて、前記第１協調ノードから前記ＵＥへの送信のために、ノード固有ＲＳを処理することと
を実行させる複数の命令を更に備え、
前記選択協調ノードからのノード固有ＲＳは、前記ＵＥによって同期ＲＳタイミングを生成するために用いられ、前記同期ＲＳタイミングは受信データまたは受信物理ダウンリンク共有チャネル（受信ＰＤＳＣＨ）のためのタイミング同期に用いられ、
前記同期ＲＳタイミングは、前記ＵＥの受信機タイミングを受信データまたは前記受信ＰＤＳＣＨのために調整するために用いられ、
前記ダウンリンク送信は、データまたは物理ダウンリンク共有チャネル（ＰＤＳＣＨ）を含む、項目１９に記載の少なくとも１つの機械可読記憶媒体。
While the above examples are illustrative of the principles of the invention in one or more specific applications, aspects, uses, and implementations may be made without departing from the principles and concepts of the invention without exerting inventiveness. It will be apparent to those skilled in the art that numerous changes in the details of can be made. Accordingly, it is not intended to limit the invention except by the claims defined below.
(Item 1)
At least one machine readable storage medium implemented with a plurality of instructions for adjusting receiver timing of user equipment (UE) in a coordinated multipoint configuration (CoMP configuration), the plurality of instructions being the UE On one or more processors of
Processing a plurality of node-specific reference signals (RSs) received from the plurality of nodes in the CoMP configuration at the UE;
Generating multiple node-specific RS timings received by the antenna port for at least two nodes;
Estimating a composite timing delay from the plurality of received node-specific RS timings;
Adjusting the receiver timing of the UE based on at least a portion of the combined timing delay;
A machine readable storage medium that causes
(Item 2)
The plurality of node-specific RSs are received using a channel state information reference signal (CSI-RS) antenna port associated with downlink transmission, and the downlink transmission may be a data or physical downlink shared channel (PDSCH) And at least one machine readable storage medium according to claim 1.
(Item 3)
3. At least one machine readable storage medium according to item 1 or 2, wherein the node specific RS comprises a channel state information reference signal (CSI-RS).
(Item 4)
The at least one machine-readable of any of the preceding claims, wherein the receiver timing to be adjusted indicates the time at which the receiver of the UE processes a Fast Fourier Transform (FFT) for the received signal. Storage medium.
(Item 5)
The node-specific RS is at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a cell-specific reference signal (CRS), or a channel state information reference signal (CSI-RS). One machine readable storage medium.
(Item 6)
6. At least one machine readable storage medium according to any one of items 1 to 5, wherein the plurality of nodes are a plurality of coordination nodes.
(Item 7)
6. The at least one according to any one of items 1 to 5, wherein the composite timing delay comprises one or more of transmitter delay (TX delay), propagation delay, receiver delay (RX delay) or other processing delay. Machine readable storage medium.
(Item 8)
A user equipment (UE) apparatus capable of estimating receiver timing in a coordinated multipoint configuration (CoMP configuration),
With memory
With one or more processors
Equipped with
The one or more processors may be
Processing a plurality of node-specific reference signals (RSs) received from the plurality of coordination nodes in the coordination set of the CoMP configuration in the UE;
Configured to estimate a composite reception RS timing from a plurality of reception RS timings generated from the plurality of node-specific RSs,
The apparatus wherein the plurality of node-specific RSs are received using a channel state information reference signal (CSI-RS) antenna port associated with downlink transmission.
(Item 9)
The combined receive RS timing represents a combined timing delay between RSs received by multiple antenna ports for at least two coordinating nodes, the combined timing delay being a transmitter delay (TX delay), a propagation delay, a receiver 9. Apparatus according to item 8, comprising one or more of a delay (RX delay) or other processing delay.
(Item 10)
10. The apparatus according to item 8 or 9, wherein the plurality of node specific RSs are received using a transmission mode for CoMP configuration.
(Item 11)
11. The apparatus according to any one of items 8 to 10, wherein the one or more processors are further configured to adjust the receiver timing based on the composite received RS timing.
(Item 12)
11. The apparatus of clause 11, wherein the receiver timing to be adjusted is the time at which the receiver of the UE processes a Fast Fourier Transform (FFT) for the received signal.
(Item 13)
13. The apparatus as in any one of items 8-12, wherein the one or more processors are further configured to select an earliest received RS timing for the combined received RS timing.
(Item 14)
The composite reception RS timing is

Represented by, where

Is the physical downlink shared channel (PDSCH) timing,

Is each of the calculated channel state information reference signal (CSI-RS) timings of the CoMP measurement set, min () is a minimum value function, and i is a positive integer representing a node in the CoMP measurement set The device according to item 13, which is
(Item 15)
12. The one or more processors according to any one of items 8 to 11, wherein the one or more processors are configured to select receiver RS timing substantially between the minimum received RS timing and the maximum received RS timing. apparatus.
(Item 16)
The composite reception RS timing is

Represented by, where

Is the physical downlink shared channel (PDSCH) timing,

Are the calculated multiple channel state information reference signal (CSI-RS) timings of the CoMP measurement set,

Is the CSI-RS antenna port reference signal received power (RSRP), i is a positive integer representing a node in the CoMP measurement set, and f () is a monotonic function of the function argument, item 15 Device described.
(Item 17)
17. The apparatus according to any one of items 8 to 16, wherein the one or more processors include the combined receive RS timing and are further configured to process timing feedback for transmission to a coordinating node.
(Item 18)
The UE is connected to a wireless local area network (WLAN), a wireless personal area network (WPAN), or a wireless wide area network (WWAN), and the UE comprises an antenna, a touch sensitive display screen, a speaker, a microphone, a graphics processor 18. An apparatus according to any one of items 8 to 17, including an application processor, an internal memory, or a non-volatile memory port.
(Item 19)
In a cooperative multipoint configuration (CoMP configuration), at least one of a plurality of instructions implemented to synchronize timing of downlink transmission of the first cooperative node with downlink transmission (DL transmission) of the second cooperative node One machine readable storage medium, the plurality of instructions being to one or more processors of the first coordinating node;
Processing timing feedback received from user equipment (UE) at the first coordinating node;
Changing the downlink transmission timing at the first coordinating node according to the adjustment timing using the timing feedback
To run
The machine readable storage medium, wherein the timing feedback comprises at least one received reference signal (RS) timing generated from a node specific RS of at least one coordinating node.
(Item 20)
The timing feedback includes combined reception RS timing or reception RS timing of the first coordination node, and the combination reception RS timing is a plurality of reception RS timings representing timing from at least two coordination nodes, or the first coordination 20. At least one machine-readable device according to item 19, estimated from a first cooperative node reception RS timing generated from a plurality of node specific RSs from a node, the plurality of reception RS timings generated from the plurality of node specific RSs Storage medium.
(Item 21)
The combined receive RS timing represents the combined timing delay between RSs received by the antenna port for the at least two coordinating nodes, the combined timing delay comprising: transmitter delay (TX delay), propagation delay, receiver delay 21. At least one machine readable storage medium according to item 20, comprising one or more of (RX delay) or other processing delays.
(Item 22)
22. The node-specific RS comprises a channel state information reference signal (CSI-RS) and the downlink transmission comprises data or physical downlink shared channel (PDSCH) according to any one of items 19 to 21 At least one machine readable storage medium.
(Item 23)
Changing the downlink transmission timing shifts the fast inverse Fourier transform timing (IFFT timing) of the downlink signal used for the downlink transmission according to the combined reception RS timing or the reception RS timing of the first cooperation node. Further include
21. At least one machine readable storage medium according to item 19, wherein shifting the IFFT timing comprises delaying or advancing the IFFT timing.
(Item 24)
Before receiving the timing feedback
Selecting a selected coordination node from a plurality of coordination nodes at the first coordination node;
Processing the selection of the selected coordination node for transmission to the UE;
Processing a node-specific RS for transmission from the first coordinating node to the UE using a channel state information reference signal (CSI-RS) antenna port associated with downlink transmission;
Further comprising a plurality of instructions to execute
Node-specific RS from the selected coordinating node is used by the UE to generate synchronous RS timing, which is used for timing synchronization for received data or received physical downlink shared channel (received PDSCH) And
The synchronous RS timing is used to adjust the receiver timing of the UE for received data or the received PDSCH,
The at least one machine readable storage medium of item 19, wherein the downlink transmission comprises data or physical downlink shared channel (PDSCH).

Claims (21)

At least one machine readable storage medium implemented with a plurality of instructions for adjusting receiver timing of user equipment (UE) in a coordinated multipoint configuration (CoMP configuration), the plurality of instructions being the UE On one or more processors of
Processing a plurality of channel state information reference signals (CSI-RSs) received from a plurality of cooperating nodes at the UE , wherein the plurality of cooperating nodes are included in a coordinated set of the CoMP configuration and that,
Generating a plurality of received RS timings from the plurality of CSI-RSs , wherein the plurality of received RS timings represent timings from the plurality of cooperating nodes ;
From the plurality of received RS timing, the method comprising: obtaining a composite received RS timing, the composite receiver RS timing transmitter (TX) delay, from said plurality of cooperating nodes included in the coordinated set of the CoMP system Determining, including one or more of a received CSI-RS propagation delay or a receiver (RX) delay ;
Adjusting the receiver timing of the UE based on at least a portion of the composite received RS timing . The plurality of CSI-RSs are received using a CSI-RS antenna port associated with downlink transmission, and the downlink transmission includes data or physical downlink shared channel (PDSCH). At least one machine-readable storage medium according to claim 1. The at least one machine readable storage medium according to claim 1 or 2 , wherein the receiver timing to be adjusted indicates the time at which the receiver of the UE processes a Fast Fourier Transform (FFT) for the received signal.   The UE may further comprise instructions for causing the one or more processors of the UE to determine the combined receive RS timing based on the earliest received RS timing, the earliest received RS timing being the plurality of cooperating 4. At least one machine readable storage medium according to any one of the preceding claims, received from one of the nodes.   Performing, on the one or more processors of the UE, determining the combined receive RS timing substantially based on selecting a receiver RS timing between a minimum receive RS timing and a maximum receive RS timing; 5. At least one machine readable storage medium according to any of the claims 1-4, further comprising instructions for causing.   Performing, on the one or more processors of the UE, determining the combined reception RS timing using a combination of reference signal received power (RSRP) for the plurality of cooperating nodes and the plurality of received RS timings 6. At least one machine readable storage medium according to any one of the preceding claims, further comprising instructions for causing.   On said one or more processors of said UE,
  Encoding timing feedback for transmission to a cooperating node of the plurality of cooperating nodes including the complex receive RS timing;
  The method further comprises an instruction to execute encoding received RS timing for transmission, wherein the received RS timing is generated only from CSI-RS from the one cooperating node of the plurality of cooperating nodes 7. At least one machine readable storage medium according to any one of the preceding claims. A user equipment (UE) apparatus capable of estimating receiver timing in a coordinated multipoint configuration (CoMP configuration),
With memory
And one or more processors,
The one or more processors may be
The method comprising processing a plurality of channel state information reference signal received from a plurality of cooperating nodes in cooperation set of the CoMP configuration in the UE (CSI-RS), wherein the plurality of CSI-RS is downlink transmission Perform processing, received using the CSI-RS antenna port associated with
Estimating complex reception RS timing from a plurality of reception RS timings generated from the plurality of CSI-RSs , wherein the complex reception RS timing is a transmitter (TX) delay, within the cooperative set of the CoMP system An apparatus for performing estimation , including one or more of CSI-RS propagation delays or receiver (RX) delays received from the plurality of cooperating nodes included . Wherein the plurality of CSI-RS is received using the transmission mode for the CoMP configuration, apparatus according to claim 8. 10. The apparatus of claim 8 or 9 , wherein the one or more processors further adjust the receiver timing based on the combined received RS timing. The apparatus according to any one of claims 8 to 10, wherein the receiver timing to be adjusted is the time at which the receiver of the UE processes a Fast Fourier Transform (FFT) for the received signal. The apparatus according to any one of claims 8 to 11 , wherein the one or more processors further select the earliest received RS timing as the combined received RS timing. 13. The apparatus according to any one of claims 8 to 12 , wherein the one or more processors further select receiver RS timing between substantially minimum received RS timing and maximum received RS timing. 14. The processor according to any one of claims 8 to 13 , wherein the one or more processors further include the composite receive RS timing and process timing feedback for transmission to a cooperating node of one of the plurality of cooperating nodes. A device according to any one of the preceding claims. The UE is connected to a wireless local area network (WLAN), a wireless personal area network (WPAN), or a wireless wide area network (WWAN), and the UE comprises an antenna, a touch sensitive display screen, a speaker, a microphone, a graphics processor The apparatus according to any one of claims 8 to 14 , comprising an application processor, an internal memory or a non-volatile memory port.   A user equipment (UE) operable to adjust receiver timing, said UE being
  A transceiver for receiving a plurality of channel state information reference signals (CSI-RSs) from a plurality of cooperating nodes, the plurality of cooperating nodes being included in a coordinated set of a coordinated multipoint (CoMP) system;
  Generating a plurality of reception RS timings representing timings from the plurality of cooperating nodes from the plurality of CSI-RSs;
  Including one or more of transmitter (TX) delay, propagation delay of CSI-RS received from the plurality of cooperating nodes included in the cooperating set of the CoMP system, or receiver (RX) delay The complex reception RS timing is determined from the plurality of reception RS timings,
  One or more processors that adjust the receiver timing based on the combined receive RS timing;
  UE comprising.   17. The UE of claim 16, wherein the one or more processors further determine the combined received RS timing based on an earliest received RS timing received from one of the plurality of cooperating nodes.   The UE according to claim 16 or 17, wherein the receiver timing to be adjusted is the time at which the receiver of the UE processes a Fast Fourier Transform (FFT) for the received RS.   19. The one or more processors further determine the combined reception RS timing based on selecting a receiver RS timing substantially between the minimum reception RS timing and the maximum reception RS timing. UE according to any one of the items.   The one or more processors further determine the combined reception RS timing using a combination of a reference signal received power (RSRP) for the plurality of cooperating nodes and the plurality of received RS timings. The UE according to any one of to 19.   21. The transceiver according to claim 16 to 20, further transmitting timing feedback including the combined reception RS timing to a cooperating node, or transmitting reception RS timing generated only from CSI-RS from the cooperating node. UE according to any one of the items.

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