Signaling configuration for indicating DMRS ports that are co-scheduled in MU-MIMO

Abstract

To provide a base station and a method for transmitting and receiving data and / or reference signals on resources.SOLUTION: In a communication system, a base station 260 transmits parameters defining a configuration for allocating each resource for carrying a reference signal to a port. Control information indicates cooperative scheduling information, and each resource includes two resource element configurations. The base station further transmits to a mobile terminal 210 an indicator indicating whether a first resource element configuration or a second resource element configuration is used.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This disclosure relates to the transmission and reception of data and / or reference signals on resources of a communication system.

Background Art

[0002] Currently, the 3rd Generation Partnership Project (3GPP) is working towards the public release (Release 15) of the technical specifications of the next-generation cellular technology, also known as the 5th Generation (5G). At the 3GPP Technical Specification Group (TSG) Radio Access Network (RAN) meeting No. 71 (Gutenberg, March 2016), the first 5G study item, "Study on New Radio Access Technology", including RAN1, RAN2, RAN3 and RAN4, was approved and is expected to become the Release 15 work item that defines the first 5G standard.

[0003] One of the objectives of 5G NR is to provide a single technical framework that addresses all usage scenarios, requirements and deployment scenarios defined in Non-Patent Document 1 (available at www.3gpp.org), including at least enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC).

[0004] For example, eMBB deployment scenarios can include indoor hotspots, dense urban areas, rural areas, urban macro and high speed, URLLC deployment scenarios can include industrial control systems, mobile health management (remote monitoring, diagnosis and treatment), vehicle real-time control, wide area monitoring, and smart grid control systems, and mMTC can include scenarios that use a large number of devices for non-time-critical data transfer, such as smart wearables and sensor networks.

[0005] Another objective is to ensure backward compatibility. Backward compatibility with Long Term Evolution (LTE) is not required, which facilitates the introduction of entirely new system designs and / or new features.

[0006] As summarized in one of the technical reports on NR work items (Non-Patent Literature 2), the basic physical layer signal waveform will be based on orthogonal frequency division multiplexing (OFDM). Waveforms based on OFDM with cyclic prefixes (CP-OFDM) are supported for both downlink and uplink. Waveforms based on discrete Fourier transform (DFT) spread OFDM (DFT-S-OFDM), which are complementary to CP-OFDM up to 40 GHz for eMBB uplinks, are also supported.

[0007] One of the design goals of NR is to find a waveform that is as common as possible for downlink, uplink, and sidelink. It has been thought that introducing DFT spreading may not be necessary in some cases for uplink transmissions. The term "downlink" refers to communication from a higher node to a lower node (for example, from a base station to a relay node or UE, or from a relay node to a UE, etc.). The term "uplink" refers to communication from a lower node to a higher node (for example, from a UE to a relay node or base station, or from a relay node to a base station, etc.). The term "sidelink" refers to communication between nodes at the same level (for example, between two UEs, or between two relay nodes, or between two base stations).

[0008] In terminology, a spatial layer (or layer) refers to one of the different streams generated by spatial multiplexing. A single layer can be described as a mapping of symbols to a transmitting antenna port. Each layer is identified by a precoding vector equal in size to the number of transmitting antenna ports and can be associated with a single radiation pattern. The rank of transmission is the number of layers being transmitted. A codeword is a separately encoded data block corresponding to a single transport block (TB) sent from the transmitter's Medium Access Control (MAC) layer to the physical layer and protected by cyclic redundancy check (CRC).

[0009] Generally, one layer is assigned to each Transmit Time Increment (TTI) interval, which corresponds to an LTE subframe. However, in 3GPP NR, different TTIs are possible depending on whether URLLC or eMBB is used. In particular, in NR, the TTI can be a slot, a minislot, or a subframe. See also Non-Patent Document 3 for information on layers, ranks, and codewords.

[0010] Traditionally, a reference signal pattern (RS) is transmitted from a base station's antenna port (or port). The port can transmit as a single physical transmitting antenna or as a combination of multiple physical antenna elements. In either case, the signals transmitted from each antenna port are not designed to be further decomposed by the UE receiver. That is, the transmitted RS corresponding to a given antenna port defines the antenna port from the UE's perspective, enabling the UE to obtain channel estimates for all data transmitted at that antenna port, regardless of whether those channel estimates represent a single radio channel from a single physical antenna or a composite channel from multiple physical antenna elements including that antenna port. See also Non-Patent Document 4 for more information on ports.

[0011] In LTE, data transmission and reception by the UE is scheduled by the eNB using a physical downlink control channel (PDCCH), which carries messages called downlink control information (DCI), containing resource allocation and other control information for the UE or group of UEs. Generally, several PDCCHs can be transmitted in subframes.

[0012] The required content of control channel messages is determined by the system deployment and UE configuration. For example, if the infrastructure does not support MIMO, or if the UE is configured in a non-MIMO transmission mode, there is no need to inform it of parameters required only for MIMO transmission. Therefore, to minimize signaling overhead, it is desirable to have several different message formats available, each containing the minimum payload required for a particular scenario. On the other hand, to avoid overcomplicating implementation and testing, it is desirable not to specify too many formats. The set of DCI message formats specified for LTE is listed below.

[0013] Please refer to the above technical standards or Non-Patent Document 5.

[0014] - Format 0 DCI format 0 is used for transmitting resource grants in pushes and uses single-antenna port transmission in uplink transmit mode 1 or 2.

[0015] - Format 1 DCI format 1 is used for transmitting resource allocations for single codeword PDSCH transmissions (downlink transmission modes 1, 2, and 7).

[0016] - Format 1ADCI format 1A is used for compact signaling of resource allocation for single codeword PDSCH transmissions, and for assigning dedicated preamble signatures to mobile terminals for race-free random access (for all transmission modes).

[0017] - Format 1B DCI format 1B is used for compact signaling of resource allocation for PDSCH transmissions that use closed-loop precoding with rank 1 transmissions (downlink transmission mode 6). The transmitted information is the same as in format 1A, but an indicator of the precoding vector applied to PDSCH transmissions is added.

[0018] - Format 1C DCI format 1C is used for very compact transmissions of PDSCH assignments. When format 1C is used, PDSCH transmissions are required to use QPSK modulation. Format 1C is used, for example, to signal call messages and broadcast system information messages.

[0019] - Format 1D DCI format 1D is used for compact signaling of resource allocation for PDSCH transmissions using multi-user MIMO. The transmitted information is the same as in format 1B, except that instead of one of the pre-coding vector indicator bits, there is a single bit indicating whether a power offset is applied to the data symbol. This feature is needed to indicate whether the transmit power is shared between two UEs. Future versions of LTE may extend this feature to cases of power sharing between multiple UEs.

[0020] - Format 2 DCI format 2 is used to transmit resource allocations to PDSCH for closed-loop MIMO operation (transmit mode 4).

[0021] - Format 2A : DCI format 2A is used for transmitting the resource allocation for PDSCH for open-loop MIMO operation. The information transmitted is the same as that of format 2 (transmission mode 3), except that when the eNodeB (the name of the base station in LTE) has two transmit antenna ports, there is no precoding information, and two bits are used for four antenna ports to indicate the transmission rank.

[0022] - Format 2B : Introduced in Release 9, it is used for transmitting the resource allocation for PDSCH for dual-layer beamforming (transmission mode 8).

[0023] - Format 2C : Introduced in Release 10, it is used for transmitting the resource allocation for PDSCH for closed-loop single-user or multi-user MIMO operation using up to 8 layers (transmission mode 9).

[0024] - Format 2D : Introduced in Release 11, it is used up to 8-layer transmission and is mainly used for COMP (Cooperative Multipoint) (transmission mode 10).

[0025] - Formats 3 and 3A : DCI formats 3 and 3A are used for transmitting power control commands for PUCCH and PUSCH using 2-bit or 1-bit power adjustment respectively. These DCI formats include individual power control commands for groups of UEs.

[0026] - Format 4 : DCI format 4 is used for scheduling PUSCH and uses closed-loop spatial multiplexing transmission in uplink transmission mode 2.

[0027] A search space represents a set of CCE locations where a UE can find its PDCCH. Each PDCCH carries one DCI, identified by an RNTI (Radio Network Temporary Identifier) ​​implicitly encoded in the DCI's CRC attachment. The UE monitors the CCEs of the configured search space by blind decoding and CRC checking. A search space can be a common search space and a UE-specific search space. The UE needs to monitor both the common and UE-specific search spaces, which may overlap. The common search space carries DCIs common to all UEs, such as system information (using SI-RNTI), calls (P-RNTI), PRACH responses (RA-RNTI), or UL TPC commands (TPC-PUCCH / PUSCH-RNTI). The UE-specific search space can carry DCIs for UE-specific assignments, using UE assignment C-RNTI, semi-persistent scheduling (SPS C-RNTI), or initial assignment (temporary C-RNTI).

[0028] DCI thus specifies the resources for the UE to receive or send data, including the send / receive configuration. [Prior art documents] [Non-patent literature]

[0029] [Non-Patent Document 1] 3GPP TSG RAN TR 38.913 v14.1.0, “Study on Scenarios and Requirements for Next Generation Access Technologies”, Dec. 2016 [Non-Patent Document 2] 3GPP TSG TR 38.801 v2.0.0, “Study on New Radio Access Technology; Radio Access Architecture and Interfaces”, March 2017 [Non-Patent Document 3] section 11.2.2.2 of S. Sesia, I. Toufik and M, Baker, LTE: The UMTS Long Term Evolution, Second Edition [Non-Patent Document 4] section 8.2 of S. Sesia, I. Toufik and M, Baker, LTE: The UMTS Long Term Evolution, Second Edition [Non-Patent Document 5] LTE - The UMTS Long Term Evolution - From Theory to Practice, Edited by Stefanie Sesia, Issam Toufik, Matthew Baker, Chapter 9.3.5 [Non-Patent Document 6] 3GPP TSG RAN Meeting #75, RP-171485 by NTT DoCoMo, “Revised WID on New Radio Access[] Technology”, June 5-8, 2017 [Non-Patent Document 7] RAN1 NR#3 (RAN1 Chairman Notes: RAN1 NR Ad-Hoc#3) [Non-Patent Document 8] section 29.1.1 of S. Sesia, I. Toufik and M, Baker, LTE: The UMTS Long Term Evolution, Second Edition [Non-Patent Document 9] 3GPP TS 36.212, V14.3.0 (Table 5.3.3.1.5C-2) [Overview of the Initiative]

[0030] In one non-limiting and exemplary embodiment, in a mobile communication system where data is transmitted and / or received within layers using multiple antennas, signaling of co-scheduling information (non-transparent MU-MIMO) is facilitated for each code division multiplexing (CDM) group. More specifically, the disclosure proposes a set of layer-port mapping combinations to be combined with co-scheduling information to facilitate a more efficient and effective signaling mechanism.

[0031] One of the primary aspects of this disclosure is a base station, The circuit and the said circuit are It transmits parameters that define a configuration for assigning each resource to a port for carrying a reference signal, and each resource is grouped into multiple code division multiplexing (CDM) groups. It transmits control information indicating one of a set of layer / port mapping combinations, which is applied to place a reference signal on at least one port of a CDM group for data transmission and / or reception. The control information indicates coordinate scheduling information for at least one CDM group and / or at least one other CDM group among a plurality of CDM groups for the same data transmission and / or reception. A transmitting / receiving unit that controls the transmission and / or reception of data within a layer based on the aforementioned cooperative scheduling information, Equipped with, Each resource assigned to the port includes two resource element configurations: The first resource element configuration includes a comb and a cyclic shift of a reference signal, wherein the comb consists of either a subcarrier having an odd subcarrier index or a subcarrier having an even subcarrier index. The second resource element configuration includes frequency division multiplexing and frequency division quadrature cover code (OCC), The circuit further transmits an indicator to the mobile terminal indicating whether the first resource element configuration is being used or the second resource element configuration is being used. It is a base station.

[0032] Another aspect of this disclosure is a communication system including a mobile terminal and a base station, The aforementioned mobile terminal is The circuit and the said circuit are It receives parameters that define a configuration for assigning each resource to a port for carrying a reference signal, and each resource is grouped into multiple code division multiplexing (CDM) groups. To receive control information indicating one of a set of layer / port mapping combinations, which is applied to place a reference signal on at least one port of a CDM group for data transmission and / or reception. The control information indicates coordinate scheduling information for at least one CDM group and / or at least one other CDM group among a plurality of CDM groups for the same data transmission and / or reception. A transceiver that uses multiple antennas to transmit and / or receive data within a layer, based on the aforementioned coordinate scheduling information, Equipped with, Each resource assigned to the port includes two resource element configurations: The first resource element configuration includes a comb and a cyclic shift of a reference signal, wherein the comb consists of either a subcarrier having an odd subcarrier index or a subcarrier having an even subcarrier index. The second resource element configuration includes frequency division multiplexing and frequency division quadrature cover code (OCC), The circuit further receives an indicator from the base station indicating whether the first resource element configuration is being used or the second resource element configuration is being used. The aforementioned base station is The base station circuit and the said base station circuit are Send parameters that define a configuration for assigning each resource to a port for carrying the aforementioned reference signal, It transmits control information indicating one of the sets of layer / port mapping combinations. Based on the aforementioned coordinate scheduling information, a base station transceiver uses multiple antennas to transmit and / or receive data within the layer, Equipped with, The base station circuit is a communication system that further transmits the indicator to the mobile terminal.

[0033] In one embodiment, the technique disclosed herein features a mobile terminal comprising: a circuit that receives parameters defining a configuration for assigning each resource, grouped into a plurality of code division multiplexing (CDM) groups, to a port for carrying a reference signal, and a circuit that receives control information indicating one of a set of layer / port mapping combinations applied to position the reference signal at a port in at least one CDM group for transmitting and / or receiving data, wherein the control information indicates coordinating scheduling information for the at least one CDM group and / or at least one other CDM group among a plurality of CDM groups for the same data transmission and / or reception; and a transceiver that transmits and / or receives data in a layer using a plurality of antennas based on the coordinating scheduling information.

[0034] It should be noted that general or specific embodiments can be implemented as systems, methods, integrated circuits, computer programs, storage media, or a selective combination thereof.

[0035] Further benefits and advantages of the disclosed embodiments will become apparent from this specification and the drawings. These benefits and / or advantages can be obtained individually by the various embodiments and features of this specification and the drawings, but not all of these embodiments and features are necessary to obtain one or more of such benefits and / or advantages. [Brief explanation of the drawing]

[0036] [Figure 1-1] Figures 1A and 1B are schematic diagrams of the configuration types of front-loaded demodulation reference signals (DMRS). [Figure 1-2] Figures 1C and 1D are schematic diagrams of the configuration types of the forward demodulation reference signal (DMRS). [Figure 2] This is a block diagram showing the configuration of mobile terminals and base stations. [Figure 3] This figure shows an exemplary set of layer / port mapping combinations, combined with coordinating scheduling information, for each CDM group for DMRS configuration type 1 and 1-symbol DMRS configurations. [Figure 4] This figure shows an exemplary set of layer / port mapping combinations, combined with coordinating scheduling information, for each CDM group for DMRS configuration types 1 and 2 symbol DMRS configurations. [Figure 5] This figure shows an exemplary set of layer / port mapping combinations, combined with coordinating scheduling information, for each CDM group in the case of DMRS configuration type 2 and for a single-symbol DMRS. [Figure 6A]This figure shows an exemplary set of layer / port mapping combinations, combined with coordinating scheduling information, for each CDM group in the case of DMRS configuration type 2 and for 2-symbol DMRS. [Figure 6B] This figure shows an exemplary set of layer / port mapping combinations, combined with coordinating scheduling information, for each CDM group in the case of DMRS configuration type 2 and for 2-symbol DMRS. [Modes for carrying out the invention]

[0037] In the 3rd Generation Partnership Project New Radio (3GPP NR), the reference signal has been redesigned to accommodate a wide range of requirements and use cases. The demodulated reference signal (DMRS) used for channel estimation purposes is also designed to have a uniform structure in both uplink and downlink using cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) waveforms. This disclosure relates to signaling configurations for supporting non-transparent multi-user multiple-input multiple-output (MU-MIMO). Two configurations of forward DMRS (with different multiplexing schemes for orthogonal DMRS ports) are supported, each with the adaptability to use one-symbol or two-symbol DMRS.

[0038] In current LTE systems, orthogonal DMRS ports have a fixed configuration based on a single category of multiplexing scheme, and do not support non-transparent MU-MIMO.

[0039] However, in 3GPP NR, the situation is more complex due to the potential for increased interference from co-scheduled DMRS ports to other UEs. In addition, frequency division multiplexing (FDM) between different DMRS ports necessitates rate matching. This makes it desirable for NR to support UE-intransparent MU-MIMO. This disclosure provides a framework for showing at least some information about co-scheduled DMRS ports within the same and / or different CDM groups in MU-MIMO by adding a new field to the DMRS layer and port mapping table.

[0040] This disclosure relates to NR technology. For NR access technology, see Non-Patent Document 6. More specifically, NR access technology deals with both downlink and uplink forward DMRS configurations using CP-OFDM waveforms. Non-Patent Document 7 incorporates DMRS, thereby providing a framework for signaling at least some information related to co-scheduled DMRS ports by using a mapping table of DMRS layers and ports.

[0041] As described above, in 3GPP NR, the demodulation reference signal (DMRS) has been redesigned for both downlink and uplink.

[0042] The two configurations shown in Figures 1A-1D are supported for forward DMRS in the downlink and uplink using CP-OFDM waveforms.

[0043] As shown in the diagram, when a single-symbol DMRS is used, the forward reference signal is assigned to the resource of the first data symbol adjacent to the resource of the TTI signaling section (for example, a signaling section consisting of two symbols), and when a two-symbol DMRS is used, it is assigned to the resources of the first two data symbols.

[0044] Figures 1A and 1B show exemplary resource grids corresponding to slots consisting of 14 symbols and 12 subcarriers, respectively. The first two symbols on the left side of each figure correspond to the signaling section of the slot. The physical downlink control channel (PDCCH) is communicated in the signaling section. In LTE, this exemplary resource grid corresponds to one of the two slots in a subframe. However, this does not limit the disclosure, for a subframe may correspond to a (single) slot, or it may contain three or more slots, and a slot may have more or fewer than 14 symbols and more or fewer than 12 subcarriers.

[0045] A first forward DMRS configuration corresponding to configuration type 1 is shown in Figures 1A and 1B. This configuration is intended to support up to eight orthogonal DMRS ports for single-user multiple-input multiple-output (SU-MIMO) or multi-user multiple-input multiple-output (MU-MIMO). The first configuration supports up to four orthogonal DMRS ports when a single-symbol DMRS is used, as shown in Figure 1A. In particular, up to four component sets can be formed by combining two combs and two cyclic shifts (CSs), and each resulting component set can be assigned to up to four DMRS ports. These component sets are also represented as CDM groups in the context of this disclosure.

[0046] As shown in Figure 1B, when two-symbol DMRS is used, two combs and two cyclic shifts can be combined with two time-division orthogonal cover codes (TD-OCCs), particularly with the Walsh-Hadamard TD-OCC ({1,1} and {1,-1}), supporting up to eight orthogonal DMRS ports. However, with two-symbol DMRS, it should also be possible to schedule up to four DMRS ports without using {1,1} and {1,-1}.

[0047] A second forward DMRS configuration corresponding to configuration type 2 is shown in Figures 1C and 1D. This configuration provides support for up to 12 orthogonal ports for SU-MIMO or MU-MIMO. Specifically, two (Walsh-Hadamard) frequency-division orthogonal cover codes (FD-OCCs), each applied across adjacent resource elements (REs) in the frequency domain, generate six component sets, or CDM groups.

[0048] As can be seen from Figures 1C and 1D, with 12 subcarriers, pairs of adjacent REs are grouped into three frequency division multiplexing (FDM) groups. Thus, six component sets are obtained from two FD-OCCs (both {1,1} and {1,-1}) applied to each of the three FDM groups. In the case of a one-symbol DMRS (Figure 1C), each of the six resulting component sets can be assigned to up to six orthogonal DMRS ports. In the case of a two-symbol DMRS, these six component sets can be combined with two more TD-OCCs to obtain the ability to support up to 12 orthogonal DMRS ports (Figure 1D).

[0049] As described above with reference to Figures 1A-1D, the comb, cyclic shift, FD-OCC, FDMs, and TD-OCC constitute resource elements for the reference signal, particularly for the forward DMRS.

[0050] These resource elements are combined according to the first or second forward DMRS configuration, and the resulting set of components or CDM groups are each assigned to an orthogonal DMRS port. However, the use of two-symbol DMRS should also be possible at lower ranks. Not all of the set of components or CDM groups supported by a particular configuration in the case of one-symbol or two-symbol DMRS need to be used for port assignment. In particular, even in the case of two symbols, it should be possible to schedule six DMRS ports without using both {1,1} and {1,-1}.

[0051] From the user equipment (UE) perspective, DMRS ports multiplexed by frequency domain code division multiplexing (CDM) are located in roughly the same place.

[0052] Further consideration is still needed regarding whether the forward DMRS configuration type of the UE may differ between UL and DL. Furthermore, if the above agreement involves significant complexity / performance issues, down-selection may still be discussed.

[0053] LTE DMRS configuration

[0054] The DMRS configuration in 3GPP NR described above differs from that of LTE, which primarily has a single downlink configuration supporting up to eight orthogonal ports / layers in total, using frequency and time code division multiplexing with Walsh-Hadamard orthogonal cover codes. The configuration and further details of the DMRS configuration in LTE can be found in Non-Patent Document 8.

[0055] Table 1 below shows the current LTE layer and port mapping, taken from Non-Patent Document 9.

[0056] [Table 1]

[0057] LTE supports up to eight orthogonal DMRS ports for downlink, primarily using a single category of multiplexing scheme (Time / Frequency OCC). Therefore, any port combination can be used to map layers without affecting the operation of a given scenario. Furthermore, the use of resources (DMRS overhead) for a given number of layers is the same for any port combination.

[0058] Furthermore, LTE provides limited support for MU-MIMO. Fixed DMRS configurations are also supported, and therefore, additional signaling is not required for dynamic configurations.

[0059] As can be seen from Table 1, the number of possible combinations of layer-port mappings in LTE is very limited. A bitmap of length 4 is defined to inform a given user of the layer-port mapping. The minimum number of port combinations is supported for the layer-port mapping results subject to the following limitations: For up to two layers, the port indexing of the mapping is contiguous and non-overlapping. For three to eight layers, the indexing is contiguous, non-overlapping, and starts from index 0 as a fixed starting point. The mapping is limited to one port combination.

[0060] The latest LTE release supports only transparent MU-MIMO (and not opaque MU-MIMO). However, this is not always the case.

[0061] In LTE Rel-8, when MU-MIMO was first introduced to support transmission to up to two UEs, non-transparent MU-MIMO was introduced by dedicating one bit to a dedicated power offset field. Nevertheless, support for non-transparent MU-MIMO for three or more UEs was never agreed upon, and not in more recent LTE releases. It was determined that the disadvantage of increased signaling overhead did not outweigh the advantages gained as a result of the increase.

[0062] DMRS requirements for NR

[0063] The limitations on LTE layer and port mapping are no longer acceptable for 3GPP NR. In particular, there is a demand for non-transparent MU-MIMO to benefit from the advantages of new system designs in 3GPP NR.

[0064] For example, in order to incorporate non-transparent MU-MIMO support into 3GPP NR, the decision made for LTE, which does not have a dedicated bit field, could be reconsidered. However, for now, a dedicated bit field for MU-MIMO exists, so support is not necessary.

[0065] The embodiments will be described.

[0066] This disclosure facilitates the signaling of coordinating scheduling information (non-transparent MU-MIMO) for each code division multiplexing (CDM) group in a mobile communication system where data is transmitted and / or received within layers using multiple antennas. More specifically, this disclosure proposes a set of combined layer-port mapping information to be combined with coordinating scheduling information to facilitate a more efficient and effective signaling mechanism.

[0067] In an exemplary embodiment shown in Figure 2, the disclosure presents a mobile terminal 210 that transmits and / or receives data to and from a base station 260 that uses multiple antennas in a mobile communication system. The mobile terminal 210 and the base station 260 are configured to transmit and / or receive data via a radio channel 250.

[0068] The mobile terminal 210 can support what is commonly called a user device (UE) in LTE and NR, and the base station 260 can support what is called an advanced NodeB (eNodeB or eNB) or next-generation NodeB (gNode or BgNB) in LTE and NR.

[0069] More specifically, the mobile terminal 210 is configured to transmit and / or receive data to and from the base station 260 within a layer. As discussed above, the term layer (or spatial layer) refers to one of several streams that are generated by spatial multiplexing and then exchanged between the mobile terminal 210 and the base station 260 via separate antenna ports.

[0070] For coherent demodulation of the transmitted and (subsequently) received data, a reference signal is also exchanged between the mobile terminal 210 and the base station 260. As discussed above, the transmission and / or reception of the reference signal is performed by referring to a layer-port mapping. This mapping specifies, for each layer, one DMRS port to be used to transmit / receive the reference signal.

[0071] In particular, the layer-to-port mapping varies depending on the configuration of the base station 260 and the mobile terminal 210, that is, depending on the configuration specified by the DMRS configuration type (e.g., DMRS configuration type 1 or 2) and the number of symbols to be used for DMRS (e.g., 1-symbol or 2-symbol DMRS). As discussed above, this configuration not only determines the resources for carrying DMRS but also the maximum number of DMRS ports that can be scheduled by the base station 260.

[0072] In other words, the mobile terminal 210 and base station 260 return to different layer and port mappings depending on which of several configurations is selected for communication in the mobile communication system. The DMRS port configuration specifies that base station 260 and the mobile terminal can use the layer and port mapping to perform data transmission and / or reception.

[0073] For this purpose, the mobile terminal 210 includes, for example, a transceiver 220 and a processor 230, which, when operating, receive parameters that define a configuration that assigns each (time-frequency) resource carrying a reference signal to a DMRS port. In other words, this configuration assigns each of the reference signals from one or more DMRS ports to a specific resource, which may also be represented as a set of (resource) elements.

[0074] Resources or resource element sets are grouped into multiple sign division multiplexing (CDM) groups. Specifically, each CDM group specifies, by each resource or resource element set, a resource or resource element set for each DMRS port to carry the maximum number of quadrature reference signals, for example, two or four, that can be carried by each DMRS port in the same CDM group.

[0075] Referring to the example shown in Figure 1A, the resources of two combs (comb1, comb2), each having two cyclic shifts (which constitute two different sets of DMRS ports), define separate CDM groups (CDM group 0, CDM group 1). In the example shown in Figure 1B, the resources of two combs (comb1, comb2), each having two cyclic shifts and two TD-OCCs (which constitute four different sets of DMRS ports), define separate CDM groups (CDM group 0, CDM group 1).

[0076] Furthermore, in the example shown in Figure 1C, the resources of three FDM groups (FDM1, FDM2, FDM3), each having two FD-OCCs (which constitute two different sets of DMRS ports), define separate CDM groups (CDM group 0, CDM group 1, CDM group 2). Finally, in the example shown in Figure 1D, the resources of three FDM groups (FDM1, FDM2, FDM3), each having two FD-OCCs and two TD-OCCs (which constitute four different sets of DMRS ports), define separate CDM groups (CDM group 0, CDM group 1, CDM group 2).

[0077] As already mentioned above, the (time-frequency) resources for carrying the reference signal are grouped into multiple code division multiplexing (CDM) groups. In particular, in the context of this disclosure, a CDM group refers to a set of DMRS ports that use the same resources and are orthogonal to each other by using orthogonal cover codes (OCD) or time and / or frequency code division multiplexing (CDM).

[0078] In the context of this disclosure, a CDM group is referred to from the perspective of the mobile terminal 210. On the mobile terminal 210, a CDM group refers to a set of DMRS port resources or (resource) elements located in approximately the same location.

[0079] Again, in an exemplary embodiment, the circuitry of the mobile terminal 210, which is, for example, a transceiver 220 and a processor 230, receives control information during operation that indicates one of a set of layer-to-port mapping combinations, which is applied to place a reference signal on the DMRS port of at least one CDM group for transmitting and / or receiving data.

[0080] Next, the mobile station 210 uses one of the indicated sets of layer-port mapping combinations to determine the DMRS port and, based on the configuration of the resource or (resource) element set, determines the respective resources for transmitting and / or receiving data for this DMRS port. In other words, only in combination do the configuration and indicated layer-port mapping enable the transmission and / or reception of data.

[0081] However, both configuration parameters and control information are not received simultaneously by the mobile terminal 210. Rather, the base station 260 can only inform the base station of configuration parameters, for example, through the Radio Resource Control (RRC) protocol, while control information can be communicated via the Physical Downlink Control Channel (PDCCH) along with scheduling information in the Downlink Control Information (DCI).

[0082] Furthermore, for exemplary embodiments, the received control information is not limited to showing the mobile terminal 210 one of a set of layer and port mapping configurations. Rather, the received control information further shows the mobile terminal 210 cooperative scheduling information for each CDM group.

[0083] This coordinated scheduling information can then be used for transmitting and / or receiving the same data, i.e., to improve interference cancellation and / or rate matching for transmitting and / or receiving data of the same TTI.

[0084] Providing co-scheduling information for each CDM group results in favorable trade-offs for non-transparent MU-MIMO signaling. In particular, providing co-scheduling for each CDM group offers the advantage of minimizing signaling overhead in terms of improving interference cancellation and / or adapting rate matching to increase data transmission capacity.

[0085] In the following, a distinction is made between the indication of cooperative scheduling information for CDM groups (referred to hereafter as the first set of CDM groups) to which the mobile terminal 210 is scheduled to transmit and / or receive reference signals, and for other CDM groups (referred to as the second set of CDM groups) to which the mobile terminal 210 is not scheduled. However, this distinction becomes even clearer when considering the benefits that can be obtained by cooperative scheduling information.

[0086] As described above, the mobile terminal 210 can use cooperative scheduling indicators to improve interference cancellation.

[0087] Within each CDM group, base stations coordinate scheduling different mobile terminals to assign reference signals to the same resource DMRS ports (within the same CDM group). Although DMRS ports are said to be orthogonal to each other within a CDM group, leakage can occur between reference signals, potentially degrading the reception quality of the reference signals. Consequently, this interference reduces the coherent demodulation capability of data transmission and / or reception.

[0088] Here, additional coordinating scheduling information based on the CDM group allows the mobile station to know the coordinating schedule of the CDM group, i.e., the resources, that are also carrying its own reference signal. In other words, this additional coordinating scheduling information allows the mobile station to perform interference cancellation on the reference signal, thereby improving its coherent demodulation capability.

[0089] Notably, the improvement in interference cancellation is related to the coordinated scheduling information within the CDM group, where the mobile terminal 210 is scheduled to perform the transmission and / or reception of the reference signal (the first set of CDM groups).

[0090] Furthermore, the mobile terminal 210 can use cooperative scheduling indicators to improve rate matching.

[0091] Within each CDM group, the base station can schedule separate mobile terminals to assign reference signals to separate DMRS ports of different resources (for example, in separate CDM groups). While scheduling DMRS ports for separate CDM groups is optimal for the interference characteristics of the CDM group, this scheduling prevents mobile terminals from reusing different resources (from the same context) for transmitting and / or receiving data.

[0092] In other words, information about the (actual) allocation of reference signals to separate resources (in separate CDM groups) places the mobile terminal in a position where it can decide to assign symbols to carry data transmission and / or reception to these (additional) separate resources (in separate CDM groups). This increases the data transmission capacity in each TTI, and therefore, it goes without saying that adaptive rate matching is needed to take advantage of the increased data transmission capacity.

[0093] Here, additional coordinating scheduling information based on the CDM group allows the mobile station to know the coordinating scheduling of other CDM groups, i.e., resources, that do not carry its own reference signal. That is, this additional coordinating scheduling information allows the mobile terminal to then decide whether to reuse these resources from separate CDM groups for data transmission and / or reception, but this reuse requires rate matching adapted to the increase in data transmission capacity.

[0094] Notably, the improved rate matching for transmitting and / or receiving the same TTI data is only related to coordinate scheduling information in separate CDM groups (a second set of CDM groups) where the mobile terminal is not scheduled to perform the transmission and / or reception of the reference signal.

[0095] In short, the benefits of improved interference cancellation and the adaptation of rate matching to increase data transmission capacity are both tied to the existence of co-scheduling information for each CDM group, but depend on whether co-scheduling is indicated for CDM groups that are scheduled to perform reference signal transmissions (first set of CDM groups) or not (second set of CDM groups).

[0096] Therefore, it is already clear from this disclosure that disclosing co-scheduling information has a favorable effect, even if the information is only known for a subset of multiple CDM groups and not for all of them.

[0097] In the context of this disclosure, the co-scheduling information is provided for each CDM group. This co-scheduling information should be understood as indicating to a mobile terminal that the base station is co-scheduling another mobile terminal to the DMRS port of each resource in the CDM group for the transmission and / or reception of a reference signal.

[0098] Depending on the CDM group providing the collaborative scheduling information, it may be advantageous to interpret the collaborative scheduling information separately.

[0099] For the second set of CDM groups, the cooperative scheduling information allows mobile terminals to adapt rate matching so that they benefit from increased data transmission capacity. Notably, all a mobile terminal needs to know to do this is whether (or not) there is at least one other mobile terminal assigned to a DMRS port in another CDM group.

[0100] If one of the second sets of CDM groups has at least one assigned DMRS port, then the transmission and / or reception of each reference signal is considered more important than the benefits of rate matching adaptation and increased data transmission capacity. Otherwise, the mobile terminal can adapt rate matching to take advantage of its increased data transmission capacity.

[0101] Therefore, for a second set of CDM groups, the cooperative scheduling information can thus be interpreted as indicating "at least one" different mobile terminal that is scheduled for each CDM group.

[0102] For the first set of CDM groups, the cooperative scheduling information allows mobile terminals to benefit from improved interference cancellation. However, this improved interference cancellation is only necessary when there are more than a given number (represented as number X in Figures 3-6), for example, more than one (e.g., two or three), of mobile terminals to which separate DMRS ports of the same CDM group in the first set are assigned.

[0103] Rather, if there are fewer than a given number of mobile terminals assigned separate DMRS ports to the same CDM group in the first set, for example, one or none, then it can be reasonably expected that the existing mechanism is functioning well enough to establish orthogonal DMRS ports.

[0104] For example, in a 3GPP NR deployment scenario, interference cancellation is improved by utilizing a blind interference detection mechanism at the reference signal receiver. This improves the receiving characteristics of the reference signal even without any prior knowledge of interference at the receiver (only co-scheduling information indicates that there is interference from a given number of mobile terminals, e.g., two or three).

[0105] However, blind interference detection mechanisms are computationally complex, costly in terms of power consumption, and introduce a non-negligible processing delay into the signaling flow, making them advantageous only when many interferences are (actually) indicated. For this purpose, the number of co-scheduling interferences shown in the first set of CDM groups (represented as number X in Figures 3-6) is different from the number of co-scheduling interferences shown in the second set of CDM groups.

[0106] In other words, the interpretation of the co-scheduling information can depend on the CDM group, and therefore on the set of CDM groups from which the co-scheduling information is received. If the co-scheduling information is received for a first set of CDM groups from which its own reference signal is carried, the co-scheduling information may indicate the presence of a given number of co-scheduled mobile terminals per CDM group compared with a second set of CDM groups, in which case the co-scheduling information may indicate the presence of any co-scheduled mobile terminals per CDM group.

[0107] Similarly, this disclosure also presents a base station 260 for transmitting and / or receiving data to and from a mobile terminal 210 using multiple antennas in a mobile communication system. Again, the base station 260 and the mobile terminal 210 are configured to transmit and / or receive data via a radio channel 250.

[0108] The base station 260 includes, for example, a transceiver 270 and a processor 280, which, when in operation, transmits parameters to the mobile terminal 210 that define a configuration that assigns each resource, grouped into multiple code division multiplexing (CDM) groups, to a port for carrying a reference signal, and transmits control information to the mobile terminal 210 that indicates one of a set of layer-port mapping combinations that are applied to place the reference signal on a port in at least one CDM group for transmitting and / or receiving data.

[0109] In addition, the control information also includes coordinate scheduling information for at least one CDM group and / or at least one other CDM group among multiple CDM groups for the same data transmission and / or reception.

[0110] Here, we refer to the form in which control information is transmitted between the base station 260 and the mobile station 210. For this purpose, we refer to Figures 3-6 as exemplary embodiments of the signaling mechanism.

[0111] As discussed earlier, the control information (column 1 in each figure) not only shows the mobile terminal 210 one of the sets of layer and port mapping configurations (columns 2 and 3 in each figure), but also provides coordinate scheduling information (columns 4 and 5 or 4-6 in each figure) for each CDM group, as shown to the mobile terminal 210.

[0112] In this regard, for example, a mobile terminal 210 that receives control information in binary format refers to the row with the corresponding index (in column 1 of each figure), and thus obtains the layer-to-port mapping indicated by the base station, as well as the co-scheduling information for each of the CDM groups. As can be seen from the figure, it has been proposed to provide the control information with separate (multiple) rows with the same port-to-layer mapping to reflect all possible permutations of the co-scheduling information.

[0113] More specifically, Figure 3 shows an exemplary set of layer-port mapping combinations (columns 2 and 3) combined with coordinating scheduling information (columns 4 and 5) for each CDM group for DMRS configuration type 1 and a 1-symbol DMRS configuration. Thus, this example is based on assigning DMRS ports to the resources shown in Figure 1A, allowing a total of two DMRS ports to be scheduled for each of the two CDM groups.

[0114] Similarly, Figure 4 shows an exemplary set of layer-port mapping combinations (columns 2 and 3) combined with coordinating scheduling information (columns 4 and 5) for each CDM group for DMRS configuration types 1 and 2 symbol DMRS configurations. Thus, this example is based on assigning DMRS ports to the resources shown in Figure 1B, and a total of four DMRS ports can be assigned to each of the two CDM groups.

[0115] Furthermore, Figure 5 shows an exemplary set of layer-port mapping combinations (columns 2 and 3) for each CDM group, combined with coordinating scheduling information (columns 4-6), for DMRS configuration type 2 and 1 symbol DMRS. Thus, this example is based on allocating DMRS ports to the resources shown in Figure 1C, and a total of two DMRS ports can be allocated to each of the three CDM groups.

[0116] Furthermore, Figures 6A and 6B show exemplary sets of layer-port mapping combinations (columns 2 and 3) combined with coordinating scheduling information (columns 4-6) for each CDM group in the case of DMRS configuration type 2 and 2-symbol DMRS. Thus, this example is based on assigning DMRS ports to the resources shown in Figure 1D, allowing a total of four DMRS ports to be scheduled for each of the three CDM groups.

[0117] In all exemplary embodiments shown in Figures 3-6, it is assumed that the CDM groups and DMRS ports are indexed as follows:

[0118] 1. CDM groups are assigned consecutive indexes, and the DMRS ports of CDM groups are also assigned consecutive indexes, meaning that the index of a DMRS port increases along with the indexes of multiple CDM groups.

[0119] In other words, when considering a (single) CDM group, the indices of the DMRS ports in this CDM group are distributed contiguously. This can already be inferred from the fact that each DMRS port in a CDM group is assigned a contiguous index, regardless of the specific CDM group.

[0120] Now, considering another CDM group, the DMRS port indices are distributed within the CDM group such that one DMRS port in a particular CDM group with a small index has a smaller index than one DMRS port in another particular CDM group with a larger index.

[0121] Since we have defined a sequential indexing of CDM groups and DMRS ports, in the exemplary embodiments shown in Figures 3-6, it is also assumed that the base station assigns DMRS ports to mobile stations sequentially and incrementally (i.e., sequentially) for all of the multiple CDM groups.

[0122] 2. Mobile terminals are assigned a DMRS port from among all CDM groups, which have consecutive indices starting with the DMRS port with the lowest index.

[0123] For the sake of discussion, let us assume that base station 260 assigns the mobile terminal 210 the DMRS port with the lowest index (DMRS port 0, i.e., P0). In this case, if base station 260 wants to assign another DMRS port to the same mobile terminal 210, the base station must proceed to assign the next DMRS port with a larger consecutive index (DMRS port 1, i.e., P1). Therefore, it is not possible for a single mobile terminal to be assigned two DMRS ports that do not have consecutive indices.

[0124] Reducing the total number of rows that can be indexed as control information reduces the total signaling overhead in the control signals. In particular, the inventors have found that signaling of control information can be most efficient and effective when the following rules are followed.

[0125] 3. In MU-MIMO, the maximum number of DMRS ports that can be scheduled per mobile terminal is limited to a given number, which is less than the maximum number of DMRS ports defined, for example, by the configuration for allocating resources to each port.

[0126] On the other hand, by reducing the maximum number of DMRS ports per mobile terminal in MU-MIMO, the total number of permutations reflected in the control information, which indicates coordinated scheduling for each layer-port mapping and CDM group, is drastically reduced.

[0127] On the other hand, if the control information indicates an unusual number of DMRS ports (greater than the maximum number of DMRS ports in MU-MIMO) in relation to the layer-port mapping, then the mobile terminal can be considered to be operating in SU-MIMO for data transmission and / or reception.

[0128] In the latter case, the mere fact that SU-MIMO is configured does not necessitate additional co-scheduling information being shown for any of the CDM groups. In line with this, the control information then indicates, for example, that there is no co-scheduling.

[0129] For example, this is shown in Figure 3 for the control information corresponding to index 11 (control information = "1011") and the control information corresponding to index 12 (control information = "1100"). The figure shows three DMRS ports (ports P0-P2) or four DMRS ports (ports P0-P4), even though the maximum number of DMRS ports per mobile terminal in MU-MIMO is two. Therefore, it can be seen that data transmission and / or reception is performed in SU-MIMO on the mobile terminal. In other words, there is no cooperative scheduling, and therefore the cooperative scheduling information is "0" for CDM group 0 and "0" for CDM group 1.

[0130] 4. In SU-MIMO, the maximum number of DMRS ports that can be scheduled for each mobile terminal is limited to a given number, which is less than the maximum number of DMRS ports defined, for example, by the configuration for allocating resources to each port.

[0131] In SU-MIMO, reducing the maximum number of DMRS ports per mobile terminal further reduces the total number of permutations reflected in the control information that indicate coordinated scheduling for each layer-port mapping and CDM group.

[0132] For example, this is shown in Figure 5, where despite the availability of a total of eight DMRS ports (ports P0-P7), the control information index ends at number 22 (control information = "10110"), which is associated with "only" four ports (ports P0-P3) operating in SU-MIMO.

[0133] Note that there are no SU-MIMO operating modes that can be configured in Figures 4 and 6A / B. This is because the maximum number of ports per mobile terminal is the same for both MU-MIMO and SU-MIMO, and therefore MU-MIMO is given priority in displaying cooperative scheduling information.

[0134] 5. Mobile devices to which all DMRS ports of a (single) CDM group are assigned do not expect coordinated scheduling within the same CDM group.

[0135] This also reduces the number of permutations reflected in the control information that indicate coordinated scheduling for each layer-to-port mapping and CDM group.

[0136] For example, this is shown in Figure 3, where the control information corresponding to index 8 (control information "1000") and the control information corresponding to index 9 (control information "1001") are assigned to the mobile terminal itself, and as a result, nothing other than the cooperative scheduling information "0" is shown for this CDM group 0.

[0137] 6. Mobile terminals that are not assigned a DMRS port with the lowest index in a (single) CDM group will expect coordinated scheduling within the same CDM group and within CDM groups with lower indices.

[0138] This signaling of coordinated scheduling information to the CDM group takes advantage of the fact that DMRS ports are allocated sequentially and incrementally (as discussed in number 2 above).

[0139] For the sake of discussion, let us assume that base station 260 assigns mobile terminal 210 a DMRS port with an intermediate index (DMRS port 1, i.e., P1) rather than a DMRS port with the lowest index (DMRS port 0, i.e., P0). In this case, since base station 260 is requested to assign a DMRS port starting from the lowest index, mobile terminal 210 can infer that another co-scheduled mobile terminal is in the same CDM group to which the assigned DMRS port with index 1 belongs. Therefore, it is natural that the co-scheduling information indicated by the control information in MU-MIMO is always "1" within the same CDM group.

[0140] For example, as shown in Figure 3, the cooperative scheduling information shown for the control information corresponding to index 3 (control information = "0011") and index 4 (control information = "0100") is always "1" within CDM group 0. Therefore, this rule also reduces the total number of permutations.

[0141] This inherent signaling of collaborative scheduling information applies not only to the CDM group to which the assigned DMRS port belongs, but also to CDM groups with lower indices.

[0142] For the sake of discussion, let us assume that base station 260 assigns mobile terminal 210 a DMRS port with an intermediate index (DMRS port 3, i.e., P3) rather than a DMRS port with the lowest index (DMRS port 0, i.e., P0). In this case, since base station 260 is requested to assign a DMRS port starting from the lowest index, mobile terminal 210 can infer that the co-scheduled (other) mobile terminal is in the same CDM group 1 to which the assigned DMRS port with index 3 belongs, and also in CDM group 0. Therefore, in MU-MIMO, the co-scheduling information indicated for CDM group 0 and CDM group 1 by the control information is always "1".

[0143] For example, as shown in Figure 3, for the control information corresponding to index 7 (control information = "0111"), the corresponding cooperative scheduling information is always "1" within CDM group 0 and CDM group 1. Therefore, this rule also reduces the total number of permutations.

[0144] This disclosure can be implemented by software, hardware, or software combined with hardware. Each functional block used in the description of each embodiment above can be implemented in part or in whole by an LSI, such as an integrated circuit, and each process described in each embodiment can be controlled in part or in whole by the same LSI or by a combination of multiple LSIs. LSIs can be formed individually as chips, or one chip may be formed to include some or all of the functional blocks. An LSI may include data input / output units coupled thereto. In this specification, LSIs may be referred to as ICs, system LSIs, super LSIs, or ultra LSIs, depending on their level of integration.

[0145] However, the techniques for implementing integrated circuits are not limited to LSIs and may be implemented using dedicated circuits, general-purpose processors, or purpose-specific processors. In addition, FPGAs (Field-Programmable Gate Arrays) that can be programmed after the manufacture of the LSI, or reconfigurable processors that can reconfigure the connections and settings of circuits located inside the LSI, can also be used. This disclosure can be implemented as digital or analog processing. If future circuit technology replaces LSIs as a result of advances in semiconductor technology or other derivative technologies, the functional blocks may also be integrated using that future integrated circuit technology. Biotechnology can also be applied.

[0146] According to a first aspect, a mobile terminal is proposed for transmitting and / or receiving data in layers to and from a base station using multiple antennas in a mobile communication system, the mobile terminal comprising: a circuit that, when in operation, receives from a base station parameters defining a configuration that assigns each resource, grouped into multiple code division multiplexing (CDM) groups, to a port for carrying a reference signal; and a control information from a base station indicating one of a set of layer-to-port mapping combinations that is applied to position the reference signal at a port in at least one CDM group for transmitting and / or receiving data, the control information additionally indicating coordinate scheduling information for the at least one CDM group and / or at least one other CDM group among the multiple CDM groups for the same data transmission and / or reception.

[0147] According to a second embodiment which can be combined with the first embodiment, the control information represents coordinate scheduling information for all or a subset of a plurality of CDM groups.

[0148] According to a third embodiment which can be combined with the first or second embodiment, the co-scheduling information indicates that the base station is co-scheduling different mobile terminals within the at least one and / or another CDM group.

[0149] According to a fourth embodiment which can be combined with the first or second embodiment, the co-scheduling information indicates that the base station is co-scheduling at least several different mobile terminals within the at least one and / or another CDM group.

[0150] According to a fifth embodiment which can be combined with the first to fourth embodiments, the cooperative scheduling information is binary information indicating whether or not cooperative scheduling is present in each of the plurality of CDM groups.

[0151] According to a sixth embodiment which can be combined with the first to fifth embodiments, the plurality of CDM groups are assigned consecutive indices, and each port of the plurality of CDM groups is assigned a consecutive index such that the index of the port increases together with the index of the plurality of CDM groups.

[0152] According to a seventh embodiment which can be combined with the first to sixth embodiments, the cooperative scheduling information indicates cooperative scheduling only for CDM groups among the plurality of CDM groups that have an index equal to or greater than the index of at least one of the CDM groups.

[0153] According to an eighth embodiment which can be combined with the first to seventh embodiments, resources assigned to ports in a CDM group having an index smaller than the minimum index of the port shown in the control information for arranging the reference signal are known to be coordinately scheduled by the base station.

[0154] According to a ninth embodiment which can be combined with the first to eighth embodiments, the mapping means indexing the combination of layer and port mappings and the co-scheduling information.

[0155] According to a tenth embodiment which can be combined with the first to ninth embodiments, the resources assigned to the port include two resource element configurations, the first resource element configuration including a comb and a cyclic shift of a reference signal, the comb consisting of either a subcarrier having an odd subcarrier index or a subcarrier having an even subcarrier index, the second resource element configuration including frequency division multiplexing and frequency division orthogonal cover code (OCC), and the circuit further receives an indicator from the base station during operation indicating whether the first resource element configuration or the second resource element configuration is being used.

[0156] According to an eleventh embodiment which can be combined with the first to tenth embodiments, the parameters defining a configuration that assigns each resource to a port for carrying a reference signal are received via a radio resource control (RRC) protocol.

[0157] According to a twelfth embodiment which can be combined with the first to eleventh embodiments, the control information, which indicates one of the sets of layer-port mapping combinations and the co-scheduling information, is received via a physical downlink control channel (PDCCH).

[0158] According to a thirteenth embodiment that can be combined with the first to twelfth embodiments, the reference signal is a forward demodulation reference signal.

[0159] According to a 14th embodiment which can be combined with the 1st to 13th embodiments, the mobile terminal further comprises a transceiver that performs the data transmission and / or reception in operation by applying the combination of layer and port mappings shown above.

[0160] According to a 15th embodiment which can be combined with the 1st to 14th embodiments, the mobile terminal further comprises a processor that performs interference compensation for the received reference signal and / or rate matching for the data transmission and / or reception during operation.

[0161] According to the 16th aspect, a method is proposed to be performed by a mobile terminal to transmit and / or receive data in layers to and from a base station using multiple antennas in a mobile communication system, the method comprising: receiving from a base station parameters defining a configuration that assigns each resource, grouped into multiple code division multiplexing (CDM) groups, to a port for carrying a reference signal; and receiving from a base station control information indicating one of a set of layer-to-port mapping combinations to be applied to position the reference signal at a port in at least one CDM group for data transmission and / or reception, wherein the control information additionally indicates coordinate scheduling information for the at least one CDM group and / or at least one other CDM group among the multiple CDM groups for the same data transmission and / or reception.

[0162] According to a 17th embodiment which can be combined with the 16th embodiment, the control information represents coordinate scheduling information for all or a subset of the plurality of CDM groups.

[0163] According to an 18th embodiment which can be combined with the 16th or 17th embodiment, the co-scheduling information indicates that the base station is co-scheduling different mobile terminals within the at least one and / or another CDM group.

[0164] According to a 19th embodiment which can be combined with the 16th or 17th embodiment, the co-scheduling information indicates that the base station is co-scheduling at least several different mobile terminals within the at least one and / or another CDM group.

[0165] According to a 20th embodiment which can be combined with the 16th to 19th embodiments, the cooperative scheduling information is binary information indicating whether or not cooperative scheduling is performed in each of the plurality of CDM groups.

[0166] According to a 21st embodiment which can be combined with embodiments 16 to 20, the plurality of CDM groups are assigned consecutive indices, and each port of the plurality of CDM groups is assigned a consecutive index such that the index of the port increases together with the index of the plurality of CDM groups.

[0167] According to a 22nd embodiment which can be combined with embodiments 16 to 21, the cooperative scheduling information indicates cooperative scheduling only for CDM groups among the plurality of CDM groups that have an index equal to or greater than the index of at least one of the CDM groups.

[0168] According to a 23rd embodiment, which can be combined with embodiments 16 to 22, resources assigned to ports in a CDM group having an index smaller than the minimum index of the port shown in the control information for arranging the reference signal are known to be coordinately scheduled by the base station.

[0169] According to a 24th embodiment which can be combined with embodiments 16 to 23, the mapping means indexing the combination of layer and port mappings and the co-scheduling information.

[0170] According to a 25th embodiment, which can be combined with embodiments 16 to 24, the resource assigned to the port comprises two resource element configurations, the first resource element configuration comprising a comb and a cyclic shift of a reference signal, the comb comprising either a subcarrier having an odd subcarrier index or a subcarrier having an even subcarrier index, and the second resource element configuration comprising frequency division multiplexing and frequency division orthogonal cover code (OCC), the method further comprising receiving an indicator from a base station during operation indicating whether the first resource element configuration or the second resource element configuration is being used.

[0171] According to a 26th aspect which can be combined with aspects 16 to 25, parameters defining a configuration that allocates each resource to a port for carrying a reference signal are received via a radio resource control (RRC) protocol.

[0172] According to a 27th embodiment, which can be combined with embodiments 16 to 26, the control information, which indicates one set of layer-port mapping combinations and the co-scheduling information, is received via a physical downlink control channel (PDCCH).

[0173] According to a 28th embodiment, which can be combined with embodiments 16 to 27, the reference signal is a forward demodulation reference signal.

[0174] According to a 29th aspect which can be combined with the 16th to 28th aspects, the method includes a further step of performing the data transmission and / or reception by applying the combination of layer and port mappings described above.

[0175] According to a 30th aspect which can be combined with the 16th to 29th aspects, the method includes the further step of performing interference compensation for the received reference signal and / or rate matching for the data transmission and / or reception.

[0176] According to the 31st aspect, a base station is proposed for transmitting and / or receiving data in layers to and from a mobile terminal (210) using multiple antennas in a mobile communication system, the base station comprising circuits (270, 280) that, when in operation, transmit to the mobile terminal parameters defining a configuration that assigns each resource, grouped into multiple code division multiplexing (CDM) groups, to a port for carrying a reference signal, and transmit to the mobile terminal control information indicating one of a set of layer-to-port mapping combinations applied to position the reference signal at a port in at least one CDM group for transmitting and / or receiving data, wherein the control information additionally indicates coordinate scheduling information for the at least one CDM group and / or at least one other CDM group among multiple CDM groups for the same data transmission and / or reception.

[0177] According to the 32nd aspect, a method is proposed to be performed by a base station in a mobile communication system for transmitting and / or receiving data in layers to and from a mobile terminal using multiple antennas, the method comprising the steps of: transmitting to the mobile terminal parameters defining a configuration that assigns each resource, grouped into multiple code division multiplexing (CDM) groups, to a port for carrying a reference signal; and transmitting to the mobile terminal control information indicating one of a set of layer-to-port mapping combinations to be applied to position the reference signal at a port in at least one CDM group for transmitting and / or receiving data, wherein the control information additionally indicates coordinate scheduling information for the at least one CDM group and / or at least one other CDM group among the multiple CDM groups for the same data transmission and / or reception.

Claims

1. It is a base station, The circuit and the said circuit are It transmits parameters that define a configuration for assigning each resource to a port for carrying a reference signal, and each resource is grouped into multiple code division multiplexing (CDM) groups. To transmit control information indicating one of a set of layer / port mapping combinations, which is applied to place a reference signal on the port of at least one CDM group for data transmission and / or reception. The control information indicates coordinate scheduling information for at least one CDM group and / or at least one other CDM group among a plurality of CDM groups for the same data transmission and / or reception. A transmitting / receiving unit that controls the transmission and / or reception of data within a layer based on the aforementioned cooperative scheduling information, Equipped with, Each resource assigned to the port includes two resource element configurations: The first resource element configuration includes a comb and a cyclic shift of a reference signal, wherein the comb is composed of either a subcarrier having an odd subcarrier index or a subcarrier having an even subcarrier index. The second resource element configuration includes frequency division multiplexing and frequency division quadrature cover code (OCC), The circuit further transmits an indicator to the mobile terminal indicating whether the first resource element configuration is being used or the second resource element configuration is being used. Base station.

2. The control information indicates coordinate scheduling information for all or a subset of the plurality of CDM groups. The base station according to claim 1.

3. The aforementioned cooperative scheduling information is The base station indicates that it is coordinating scheduling different mobile terminals within the at least one and / or other CDM group. The base station indicates that it is coordinating scheduling of at least several different mobile terminals within the at least one and / or other CDM group, and This is binary information indicating whether or not cooperative scheduling is present in each of the aforementioned multiple CDM groups. It is at least one of the things The base station according to claim 1.

4. The aforementioned multiple CDM groups are assigned consecutive indices, and each port of the multiple CDM groups is assigned a consecutive index such that the index of the port increases together with the index of the multiple CDM groups. The base station according to claim 1.

5. The aforementioned cooperative scheduling information indicates cooperative scheduling for a CDM group among the plurality of CDM groups that has an index equal to or greater than the index of at least one of the CDM groups. The base station according to claim 1.

6. Resources assigned to ports in a CDM group having an index smaller than the minimum index of the port shown in the control information for arranging the reference signal are coordinately scheduled by the base station. The base station according to claim 1.

7. The aforementioned mapping means indexing the combination of the layer / port mapping and the co-scheduling information. The base station according to claim 1.

8. The parameters defining the configuration for assigning each resource to a port for carrying a reference signal are transmitted via the Radio Resource Control (RRC) protocol and / or The control information, which represents one of the sets of layer / port mapping combinations and the cooperative scheduling information, is transmitted via the physical downlink control channel (PDCCH). The base station according to claim 1.

9. The aforementioned reference signal is a reference signal for forward demodulation. The base station according to claim 1.

10. The transmitting and receiving unit performs the data transmission and / or reception by applying the layer / port mapping combination shown above. and / or, Interference compensation for the transmitted reference signal and / or rate matching for the data transmission and / or reception are performed. The base station according to claim 1.

11. A method performed by a base station, The steps include sending parameters to a mobile terminal that define a configuration for assigning each resource to a port for carrying a reference signal, and that each resource is grouped into multiple code division multiplexing (CDM) groups. The steps include transmitting control information indicating one of a set of layer / port mapping combinations applied to place a reference signal on a port of at least one CDM group for data transmission and / or reception, The control information indicates coordinate scheduling information for at least one CDM group and / or at least one other CDM group among a plurality of CDM groups for the same data transmission and / or reception. The steps include controlling the transmission and / or reception of data within a layer based on the aforementioned cooperative scheduling information, Includes, Each resource assigned to the port includes two resource element configurations: The first resource element configuration includes a comb and a cyclic shift of a reference signal, wherein the comb is composed of either a subcarrier having an odd subcarrier index or a subcarrier having an even subcarrier index. The second resource element configuration includes frequency division multiplexing and frequency division quadrature cover code (OCC), Further transmit an indicator to the mobile terminal indicating whether the first resource element configuration or the second resource element configuration is being used. method.

Images