JP7435838B2 - User equipment and base stations - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention Non-limiting exemplary embodiments of the present disclosure relate generally to the field of wireless communication technology, and more particularly to methods and apparatus for reference signal transmission and reception in a wireless communication system.

New radio access systems, also called NR systems or networks, are the next generation communication systems. At the Radio Access Network (RAN) #71 meeting for the 3rd Generation Partnership Project (3GPP) Working Group, a study of NR systems was approved. NR Systems considers frequencies up to 100 GHz with the aim of a single technical framework that addresses all usage scenarios, requirements and deployment scenarios defined in Technical Report TR 38.913, including enhanced mobile Requirements include broadband, large-scale machine-type communications, and ultra-reliable and low-latency communications.

Initial work on this research item should assign high priority to gaining a common understanding of what is required in terms of wireless protocol structure and architecture, and focus on advances in the following areas:
- Basic physical layer signal structure for new RATs - Potential support for OFDM-based waveforms, non-orthogonal waveforms and multiple access - FFS: other waveforms if they exhibit legitimate gain - Basic frame structure - Channels Coding method

Additionally, it is also necessary to study and identify the technical features needed to enable new wireless access, such as:
Efficient multiplexing of traffic for different services and use cases on the same contiguous spectrum block

Additionally, dynamic/flexible bandwidth allocation and configurable RS patterns (including density) were also agreed upon in RAN1.

Dynamic/flexible bandwidth allocation means that dynamic/flexible and UE-specific bandwidth allocation is supported in the NR. Therefore, in such cases, the UE does not know the total system bandwidth on the network side, different UEs may require different reference signal sequences, and existing RS sequence generation solutions can be used to create a shared RS for the UE. It is not possible to generate a sequence. On the other hand, the RS pattern can also be configurable (e.g., configurable density in the time/or frequency domain), and therefore the legacy RS sequence can meet the requirements for different patterns, especially with regard to multi-user scheduling. I can't.

In the present disclosure, a new solution for transmitting and receiving reference signals in a wireless communication system is provided to alleviate or at least alleviate at least some of the problems in the prior art.

According to a first aspect of the present disclosure, a reference signal transmission method in a wireless communication system is provided. The method comprises: generating a common reference signal sequence shared by at least some of the terminal devices each assigned their own reference signal transmission configuration based on a frequency range configuration on the network side; transmitting a sequence and sequence configuration information to a terminal device, the sequence configuration information indicating parameters by which an initial reference signal sequence transmitted to the terminal device can be obtained.

According to a second aspect of the present disclosure, a method of reference signal reception in a wireless communication system is provided. This method includes receiving a reference signal sequence transmitted from a network side and sequence configuration information indicating parameters for obtaining an initial reference signal sequence transmitted to the terminal device, and the sequence configuration obtaining an initial reference signal sequence for the terminal device based on the information.

According to a third aspect of the present disclosure, an apparatus for reference signal transmission in a wireless communication system is provided. The apparatus includes a reference signal generation module and a sequence and information transmission module. The reference signal generation module is configured to generate a common reference signal sequence shared by at least some of the terminal devices each assigned their own reference signal transmission configuration based on a frequency range configuration on the network side. Ru. The sequence and information transmission module is configured to transmit the common reference signal sequence and sequence configuration information to a terminal device, and the sequence configuration information is configured to obtain an initial reference signal sequence transmitted to the terminal device. Indicates the parameters that can be used.

According to a fourth aspect of the present disclosure, an apparatus for receiving a reference signal in a wireless communication system is provided. The apparatus includes a sequence and signal reception module and a sequence acquisition module. The sequence and signal receiving module is configured to receive a reference signal sequence transmitted from the network side and sequence configuration information indicating parameters for obtaining an initial reference signal sequence transmitted to the terminal device. be done. The sequence acquisition module is configured to acquire the initial reference signal sequence for the terminal device based on the sequence configuration information.

According to a fifth aspect of the present disclosure, there is provided a computer readable storage medium embodying computer program code which, when executed, performs a method according to any embodiment of the first aspect. The device is configured to cause the device to perform the following operations.

According to a sixth aspect of the present disclosure, there is provided a computer readable storage medium embodying computer program code which, when executed, performs a method according to any embodiment of the second aspect. The device is configured to cause the device to perform the following operations.

According to a seventh aspect of the present disclosure, there is provided a computer program product comprising a computer readable storage medium according to said fifth aspect.

According to an eighth aspect of the present disclosure, there is provided a computer program product comprising a computer readable storage medium according to the sixth aspect.

In embodiments of the present disclosure, a low complexity reference signal sequence solution for wireless communication systems (particularly new radio access systems) with dynamic bandwidth allocation and/or configurable reference signal patterns is proposed. The common reference signal sequence is generated and shared by at least some terminal devices regardless of the reference signal transmission configuration, such as bandwidth allocation and/or reference signal pattern configuration. Therefore, it is possible to perform RS measurements and multi-user scheduling for UEs even if they are configured with different bandwidth allocations and/or configurable reference signal patterns. Moreover, since the reference signal from interfering cells is easier to obtain, it can achieve better interference cancellation. Furthermore, it only requires the terminal equipment to generate a small number (e.g. only one) of reference signal sequences for different band allocations and/or RS pattern configurations, which means a less complex solution. .

The above and other features of the present disclosure will become more apparent through the detailed description of embodiments illustrated in the drawings with reference to the accompanying drawings. The same reference numbers represent the same or similar elements throughout the drawings.

FIG. 1 schematically shows a system bandwidth configuration in an LTE system.

FIG. 2 schematically illustrates an example of potential problems associated with dynamic bandwidth allocation in NR systems.

FIG. 3 schematically illustrates an example of a potential problem associated with configured RS patterns in an NR system.

FIG. 4 schematically depicts a flowchart of a method for reference signal transmission according to an example embodiment of the present disclosure.

FIG. 5 schematically depicts a common RS sequence and an RS sequence for respective UEs with different frequency band allocations, according to an exemplary embodiment of the present disclosure.

FIG. 6 schematically depicts the generation of an exemplary common RS sequence according to another embodiment of the present disclosure.

FIG. 7 schematically depicts the generation of an exemplary common RS sequence using fixed indexes according to a further embodiment of the present disclosure.

FIG. 8 schematically illustrates the generation of an exemplary common RS sequence using fixed indexes according to yet a further embodiment of the present disclosure.

FIG. 9 schematically depicts an example common RS sequence for a UE with a configurable RS pattern according to a still further embodiment of the present disclosure.

FIG. 10 schematically depicts common RS sequences and RS sequences for respective UEs with different RS densities, according to an embodiment of the present disclosure.

FIG. 11 schematically depicts a common RS sequence and an RS sequence for respective UEs with different RS configurations in the time domain, according to another example embodiment of the present disclosure.

FIG. 12 schematically depicts common RS sequences and RS sequences for respective UEs with different band allocations in the frequency domain and different RS configurations in the time domain, according to another exemplary embodiment of the present disclosure.

FIG. 13 schematically illustrates different variable modes of modulation symbols in an RS sequence according to embodiments of the present disclosure. FIG. 14 schematically illustrates different variable modes of modulation symbols in an RS sequence according to embodiments of the present disclosure. FIG. 15 schematically illustrates different variable modes of modulation symbols in an RS sequence according to embodiments of the present disclosure.

FIG. 16A schematically illustrates the generation of common RS sequences for symbols of different densities according to an embodiment of the present disclosure. FIG. 16B schematically illustrates the generation of a common RS sequence for symbols of different densities according to an embodiment of the present disclosure.

FIG. 17 schematically depicts a flowchart of a method for reference signal reception according to an embodiment of the present disclosure.

FIG. 18 schematically depicts a block diagram of an apparatus for reference signal transmission according to an embodiment of the present disclosure.

FIG. 19 schematically depicts a block diagram of an apparatus for reference signal reception according to an embodiment of the present disclosure.

FIG. 20 illustrates an apparatus 2010 that can be embodied in or included in a serving node, such as a base station in a wireless network, and a terminal device, such as described herein as a UE. Further shown is a simplified block diagram of an apparatus 2020 that may be embodied or included therein.

The solutions provided in the present disclosure will be described in detail through embodiments below with reference to the accompanying drawings. It is to be understood that these embodiments are presented solely to enable those skilled in the art to better understand and practice the present disclosure, and are not intended to limit the scope of the present disclosure in any way. .

Various embodiments of the present disclosure are illustrated in block diagrams, flowcharts, and other diagrams in the accompanying drawings. Each block within a flowchart or block may represent a module, program, or portion of code that includes one or more executable instructions to perform a particular logical function, and this disclosure excludes unnecessary blocks. Indicated by dotted lines. Further, although these blocks are shown in a particular order for performing the steps of the method, in practice they may not necessarily be performed in the precise order shown. For example, they may be performed in reverse order or simultaneously, depending on the nature of each operation. Each block in the block diagrams and/or flowcharts, and combinations thereof, may be implemented by a dedicated hardware-based system or by a combination of dedicated hardware and computer instructions to perform a particular function/operation. obtain.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the art, unless clearly defined otherwise herein. All references to "a/an/the/said [an element, device, component, means, step, etc.]" shall be taken as reference to at least one instance of said element, device, component, means, unit, etc. and without excluding a plurality of such devices, components, means, units, steps, etc., unless expressly stated otherwise. Furthermore, the indefinite article "a/an" as used herein does not exclude a plurality of such steps, units, modules, devices, objects, etc.

Further, in the context of this disclosure, User Equipment (UE) refers to a terminal, a mobile terminal (MT), a subscriber station, a mobile subscriber station, a mobile station (MS), or an access terminal. (AT: Access Terminal), and may include some or all of the functions of a UE, terminal, MT, SS, mobile subscriber station, MS, or AT. Further, in the context of this disclosure, the term "BS" refers to, for example, Node B (NodeB or NB), Evolved Node B (eNodeB or eNB), gNB (NodeB in NR), Radio Header (RH). , a remote radio head (RRH), a relay, or a low power node such as a femto, pico, etc.

In the following, to facilitate understanding of embodiments of the present disclosure, Channel State Information-Reference Signal (CSI-RS) sequence generation in the LTE system will first be described.

は、以下によって定義される。

ここで、ｎ_ｓは無線フレーム内のスロット番号であり、

はスロット内のＯＦＤＭのシンボル番号である。c（i）は擬似乱数列生成器によって生成された擬似乱数列で、次のように初期化される。

各ＯＦＤＭシンボルの先頭に以下が付加される。

そして、ここで、量

がよりレイヤの高い層によって構成されない場合、量

は

に等しい。 According to the generation of CSI-RS in LTE, the reference signal sequence

is defined by:

Here, n _s is the slot number within the radio frame,

is the OFDM symbol number within the slot. c(i) is a pseudorandom number sequence generated by a pseudorandom number sequence generator, and is initialized as follows.

The following is added to the beginning of each OFDM symbol.

And here, the amount

If is not composed by a higher layer, then the amount

teeth

be equivalent to.

は、以下に従ったアンテナポートｐ上の基準シンボルとして使用される複素数値変調シンボル

にマッピングされるものとする。

In a subframe configured for CSI reference signal transmission, the reference signal sequence

is a complex-valued modulation symbol used as a reference symbol on antenna port p according to

shall be mapped to

Therefore, it is clear that the CSI-RS sequence is generated with a fixed maximum length N _RB ^{max, DL} and a set length N _RB ^DL . The configuration length N _RB ^DL is associated with the configuration of system bandwidth in the network.

The index for CSI-RS sequence generation is known to the UE, N _RB ^{max, DL} is fixed to 110, N _RB ^DL is obtained from the physical broadcast channel (PBCH), and the CSI-RS is This is full band one. Therefore, the generated CSI-RS can be shared by all UEs in the cell.

Therefore, in LTE systems, CSI-RS sequences are generated with a fixed maximum length, and each of the six different configurations of system bandwidth has the same center frequency and the generated CSI-RS The sequence is fixed. Therefore, for the same cell ID, the CSI-RS sequence is common to all UEs in the cell.

However, in an NR system the situation will be different. As mentioned above, dynamic/flexible bandwidth allocation is supported in NR systems, so the UE does not know the total system bandwidth on the network side. Furthermore, different UEs may require different reference signal sequences, as different UEs may be assigned different frequency bands. With existing RS sequence generation solutions, it is not possible to generate a single RS sequence that can be shared for UEs.

FIG. 2 shows an example of potential problems associated with dynamic bandwidth allocation in NR systems. As shown in Fig. 2, there are three different UEs, namely UE1, UE2, and UE3, which are located within the same cell but configured with UE-specific frequency bands for scheduling/measurement, Each of them is only a part of the total system bandwidth configured on the network side. As shown in FIG. 2, the frequency bands of different UEs may be separated or may partially or completely overlap. From the UE's point of view, the bandwidth allocation should be obvious since its total bandwidth depends on the RF capabilities and it is not mandatory to know the system bandwidth on the network side.

In such cases, RS configuration with dynamic bandwidth allocation may cause some problems. For example, for a cell or beam specific RS, it shall be common or shared by a group of UEs, like the RS for CSI measurements. Furthermore, considering multi-user MIMO scheduling, the demodulated RS should also be unified for orthogonally co-scheduling. Even for different sequences of RSs for quasi-orthogonal or inter-cell/intra-cell interference management, the RS sequence should be able to be known to other UEs for a high degree of interference cancellation. In such cases, RS configuration with dynamic bandwidth allocation would not allow RS sharing, but would be problematic.

Furthermore, in an NR system, the UE may be configured with a UE-specific RS pattern (eg, UE-specific RS density) in the time/frequency domain. In such cases, it is also not possible to share a common RS with existing RS generation solutions. However, common RS generation may also be beneficial in many cases, especially when the RS pattern is dynamically changed, as the UE can extract the necessary RSs from the common sequence. Additionally, common sequences can facilitate multi-user scheduling.

しかしながら、そのような場合、図３に示されるように、異なるＲＳパターンに対して直交性は保証され得ず、これは各ＵＥに対するチャネルＨ１およびＨ２が推定できないことを意味する。さらに、各ＵＥは、他のＵＥに干渉を引き起こす可能性があり、高度なＵＥでは、他のＵＥからの干渉を差し引くことができない。したがって、レガシーＲＳシーケンス生成は、異なるＲＳパターン、特にマルチユーザスケジューリングのために、要件も満たすことができない。 As shown in FIG. 3, if the UE generates their RS sequences separately, the signals received on the RE are _Y1 and _Y2 , which are respectively expressed as:

However, in such a case, orthogonality cannot be guaranteed for different RS patterns, as shown in FIG. 3, which means that channels H1 and H2 for each UE cannot be estimated. Furthermore, each UE can cause interference to other UEs, and advanced UEs cannot subtract interference from other UEs. Therefore, legacy RS sequence generation cannot also meet the requirements due to different RS patterns, especially multi-user scheduling.

In view of the above, in this disclosure, a common RS sequence design solution is proposed that is independent of UE bandwidth or RS pattern configuration. The common RS sequence design allows groups of UEs with their own RS transmission configurations to share a common RS sequence such as their RS for measurement and multi-use scheduling. Furthermore, since RSs from interfering cells are easier to obtain, it may achieve better interference cancellation. Furthermore, the UE only needs to generate several sequences (eg only one) for different band allocation/pattern configurations, which means less complexity in RS sequence generation.

In the following, a solution for reference signal transmission and reception as proposed herein will be explained with reference to the accompanying drawings. However, it is noted that these descriptions are for illustrative purposes only and this disclosure is not limited thereto.

Reference is first made to FIG. 4, which schematically depicts a flowchart of a method 400 of reference signal transmission in a wireless communication system according to an embodiment of the present disclosure. Method 400 may be performed at a serving node, such as a BS, NodeB or NB, for example.

As shown in FIG. 4, first, in step 401, a common reference signal sequence is generated based on the frequency range configuration on the network side, and the common reference signal has their own reference signal transmission configurations assigned to each of the at least one Can be shared by several terminal devices.

In one embodiment of the present disclosure, a common reference signal sequence is generated at the network side based on the system bandwidth. In other words, the length of the common reference signal sequence is determined based on at least the total system bandwidth on the network side.

As shown in Fig. 5, the common reference signal sequence R_i consists of R_0, R_1, R_2, ..., R_M-2, R_M-1, where M is the length of the reference signal R_i and depends on the system bandwidth on the network side. At least relevant. Furthermore, it may also be further related to the minimum subcarrier spacing (SCS).

、ｃｅｌｌ＿ＩＤ Ｎ^ＩＤ、ＵＥ＿ＩＤ Ｕ^ＩＤ、ＣＰタイプＮ_ＣＰ、ＳＣＳ構成のインデックスＮ_ＳＣＳ、リンクタイプＮ_{ｌｉｎｋ＿ｔｙｐｅ}等の少なくとも一つに関連するパラメータを用いて計算することができる。以下、本開示の例示的な実施形態では、Ｃ＿ｉｎｉｔを決定することができる。

ここで、ａ_ｉは各要素の係数であり、ｉ＝０、１、…、であり、パラメータ数Ｎ_ＳＣＳは、サブキャリア間隔構成のパラメータであり、Ｎ_ＳＣＳの値は、一組の値から選択することができ、サブキャリア間隔に対応する各値Ｎ_{ｌｉｎｋ＿ｔｙｐｅ}は、初期値がダウンリンク、アップリンク、またはサイドリンクであることを示すリンクタイプのパラメータである。端末装置の少なくともいくつかについては、それらは同じＵ^ＩＤを割り当てられ、したがって、それらは生成されたＲＳシーケンスを共有することができることに留意されたい。 The sequence R_i can be defined by a pseudo-random sequence that can be initialized with an initial value C_init by a pseudo-random sequence generator. The initial value C_init is the slot index n _s and the symbol index

, cell_ID N ^ID , UE_ID U ^ID , CP type N _CP , SCS configuration index N _SCS , link type N _{link_type} , and the like. Hereinafter, in exemplary embodiments of the present disclosure, C_init may be determined.

Here, a _i is a coefficient of each element, i = 0, 1, ..., the number of parameters N _SCS is a parameter of the subcarrier spacing configuration, and the value of N _SCS is determined from a set of values. Each value N _{link_type} that can be selected and corresponds to the subcarrier spacing is a link type parameter whose initial value indicates downlink, uplink, or sidelink. Note that for at least some of the terminal devices, they are assigned the same U ^ID , so they can share the generated RS sequences.

In one embodiment of the present disclosure, the table below may be used to indicate subcarrier spacing configurations.
Table 1 Example of subcarrier interval configuration

Regarding the link type parameter N _{link_type} , the following table can be used as a way to indicate the link type.
Table 2 Example of link type display

For downlink or uplink, the RS sequences are symmetric and the sequences are generated with different initial values.

Therefore, in a common RS sequence with length M as shown in Fig. 5, for different UEs with different bandwidth configurations, e.g. configured in different frequency ranges/positions within the system frequency band, their Each RS sequence starts from a different index of the common RS sequence and has a different length. As shown, the RS sequence of UE1 may start at i_start_1 (R_3 of the common RS sequence) and end at i_end_1 (R_10 of the common RS sequence). The RS sequence of UE2 may start with i_start_2 (R_i of the common RS sequence) and end with i_end_2 (R_M-2 of the common RS sequence). The RS sequence of UE3 may start with i_start_3 (R_2 of the common RS sequence) and end with i_end_3 (R_i+2 of the common RS sequence). In other words, the RS sequence for each UE will correspond to their own allocated frequency band. Here, the start index of the UE's RS sequence is also referred to as the UE's RS sequence index.

Returning to FIG. 4, in step S402, a common reference signal sequence and sequence configuration information are transmitted to the terminal device, where the sequence configuration information indicates parameters by which the initial reference signal sequence transmitted to the terminal device can be obtained. .

The common RS sequence can be transmitted to at least some terminal devices, each terminal device receiving the RS sequence for itself, respectively, on their own allocated band. However, the terminal also needs to know the initial modulation symbols of the RS sequence (ie, the initial RS sequence without going through the channel), for example to perform channel measurements or simultaneous scheduling. Thereby, sequence configuration information indicating parameters by which the initial reference signal sequence transmitted to the terminal device can be acquired can also be transmitted to the terminal device. The parameters carried in the sequence configuration information allow the terminal device to obtain the RS sequence from a common RS sequence generated in a manner similar to that described in step 401.

In one embodiment of the present disclosure, sequence configuration information may be sent to the terminal device in an explicit manner. For example, the sequence configuration information may include sequence position information indicating the position where the reference signal sequence for the terminal device is located in the common reference signal sequence. Sequence position information may include any of the following:
1) Start index and end index of the reference signal sequence for the terminal device, i.e. i_start_ue and i_end_ue.
2) Start index and length of the reference signal sequence for the terminal, i.e. i_start_ue and m_ue.
3) End index and length of the reference signal sequence for the terminal, i.e. i_end_ue and m_ue.

Furthermore, it can be seen that unlike the RS generation solution in LTE, the index of the RS sequence for the terminal device does not correspond to the index of the frequency band. In such a case, it is also possible to transmit an offset value for the frequency configuration of the terminal device to the terminal device. The offset value indicates the offset of the index of the RS sequence for the terminal device with respect to the index of the frequency band assigned to the terminal device. In another embodiment of the present disclosure, it is also possible to send an offset value for a fixed frequency location. In this way, the terminal device can also know how to obtain its RS sequence.

In another embodiment of the present disclosure, it may also send the length M of the common RS sequence to the UE.

In another embodiment of the present disclosure, sequence configuration information may also be transmitted implicitly. In other words, sequence configuration information can be implied from other parameters. Examples of these parameters include, but are not limited to, the boundaries/length of the frequency band assigned to the terminal, the frequency band configuration of the terminal, and the sequence generation initial value of the terminal.

As mentioned above, the RS sequence for a terminal corresponds to its own allocated bandwidth, and therefore the boundaries/length of the frequency band assigned to the terminal implicitly carries sequence configuration information. can be used to indicate Furthermore, if the band of the terminal device is selected from a group of predetermined bands with a predetermined indication value, the frequency band configuration allows the terminal device to learn the assigned frequency band from the predetermined value and therefore to read the sequence configuration information. can be obtained. Furthermore, it is also possible to send a sequence initialization value C_init_ue to the terminal device, with which the terminal device can generate the RS sequence from itself. C_init_ue is terminal-specific, but is derived from C_init for a common RS sequence, thus making the symbols of the RS sequences for different terminals the same at the same frequency or time position.

Note that although the present disclosure is described above with embodiments generated based on system bandwidth on the network side, the present disclosure is not limited thereto. In one embodiment of the present disclosure, the common RS sequence may be generated based on the frequency band configured for the node serving the terminal device, rather than the entire system bandwidth. It should be appreciated that different serving nodes may be assigned different frequency bandwidths, and in such a case it is also possible for the network to generate a common RS sequence corresponding to the assigned frequency bandwidths.

For example, for different frequency range configurations, the starting index for RS sequence generation may be different. However, in such a case, a common reference signal sequence can be generated based on a frequency range that covers all possible frequency ranges of different frequency range configurations. In such a case, it will ensure that the RS sequences for different frequency range configurations have the same value at the same frequency location.

For example, as shown in FIG. 6, there are two different frequency range configurations, frequency range 1 and frequency range 2. In other words, two Transmission and Reception Points (TRPs)/cells or two configurations of one cell are configured with different frequency band/or numerology assignments. If the UE needs to measure TRP/intercell interference, the RS sequences should be the same in an area (eg, for the overlap part). In this case, it is possible to generate a common sequence from the same starting position idx_rs corresponding to the lower limits of the two frequency ranges.

For each UE, an index idx_rs for RS generation may be indicated to the UE, and an offset value k for idx_rs may also be indicated to the UE. In such a case, the UE may determine the starting index of its RS sequence, for example as idx_rs1=idx_rs+k. Alternatively, it can be independent from idx_rs and indicate to the UE the starting index idx_b1 for band/numerology allocation for the UE. RS sequences with two different frequency range settings can be obtained from a common RS sequence generated from idx_rs. RS sequence parameters (eg, for serving cell and neighboring cells) may be indicated to the UE. The parameters may include at least one of a start index, length, end index, offset value, numerology, and the like.

In one embodiment of the present disclosure, the different frequency range configurations may have at least one of different subcarrier spacing configurations and different cyclic prefix configurations.

In embodiments of the present disclosure, fixed indexes may be used for RS sequence generation for different numerologies. The index may be detected by the UE, for example by a synchronization signal. In other words, for numerologies in different numerology configurations, a common reference signal sequence can be generated based on a frequency range that covers all possible frequency ranges of the numerology. Furthermore, a fixed index and an offset value for the fixed index can be used to indicate sequence configuration information.

FIG. 7 is a diagram illustrating the generation of an example common RS sequence using fixed indexes, according to one embodiment of the present disclosure. As shown, for various numerology configurations including, for example, three numerologies, for each of numerologies 1, 2, and 3 in these numerology configurations, the common RS sequence generation is performed using fixed indexes, i.e., indexes 1, 2, and 3, respectively. or 3 can be used. That is, the common RS sequence generation is generated based on a frequency range that covers all possible frequency ranges of the numerology, and a fixed index and offset value are used as sequence configuration information. In this way it is possible to keep the reference signal the same at the same frequency position.

FIG. 8 is a diagram illustrating example common RS sequence generation with fixed indexes according to another embodiment of the present disclosure. This solution is substantially similar to the solution of FIG. 7, except that the index is fixed at the center position of each frequency range. That is, all frequency ranges have the same center frequency location.

In another embodiment of the present disclosure, the index for RS sequence generation for different numerologies may be configured by the network.

Hereinafter, the present disclosure will be described primarily with reference to dynamic bandwidth allocation, but the present disclosure is not limited thereto. The present disclosure may also be used in configurable RS patterns that may include at least one of a reference signal density configuration in the time domain, a reference signal density configuration in the frequency domain, and a reference signal frequency offset configuration. In such cases, it would be advantageous if a common reference signal sequence is generated further based on the entire set of resource elements used for RS transmission in different reference signal configurations.

As shown in Figure 9, the RS patterns are nested in the time-frequency domain, and if configurable RS patterns are supported in the NR system, different RS patterns, with different offsets, with different densities, with different transmissions. / Not accompanied, etc., as shown in the right diagram in FIG. 9 may be possible. In such a case, as shown in the left diagram of Fig. 9, the entire set of resource elements used for RS transmission in different RS configurations can be obtained, so that the modulation symbols on the RE and associated REs are You can choose everything from the entire set. It is then possible to generate a common RS sequence further based on the overall set of resource elements used for RS transmission with different reference signal configurations. Therefore, the RS sequence for the RS pattern of the terminal device can be obtained from the common RS sequence.

For UEs with different RS patterns, such as different densities, their respective RS The sequence obtains a common RS sequence.

、またはＲ＿ｉ、ｉ＝１、３、５…である。 FIG. 10 schematically depicts common RS sequences and RS sequences for respective UEs with different RS densities, according to embodiments of the present disclosure. As shown, the common RS sequence has length M, so the sequence can be represented by R_i, i=0, 1, . . . , M-1. For UEs configured with different densities, the density configuration may be notified to the UE. For different density configurations, the UE can extract the required sequences from the common sequence R_i. For example, for a density UE of 1, the sequence is R_i, i = 0, 1, ..., M-1, and for a density UE of 1/2, the sequence is:

, or R_i, i=1, 3, 5...

Similarly, for different SCS configurations, the UE can also extract the required sequences from the common sequences.

ここで、ｉ＿ｓｔａｒｔはシーケンスの開始インデックス、ｉ＿ｅｎｄはシーケンスの終了インデックス、Ｋは密度のパラメータ（１／２密度構成の場合、Ｋ＝２）、または、ＳＣＳのパラメータ（Ｋ・ｋ０、ここで基準ＳＣＳはｋ０である）、ｏはオフセット構成である。これらのパラメータは、個別に設定することも、一緒に設定することもできる。基準ＳＣＳ ｋ０は、ネットワークによって構成することができる。たとえば、ネットワークによっては、基準ＳＣＳは１５ｋＨｚ、３０ｋＨｚ、６０ｋＨｚ、１２０ｋＨｚ、または２４０ｋＨｚである。 For example, for UEs with maximum density or minimum SCS k0, the sequence is R_i, i=0, 1,..., M-1. On the other hand, for UEs with density 1/K or SCS K*k0, the sequence can be expressed as:

Here, i_start is the start index of the sequence, i_end is the end index of the sequence, and K is the density parameter (K=2 in the case of 1/2 density configuration) or the SCS parameter (K・k0, where the reference SCS is k0), o is the offset configuration. These parameters can be set individually or together. The reference SCS k0 can be configured by the network. For example, depending on the network, the reference SCS is 15 kHz, 30 kHz, 60 kHz, 120 kHz, or 240 kHz.

In embodiments of the present disclosure, the RS sequences may be the same or generated with different initial values for different symbols/slots.

In another embodiment of the present disclosure, RS sequences may be generated for the time-frequency domain. The reference density within one PRB in the frequency domain can be represented by d0 (e.g. maximum density), the reference SCS can be represented by k0 (e.g. minimum SCS), and the reference density in the time domain can be represented by t0 (e.g. maximum density). ) can be expressed as The number of PRBs (relative to SCS k0) can be denoted by N, and the length in one symbol over the entire bandwidth can be denoted by L (e.g., L=N*d0), and the maximum of the sequence The length can be expressed by M (eg M=L*t0). The common sequence is R_i, i=0, 1, . . . , M-1. For UEs with different configurations, it can extract the required sequences from the common RS sequence.

For UEs configured with different SCS ki, their RS sequences can be extracted for each ki/k0, similar to the case shown in FIG. For UEs configured with different densities di in the frequency domain, their RS sequences can be extracted from the common RS sequence for each di/d0, again similar to the case shown in FIG. For UEs configured with different time densities ti, their RS sequences can be extracted from RS sequence groups, as shown in FIG. 11. For UEs configured with different patterns, their RS sequences can be extracted from the common RS sequence accordingly.

For UEs configured with different patterns in the time domain and different band allocations in the frequency domain, their respective RS sequences are the common RS sequences corresponding to their band allocations and their RS patterns, as shown in FIG. It can be extracted from.

In embodiments of the present disclosure, the RS modulation symbols within one symbol and one PRB are similar, and then the RS sequences of UEs with different densities in the frequency domain can be easily obtained.

In another embodiment of the present disclosure, the modulation symbols in the common reference signal sequence vary by one of a predetermined number of subcarriers in the frequency domain and a predetermined number of symbols in the time domain.

As shown in FIG. 13, the modulation symbols within the common RS sequence may vary by a predetermined number of subcarriers in the frequency domain. That is, within these subcarriers, the modulation symbols may be the same, but different from the modulation symbols in another predetermined number of subcarriers.

Alternatively, the modulated symbols in the common RS sequence may vary by a predetermined number of symbols in the time domain, as shown in FIG. 14. That is, the modulation symbols within a given number of symbols will be the same, but may be different from other given numbers of symbols.

Furthermore, the modulation symbols within the common RS sequence may also vary by time-frequency block, as shown in FIG. 15. That is, within the same time-frequency block, the modulation symbols will be the same, but different from other time-frequency blocks. The time-frequency blocks may have no frequency shift between them, as shown on the left side of FIG. 15, or a predetermined frequency shift, as shown on the right side of FIG. 15.

Additionally, the density of one RS in different symbols may be different as shown in FIG. 16A (without offset) and FIG. 16B (with offset). In such cases, you may have several options. In a first option, an RS sequence may be generated for a first symbol that includes an RS, and modulation symbols for subsequent symbols may be generated based on the first symbol within the same frequency location. For example, the same as the first offset within the same frequency location, or multiplied by the frequency offset (complex number). In the second option, one common RS sequence is generated for the time-frequency block, and the modulation symbols on different symbols are extracted from the common RS sequence. The third option is to initialize the RS sequence for each symbol.

In the NR system, Phase Tracking RS (PT-RS) is introduced, which is used to track phase noise or frequency offset and is a reference signal agreed at the RAN1 #87 conference. According to the consensus at the RAN1 #87 meeting, the density of PT-RS in the frequency domain may have considerable leeway. In such a case, a sequence of PT-RSs can be generated based on previous DMRSs at the same frequency location. That is, the PT-RS may be the same as, or multiplied by, the frequency offset (complex value) with the previous DMRS at the same frequency location. Alternatively, it is also possible to generate a PT-RS sequence using the set sequence index, and in that case, sequence setting information can be transmitted to the terminal device.

The operations related to the new RS solution on the network side have been described above. Hereinafter, with reference to FIG. 17, operations related to the new RS solution on the terminal device side will be described.

FIG. 17 further schematically depicts a flowchart of a method for reference signal reception according to an example embodiment of the present disclosure. Method 1700 may be implemented at a terminal device, such as a UE, or other similar terminal device.

As shown in FIG. 17, the method starts at step 1701, in which a terminal device such as a UE obtains a reference signal sequence transmitted from the network side and a reference signal sequence transmitted to the terminal device. and sequence configuration information indicating parameters that can be used.
In an embodiment of the present disclosure, the sequence configuration information may be explicit information that may include, for example, sequence position information indicating where the reference signal sequence for the terminal device is located within the common reference signal sequence. can. As an example, the sequence position information may include the start index and end index of the reference signal sequence for the terminal, the start index and length of the reference signal sequence for the terminal, the end index of the terminal relative to the offset value for the frequency configuration of the terminal. and the length of the reference signal sequence and an offset value relative to the fixed frequency position.

In another embodiment of the present disclosure, the sequence configuration information includes, for example, any one of the boundaries/length of the frequency band assigned to the terminal device, the frequency band configuration of the terminal device, and the sequence generation initial value of the terminal device. It can be implicit information indicated by other parameters included.

Next, in step 1702, an initial reference signal sequence for the terminal device may be obtained based on the sequence configuration information. At the terminal device, the terminal device may generate the common RS sequence in a manner similar to that described with reference to FIGS. 4 to 16. Therefore, the terminal device can extract its initial RS sequence based on the sequence configuration information received in step 1702. Therefore, the terminal device can know the initial RS sequence that does not go through the channel between the serving node such as a Node B and the terminal device such as the UE. In step 702, the initial RS sequence and the RS sequence in which the terminal is in its assigned frequency band may perform, for example, channel estimation or simultaneous scheduling.
In an embodiment of the present disclosure, obtaining an initial reference signal sequence for the terminal device may include obtaining an initial reference signal sequence for the terminal device based on sequence configuration information and a reference signal pattern for the terminal device. The reference signal pattern may include at least one of a reference signal density configuration in the time domain, a reference signal density configuration in the frequency domain, and a reference signal frequency offset configuration.

Therefore, in embodiments of the present disclosure, a low complexity reference signal sequence solution is proposed for wireless communication systems (particularly new radio access systems) with dynamic bandwidth allocation and/or configurable reference signal patterns; Regardless of the reference signal transmission configuration, such as bandwidth allocation and/or reference signal pattern configuration, one common reference signal sequence can be generated and shared by at least some terminal devices. Therefore, it is possible to perform RS measurements and multi-user scheduling for UEs even if they are configured with different bandwidth allocations and/or configurable reference signal patterns. Moreover, since the reference signal from interfering cells is easier to obtain, it can achieve better interference cancellation. Furthermore, it only requires the terminal equipment to generate a small number (e.g. only one) of common reference signal sequences for different band allocations and/or RS pattern configurations, which makes it a less complex solution. It means a plan.

Furthermore, the present disclosure also provides an apparatus for transmitting and receiving reference signals at a serving node and a terminal device, respectively, in a wireless communication system, which will be described next with reference to FIGS. 18 and 19.

FIG. 18 schematically depicts a block diagram of an apparatus 1800 for reference signal transmission in a wireless communication system according to an embodiment of the present disclosure. Apparatus 1800 may be implemented in a serving node, eg, a BS, such as a NodeB (NodeB or NB).

As shown in FIG. 18, apparatus 1800 may include a reference signal generation module 1801 and a sequence and information transmission module 1802. The reference signal generation module 1801 is configured to generate a common reference signal sequence shared by at least some terminal devices each assigned their own reference signal transmission configuration based on a frequency range configuration on the network side. obtain. The sequence and information transmission module 1802 is configured to transmit a common reference signal sequence and sequence configuration information to the terminal device, the sequence configuration information being configured to transmit a common reference signal sequence to the terminal device for obtaining an initial reference signal sequence transmitted to the terminal device. Indicates a parameter.

In one embodiment of the present disclosure, the sequence configuration information may include sequence position information indicating where the reference signal sequence for the terminal device is located in the common reference signal sequence.

In another embodiment of the present disclosure, the sequence position information includes a start index and an end index of the reference signal sequence for the terminal device, a start index of the terminal device and the length of the reference signal sequence, an end index of the terminal device and the length of the reference signal sequence. It may include the length and either an offset value for the frequency configuration of the terminal device or an offset value for the fixed frequency position.

In a further embodiment of the present disclosure, the sequence configuration information is indicated by any of the boundaries/length of the frequency band assigned to the terminal device, the frequency band configuration of the terminal device, and the sequence generation initial value of the terminal device. obtain.

In still further embodiments of the present disclosure, the network side frequency range configuration may include either a system bandwidth or a frequency band configured for a node serving a terminal device.

In still further embodiments of the present disclosure, the reference signal transmission configuration comprises at least one of a band allocation, a reference signal density configuration in the time domain, a reference signal density configuration in the frequency domain, and a reference signal frequency offset configuration. .

In another embodiment of the present disclosure, the reference signal generation module 1801 generates a common reference signal sequence for different frequency range configurations based on a frequency range that covers all possible frequency ranges of the different frequency range configurations. may be further configured to. The different frequency range configurations may have at least one of different subcarrier spacing configurations and different cyclic prefix configurations.

In further embodiments of the present disclosure, the reference signal generation module 1801 may be further configured to generate a common reference signal sequence further based on the total set of resource elements used for RS transmissions with different reference signal configurations.

In still further embodiments of the present disclosure, the modulation symbols in the common reference signal sequence vary by any of a time-frequency block, a predetermined number of subcarriers in the frequency domain, and a predetermined number of symbols in the time domain. obtain.

In still further embodiments of the present disclosure, a modulation symbol within a reference signal sequence within a symbol may be generated based on a modulation symbol within the reference signal sequence within a previous symbol within the same frequency location.

In another embodiment of the present disclosure, the reference signal sequence within a symbol may have at least one of a different density and a different frequency offset than the reference signal sequence within a previous symbol.

FIG. 19 further schematically depicts a block diagram of an apparatus 1900 for receiving a reference signal in a wireless communication system according to an embodiment of the present disclosure. Apparatus 1900 may be implemented in a terminal device, such as a UE, or other similar terminal device.

As shown in FIG. 19, apparatus 1900 may include a sequence and signal reception module 1901 and a sequence acquisition module 1902. The signal receiving module 1901 is configured to receive a reference signal sequence transmitted from the network side and sequence configuration information indicating parameters by which the reference signal sequence transmitted to the terminal device can be obtained. Can be done. Sequence acquisition module 1902 can be configured to acquire an initial reference signal sequence for a terminal device based on the sequence configuration information.

In an embodiment of the present disclosure, the sequence acquisition module 1902 may be further configured to obtain an initial reference signal sequence for the terminal device based on the sequence configuration information and the reference signal pattern for the terminal device.

Devices 1800 and 1900 have been described above with reference to FIGS. 18 and 19. Note that devices 1800 and 1900 may be configured to perform functions such as those described with reference to FIGS. 4-17. Therefore, for details regarding the operation of the modules within these devices, reference may be made to those descriptions made for the respective steps of the method with reference to FIGS. 4 to 17.

It is further noted that components of devices 1800 and 1900 may be implemented in hardware, software, firmware, and/or any combination thereof. For example, components of devices 1800 and 1900 may each be implemented by a circuit, a processor, or any other suitable selection device.

Those skilled in the art will understand that the above-described examples are illustrative only, and not limiting, and the present disclosure is not limited thereto. Many variations, additions, deletions, and modifications can be easily conceived from the teachings provided herein, and all such variations, additions, deletions, and modifications fall within the protection scope of the present disclosure.

Further, in some embodiments of the present disclosure, each of devices 1800 and 1900 may include at least one processor. At least one processor suitable for use with embodiments of the present disclosure may include, by way of example, both general-purpose processors and special-purpose processors, now known or developed in the future. Each of devices 1800 and 1900 may further include at least one memory. The at least one memory can include, for example, semiconductor memory devices such as RAM, ROM, EPROM, EEPROM, and flash memory devices. At least one memory may be used to store a program of computer-executable instructions. Programs can be written in any high-level and/or low-level compatible or interpretable programming language. According to embodiments, computer-executable instructions may be configured to cause devices 1800 and 1900 to perform operations in accordance with at least the methods described with reference to each of FIGS. 4-17 using at least one processor.

FIG. 20 shows an apparatus 2010 that can be embodied as or included in a serving node, such as a base station in a wireless network, and a terminal device, such as a UE, as described herein. Further shown is a simplified block diagram of an apparatus 2020 that can be used or included therein.

Device 2010 comprises at least one processor 2011, such as a data processor (DP), and at least one memory (MEM) 2012 coupled to processor 2011. Apparatus 2010 further includes a transmitter TX and receiver RX 2013 coupled to processor 2011, which is operable to communicatively connect to apparatus 2020. The MEM 2012 stores a program (PROG: PROGram) 2014. PROG 2014 may include instructions that, when executed on associated processor 2011, enable apparatus 2010 to operate in accordance with embodiments of the present disclosure, such as method 400. The combination of at least one processor 2011 and at least one MEM 2012 may form processing means 2015 adapted to implement various embodiments of the present disclosure.

Device 2020 comprises at least one processor 2021, such as a DP, and at least one MEM 2022 coupled to processor 2021. Device 2020 may further include a suitable TX/RX 2023 coupled to processor 2021 that may be operable for wireless communication with device 2010. MEM2022 stores PROG2024. PROG 2024 may include instructions that, when executed on associated processor 2021, enable apparatus 2020 to operate in accordance with embodiments of the present disclosure, eg, to perform method 1700. The combination of at least one processor 2021 and at least one MEM 2022 may form processing means 2025 adapted to implement various embodiments of the present disclosure.

Various embodiments of the present disclosure may be implemented by a computer program, software, firmware, hardware, or a combination thereof, executable by one or more of processors 2011, 2021.

MEMs 2012 and 2022 may be of any type suitable for the local technological environment, including semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable as non-limiting examples. Can be implemented using any suitable data storage technology, such as memory.

Processors 2011 and 2021 may be of any type suitable to the local technological environment, including one or more of a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor DSP, and a processor based on a multicore processor architecture. may be included as a non-limiting example.

Additionally, the present disclosure may also provide a carrier containing a computer program as described above, where the carrier is one of an electronic signal, an optical signal, a wireless signal, or a computer readable storage medium. The computer readable storage medium may be, for example, an optical compact disc, random access memory (RAM), read only memory (ROM), flash memory, magnetic tape, CD-ROM, DVD, Blu-ray disc, etc. It can be an electronic memory device such as.

The techniques described herein may be implemented by a variety of means, such that devices implementing one or more functions of the corresponding device described in one embodiment are not the only means of the prior art; However, it is also a means for performing one or more functions of the corresponding device described in the embodiments, a separate means for each separate function, or a means for performing two or more functions. may include means that may be configured to. For example, these techniques may be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. With firmware or software, implementation can be through modules (eg, procedures, functions, and so on) that perform the functions described herein.

Example embodiments herein have been described above with reference to block diagrams and flowchart illustrations of methods and apparatus. It will be understood that each block in the block diagrams and flowchart illustrations, and combinations of blocks in the block diagrams and flowchart illustrations, may be implemented by a variety of means, including computer program instructions. These computer program instructions are implemented in flowchart blocks to produce a machine such that the instructions executed on a computer or other programmable data processing device create a means for performing specified functions. , a general purpose computer, special purpose computer, or other programmable data processing device.

Although this specification contains many specific implementation details, these are not intended as limitations on the scope or what may be claimed of any implementation, but rather as illustrations of features that may be specific to a particular embodiment of a particular implementation. should be interpreted as Certain features that are described herein in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features are described above as operating in a particular combination and may initially be claimed as such, one or more features from the claimed combination may be excised from the combination. The claimed combination may then be directed to subcombinations or variations of subcombinations.

It will be apparent to those skilled in the art that as technology advances, the concepts of the invention may be implemented in a variety of ways. The embodiments described above are given to illustrate rather than limit the present disclosure, and those skilled in the art will readily understand that modifications and variations may be resorted to without departing from the spirit and scope of the present disclosure. Can be done. Such modifications and variations are considered to be within the scope of this disclosure and the appended claims. The scope of protection of this disclosure is defined by the appended claims.

Claims (8)

means for receiving configuration information regarding user equipment (UE) specific bandwidth from a base station;
means for generating a first sequence for a Channel State Information Reference Signal (CSI-RS);
the first sequence is mapped into a resource for the CSI-RS;
the resource is configured within the UE-specific bandwidth;
the UE-specific bandwidth is a portion of the cell-specific bandwidth in the cell;
the first sequence has a plurality of elements, the plurality of elements has a first set of indices;
The first set of indices corresponds to a second set of indices having a plurality of first positions within the resource, and each index in the second set of indices is relative to a cell-specific position in the frequency domain. is defined as
the cell-specific location is common to each UE within the cell;
comprising means configured to receive the CSI-RS at the plurality of first locations;
U.E. the UE-specific bandwidth may overlap in the frequency domain with UE-specific bandwidths configured for other UEs;
UE according to claim 1. scheduled within said UE-specific bandwidth;
UE according to claim 1. a plurality of UEs are located within the cell, each of the plurality of UEs within the cell having a different UE-specific bandwidth;
UE according to claim 1. means for transmitting configuration information regarding UE-specific bandwidth to user equipment (UE);
means for generating a first sequence for a Channel State Information Reference Signal (CSI-RS);
the first sequence is mapped into a resource for the CSI-RS;
the resource is configured within the UE-specific bandwidth;
the UE-specific bandwidth is a portion of the cell-specific bandwidth in the cell;
the first sequence has a plurality of elements, the plurality of elements has a first set of indices;
The first set of indexes corresponds to a second set of indexes having a plurality of first positions within the resource, and each index in the second set of indexes is relative to a cell-specific position in the frequency domain. is defined as
the cell-specific location is common to each UE within the cell;
comprising means configured to transmit the CSI-RS at the plurality of first locations;
base station. the UE-specific bandwidth may overlap in the frequency domain with UE-specific bandwidths configured for other UEs;
The base station according to claim 5 . further comprising means for scheduling the UE within the UE-specific bandwidth;
The base station according to claim 5 . a plurality of UEs are located within the cell, each of the plurality of UEs within the cell having a different UE-specific bandwidth;
The base station according to claim 5 .

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