JP7215634B2 - User Equipment and Base Station - Google Patents

Description

TECHNICAL FIELD 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 wireless communication systems.

The new radio access system, also called NR system or network, is the next generation communication system. At the Radio Access Network (RAN) #71 meeting for the 3rd Generation Partnership Project (3GPP) working group, the study of NR systems was approved. NR Systems considers frequencies up to 100 GHz with the aim of a single technical framework addressing all usage scenarios, requirements and deployment scenarios defined in Technical Report TR 38.913, which includes extended mobile Requirements include broadband, large-scale machine-type communications, ultra-reliable and low-latency communications.

Initial work on this research item should assign high priority to gaining a common understanding of what is needed with respect to the structure and architecture of radio protocols, and focus on progress in the following areas:
- Basic physical layer signal structure for new RATs - OFDM-based waveforms, non-orthogonal waveforms and potential support for multi-access - FFS: other waveforms if they show reasonable gain - Basic frame structure - Channels Coding method

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

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

Dynamic/flexible bandwidth allocation means that dynamic/flexible and UE-specific bandwidth allocation are supported in 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 generate a shared RS for the UE. It is impossible to generate a sequence. On the other hand, RS patterns can also be configurable (e.g., configurable density in the time/or frequency domain), so legacy RS sequences can meet the requirements for different patterns, especially for multi-user scheduling. can't

In the present disclosure, new solutions for transmitting and receiving reference signals in wireless communication systems are provided to alleviate or at least alleviate some of the problems in the prior art.

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

According to a second aspect of the present disclosure, a method of reference signal reception in a wireless communication system is provided. The 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; obtaining an initial reference signal sequence for the terminal 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 comprises 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 terminals each assigned their own reference signal transmission configuration based on a network-side frequency range configuration. be. A sequence and information transmission module is configured to transmit the common reference signal sequence and sequence configuration information to a terminal, the sequence configuration information obtaining an initial reference signal sequence transmitted to the terminal. indicates the parameters that can be

According to a fourth aspect of the present disclosure, an apparatus is provided for receiving a reference signal in a wireless communication system. The apparatus comprises 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 sent from a network side and sequence configuration information indicating parameters for obtaining an initial reference signal sequence sent to the terminal device. be done. A sequence acquisition module is configured to acquire the initial reference signal sequence for the terminal 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, said computer program code, when executed, within a method according to any embodiment of the first aspect. is configured to cause the device to perform the operations of

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

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

Embodiments of the present disclosure propose a low-complexity reference signal sequence solution for wireless communication systems (especially new radio access systems) with dynamic bandwidth allocation and/or configurable reference signal patterns. The common reference signal sequence is generated and shared by at least some terminals regardless of 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. Moreover, the terminal only needs to generate a small number (e.g., only one) of reference signal sequences for different band allocations and/or RS pattern configurations, which implies a less complex solution. .

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

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 potential problems associated with configured RS patterns in NR systems.

FIG. 4 schematically shows a flowchart of a method for reference signal transmission according to an exemplary embodiment of the present disclosure;

FIG. 5 schematically shows common RS sequences and RS sequences for respective UEs with different frequency band assignments, according to exemplary embodiments of the present disclosure.

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

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

FIG. 8 schematically illustrates generation of exemplary common RS sequences using fixed indices, according to yet further embodiments of the present disclosure.

FIG. 9 schematically illustrates an exemplary common RS sequence for UEs with configurable RS patterns according to still further embodiments of the present disclosure.

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

FIG. 11 schematically shows common RS sequences and RS sequences for respective UEs with different RS configurations in the time domain, according to another exemplary embodiment of the present disclosure.

FIG. 12 schematically shows 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 within an RS sequence according to embodiments of the present disclosure. FIG. 14 schematically illustrates different variable modes of modulation symbols within an RS sequence according to embodiments of the present disclosure. FIG. 15 schematically illustrates different variable modes of modulation symbols within an RS sequence according to embodiments of the present disclosure.

FIG. 16A schematically illustrates generating a common RS sequence for symbols with different densities, according to one embodiment of the present disclosure. FIG. 16B schematically illustrates generating common RS sequences for symbols with different densities, according to one embodiment of the present disclosure.

FIG. 17 schematically illustrates a flowchart of a method for reference signal reception according to one embodiment of the present disclosure;

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

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

FIG. 20 illustrates apparatus 2010, which can be embodied as or included in a serving node such as a base station in a wireless network, and terminal equipment such as described herein as being like a UE. Also shown is a simplified block diagram of an apparatus 2020 that may be embodied in 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 should be understood that these embodiments are presented only 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. .

In the accompanying drawings, various embodiments of the present disclosure are illustrated in block diagrams, flow diagrams, and other diagrams. Each block in a flowchart or blocks may represent a module, program, or portion of code containing one or more executable instructions for performing a particular logical function; indicated by a dotted line. Moreover, although these blocks are shown in a specific order for performing method steps, in practice they do not necessarily have to be executed in the exact order shown. For example, they may be performed in reverse order or concurrently, depending on the nature of their respective actions. Each block in the block diagrams and/or flowcharts, and combinations thereof, may be implemented by dedicated hardware-based systems or combinations of dedicated hardware and computer instructions to perform the specified functions/acts. obtain.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the/said [elements, devices, components, means, steps, etc.]" are expressly intended to refer to at least one instance of said element, device, component, means, unit, etc. and should be construed without excluding a plurality of such devices, components, means, units, steps, etc., unless expressly stated otherwise. Moreover, the indefinite articles "a/an" as used herein do not exclude a plurality of such steps, units, modules, devices, objects, and the like.

Furthermore, in the context of this disclosure, User Equipment (UE) may refer to a terminal, mobile terminal (MT), subscriber station, cellular subscriber station, mobile station (MS), or access terminal. (AT: Access Terminal) and may include some or all of the functionality of a UE, terminal, MT, SS, mobile subscriber station, MS, or AT. Furthermore, in the context of this disclosure, the term "BS" may be used to refer to, for example, a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a gNB (NodeB in NR), a Radio Header (RH) , a Remote Radio Head (RRH), a relay, or a low power node such as a femto, pico, or the like.

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

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 CSI-RS generation in LTE, the reference signal sequence

is defined by

where _ns is the slot number in the radio frame,

is the OFDM symbol number in the slot. c(i) is a pseudo-random number sequence generated by a pseudo-random number sequence generator, initialized as follows:

The following is prepended to each OFDM symbol.

and where the quantity

is not composed by higher layers, 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 subframes configured for CSI reference signal transmission, the reference signal sequence

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

shall be mapped to

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

The index for CSI-RS sequence generation is known to the UE, N _RB ^{max, DL} is fixed at 110, N _RB ^DL is obtained from Physical Broadcast CHannel (PBCH), CSI-RS 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, as shown in FIG. The sequence is fixed. Therefore, for the same cell ID, the CSI-RS sequence is common for all UEs in the cell.

However, the situation would be different in an NR system. As mentioned above, dynamic/flexible bandwidth allocation is supported in the NR system, so the UE does not know the total system bandwidth on the network side. Furthermore, different UEs may require different reference signal sequences because 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 Figure 2, there are three different UEs, namely UE1, UE2 and UE3, which are located in the same cell but configured with UE-specific frequency bands for scheduling/measurement purposes, Each of them is only a fraction of the total system bandwidth set on the network side. As shown in FIG. 2, the frequency bands of different UEs may be separated and may overlap partially or completely. From the UE's point of view, the bandwidth allocation should be transparent as its total bandwidth depends on the RF capabilities and it is not essential to know the system bandwidth on the network side.

In such cases, RS configuration with dynamic band allocation may cause some problems. For example, for cell or beam specific RS, it shall be common or shared by a group of UEs, such as RS for CSI measurement. Moreover, considering multi-user MIMO scheduling, the demodulation RS should also be unified for orthogonally co-scheduling. Even for different sequences of RSs for quasi-orthogonal or inter-/intra-cell interference management, the RS sequences should be able to be known to other UEs for advanced interference cancellation. In such a case, RS configuration with dynamic band allocation would not enable RS sharing, but would be a problem.

Furthermore, in NR systems, UEs can be configured with UE-specific RS patterns (eg, UE-specific RS densities) in the time/frequency domain. In such cases, sharing a common RS with existing RS generation solutions is also not possible. However, common RS generation can also be beneficial in many cases, especially when RS patterns are dynamically changed, as the UE can extract the required RS from the common sequence. Furthermore, 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 Y ₁ and Y ₂ , which are respectively denoted as follows.

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 for different RS patterns, especially multi-user scheduling.

In view of the above, this disclosure proposes a common RS sequence design solution that is independent of UE bandwidth or RS pattern configuration. Common RS sequence design allows groups of UEs with their own RS transmission configurations to share common RS sequences, such as their RSs for measurement and multi-use scheduling. Moreover, since RSs from interfering cells are easier to acquire, 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 described with reference to the accompanying drawings. However, it should be noted that these descriptions are for illustrative purposes only and the present disclosure is not so limited.

Referring first to FIG. 4, it schematically shows 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, eg, a BS, Node B (NodeB or NB).

As shown in FIG. 4, first, at step 401, a common reference signal sequence is generated based on a network-side frequency range configuration, the common reference signals each having their own reference signal transmission configuration assigned at least It can be shared by several terminals.

In one embodiment of the present disclosure, a common reference signal sequence is generated at the network side based on 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, . At least relevant. Furthermore, it can also further relate to the Minimum SubCarrier Space (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 pseudorandom sequence that can be initialized with an initial value C_init by a pseudorandom sequence generator. Initial value C_init is slot index n _s , symbol index

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

where a _i is the _coefficient of each element, i ₌ 0, 1, . Each value N _{link_type} that can be selected and corresponds to the subcarrier spacing is a link type parameter indicating that the initial value is downlink, uplink, or sidelink. Note that for at least some of the terminals, they are assigned the same ^UID , so they can share the generated RS sequence.

In one embodiment of the present disclosure, the following table may be used to illustrate the subcarrier spacing configuration.
Table 1 Subcarrier interval configuration example

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

For downlink or uplink, the RS sequences are symmetrical 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. Each RS sequence starts from a different index of the common RS sequence and has a different length. As shown, the RS sequence for UE1 may start at i_start_1 (R_3 for common RS sequence) and end at i_end_1 (R_10 for common RS sequence). The RS sequence of UE2 may start at i_start_2 (R_i in common RS sequence) and end at i_end_2 (R_M-2 in common RS sequence). The RS sequence of UE3 may start at i_start_3 (R_2 in common RS sequence) and end at i_end_3 (R_i+2 in common RS sequence). In other words, the RS sequences for each UE would correspond to their own assigned frequency band. Here, the starting 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 sent to the terminal device, the sequence configuration information indicating parameters by which the initial reference signal sequence sent to the terminal device can be obtained. .

A common RS sequence may be sent to at least some terminals, each terminal receiving the RS sequence for itself, respectively, on their own assigned band. However, the terminal also needs to know the initial modulation symbols of the RS sequence (ie the initial RS sequence without channel), for example to perform channel measurements or joint scheduling. By this means, it is possible to transmit sequence configuration information indicating parameters with which the initial reference signal sequence transmitted to the terminal device can be acquired to the terminal device as well. Parameters carried within the sequence configuration information allow the terminal 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, the sequence configuration information may be sent to the terminal 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 is positioned in the common reference signal sequence. Sequence position information may include any of the following:
1) The start index and end index of the reference signal sequence for the terminal, ie i_start_ue and i_end_ue.
2) The start index and length of the reference signal sequence for the terminal, ie i_start_ue and m_ue.
3) End index and length of the reference signal sequence for the terminal, ie i_end_ue and m_ue.

Furthermore, it can be seen that unlike the RS generation solution in LTE, the RS sequence index for the terminal does not correspond to the frequency band index. In such a case, it is also possible to transmit the 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 transmit offset values for fixed frequency locations. In this way, the terminal also knows 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, it is also possible to send the sequence configuration information implicitly. In other words, sequence configuration information can be implied from other parameters. Examples of these parameters include, but are not limited to, the boundary/length of the frequency band assigned to the terminal, the terminal's frequency band configuration, and the terminal's sequence generation initial values.

As mentioned above, the RS sequence for a terminal device corresponds to its own assigned bandwidth, so the boundary/length of the frequency band assigned to the terminal device implicitly defines the sequence configuration information. can be used to indicate Furthermore, if the terminal's band is selected from a group of predetermined bands with a predetermined indication value, the frequency band configuration causes the terminal to learn the assigned frequency band from the predetermined value, and thus the sequence configuration information. can be obtained. Moreover, it is also possible to send the terminal a sequence initialization value C_init_ue from which the terminal 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 RS sequences for different terminals the same at the same frequency or time position.

Note that while the present disclosure has been described using embodiments generated on the network side based on system bandwidth, the present disclosure is not so limited. 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, rather than the entire system bandwidth. It should be appreciated that different serving nodes may be assigned different frequency bandwidths, in which case the network may also generate a common RS sequence corresponding to the assigned frequency bandwidth.

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

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

For each UE, the index idx_rs for RS generation may be indicated to the UE, and the offset value k for idx_rs may also be indicated to the UE. In such case, the UE may determine the starting index of its RS sequence, eg, as idx_rs1=idx_rs+k. Alternatively, independent of idx_rs, the starting index idx_b1 for band/numerology allocation for the UE can be indicated to the UE. RS sequences for two different frequency range settings can be obtained from a common RS sequence generated from idx_rs. RS sequence parameters (eg, for serving and neighbor 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, different frequency range configurations may have at least one of different subcarrier spacing configurations and different cyclic prefix configurations.

Embodiments of the present disclosure may use fixed indices for RS sequence generation for different numerologies. The index may be detected by the UE, eg, by synchronization signals. In other words, for numerology in different numerology configurations, a common reference signal sequence can be generated based on a frequency range covering all possible frequency ranges of numerology. Also, a fixed index and an offset value for the fixed index can be used to indicate the sequence configuration information.

FIG. 7 is a diagram illustrating generation of an exemplary common RS sequence using fixed indices, 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 based on fixed indices, i. or 3 can be used. That is, a common RS sequence generation is generated based on a frequency range covering all possible frequency ranges of numerology, and fixed index and offset values 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 exemplary common RS sequence generation with fixed indices according to another embodiment of the disclosure. This solution is substantially similar to that 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 position.

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

Although the present disclosure is described below primarily with reference to dynamic bandwidth allocation, the present disclosure is not so limited. 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 was generated further based on the total set of resource elements used for RS transmission in different reference signal configurations.

As shown in FIG. 9, the RS patterns are nested in the time-frequency domain, and if configurable RS patterns are supported in the NR system, various RS patterns, with different offsets, with different densities, with different transmissions / without, etc., as shown in the right diagram in FIG. 9 . In such a case, the entire set of resource elements used for RS transmission in different RS configurations can be obtained, as shown in the left diagram of FIG. You can choose from the entire set. A common RS sequence can then be generated further based on the entire set of resource elements used for RS transmissions in 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, using a common RS sequence generated based on the entire set of resource elements used for RS transmissions in different reference signal pattern configurations, 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 shows common RS sequences and RS sequences for respective UEs with different RS densities, according to an embodiment 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 signaled to the UE. For different density configurations, the UE can extract the required sequence from the common sequence R_i. For example, for a UE with a density of 1, the sequence is R_i, i=0, 1, .

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

Similarly, for different SCS configurations, the UE can also extract the required sequences from 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 a UE with density 1/K or SCS K*k0, the sequence can be expressed as:

where i_start is the start index of the sequence, i_end is the end index of the sequence, K is the density parameter (K=2 for 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, RS sequences may be generated with the same or 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 is t0 (e.g. maximum density ). The number of PRBs (relative to SCS k0) can be denoted by N, the length in one symbol over the entire bandwidth can be denoted by L (eg, L=N*d0), and the maximum The length can be represented by M (eg M=L*t0). A common sequence is R_i, i=0, 1, . . . , M−1. For UEs with different configurations, it can extract the required sequence 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, also as shown in FIG. For UEs configured with different time densities ti, their RS sequences can be extracted from the RS sequence group, as shown in FIG. 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. 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 within the common reference signal sequence vary by either a predetermined number of subcarriers in the frequency domain and a predetermined number of symbols in the time domain.

As shown in Figure 13, the modulation symbols in 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 may differ 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. That is, the modulation symbols within a given number of symbols will be the same, but may be different from other given number of symbols.

Furthermore, the modulation symbols within the common RS sequence can also vary by time-frequency block, as shown in FIG. That is, within the same time-frequency block, the modulation symbols will be the same, but from other time-frequency blocks will be different. 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.

Additionally, the density of one RS in different symbols can 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 the first symbol containing the 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 in the same frequency location, or multiplied by the frequency offset (complex). 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. A third option is to initialize the RS sequence for each symbol.

In NR systems, Phase Tracking RS (PT-RS) is introduced, which is used to track phase noise or frequency offset and is a reference signal agreed upon at the RAN1#87 meeting. According to the agreement in the RAN1#87 meeting, the density of PT-RSs in the frequency domain can be quite generous. In such cases, a sequence of PT-RSs can be generated based on previous DMRSs at the same frequency locations. That is, the PT-RS may be equal to 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, in which case the sequence setting information can be transmitted to the terminal device.

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

Figure 17 further schematically illustrates a flow chart of a method for reference signal reception according to an exemplary embodiment of the present disclosure. Method 1700 can be implemented at a terminal device, eg, a UE, or other similar terminal device.

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

In another embodiment of the present disclosure, the sequence configuration information is, for example, any of the boundary/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 including.

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

Accordingly, embodiments of the present disclosure propose a low-complexity reference signal sequence solution for wireless communication systems (especially 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 terminals. 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, the terminal only needs to generate a small number (e.g., only one) of common reference signal sequences for different band allocations and/or RS pattern configurations, which is a less complex solution. means policy.

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

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

As shown in FIG. 18, apparatus 1800 may include reference signal generation module 1801 and 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 terminals each assigned their own reference signal transmission configuration based on a network side frequency range configuration. obtain. Sequence and information transmission module 1802 is configured to transmit a common reference signal sequence and sequence configuration information to terminals, the sequence configuration information for obtaining the initial reference signal sequences transmitted to the terminals. Indicates parameters.

In one embodiment of the present disclosure, the sequence configuration information may include sequence position information indicating the positions where the reference signal sequences for the terminals are positioned in the common reference signal sequences.

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

In a further embodiment of the present disclosure, the sequence configuration information is indicated by any of the boundary/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 yet further embodiments of the present disclosure, the network-side frequency range configuration may include either the system bandwidth and the frequency bands set for the node serving the terminal.

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, for different frequency range configurations, a common reference signal sequence based on frequency ranges covering all possible frequency ranges of the different frequency range configurations. may be further configured to 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, 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 in different reference signal configurations.

In still further embodiments of the present disclosure, the modulation symbols in the common reference signal sequence vary by either time-frequency blocks, 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, modulation symbols within a reference signal sequence within a symbol may be generated based on modulation symbols within a 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 the previous symbol.

FIG. 19 further schematically shows a block diagram of an apparatus 1900 for receiving reference signals in a wireless communication system according to one embodiment of the disclosure. Apparatus 1900 may be implemented in a terminal device, eg, a UE, or other similar terminal device.

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

In one embodiment of the present disclosure, the sequence acquisition module 1902 can be further configured to acquire an initial reference signal sequence for the terminal based on the terminal's sequence configuration information and the reference signal pattern.

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

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

Those skilled in the art will appreciate that the foregoing examples are for illustration only and are 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.

Moreover, 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 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 compatible or interpretable high-level and/or low-level programming language. According to embodiments, the computer-executable instructions may be configured to cause the apparatus 1800 and 1900, using at least one processor, to perform operations according to the methods described with reference to at least FIGS. 4-17, respectively.

FIG. 20 is embodied as 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 the UE described herein. It also shows a simplified block diagram of an apparatus 2020 that may be either or be included therein.

Apparatus 2010 comprises at least one processor 2011 , such as a data processor (DP), and at least one memory (MEMory) 2012 coupled to processor 2011 . Apparatus 2010 further includes transmitter TX and receiver RX 2013 coupled to processor 2011 and 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 an associated processor 2011, enable apparatus 2010 to operate in accordance with embodiments of the present disclosure, such as method 400. A combination of at least one processor 2011 and at least one MEM 2012 can form processing means 2015 adapted to implement various embodiments of the present disclosure.

Apparatus 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 . MEM 2022 stores PROG 2024 . PROG 2024 may include instructions that, when executed on an associated processor 2021, enable apparatus 2020 to operate, eg, perform method 1700, in accordance with embodiments of the present disclosure. A combination of at least one processor 2021 and at least one MEM 2022 can form processing means 2025 adapted to implement various embodiments of the present disclosure.

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

MEMs 2012 and 2022 can 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. It can be implemented using any suitable data storage technology such as memory.

Processors 2011 and 2021 may be of any type suitable for the local technical environment, including one or more of general purpose computers, special purpose computers, microprocessors, digital signal processor DSPs and processors based on multi-core processor architectures. included as non-limiting examples.

Furthermore, the present disclosure can also provide a carrier containing a computer program as described above, the carrier being one of an electronic signal, optical signal, radio signal, or computer readable storage medium. Computer-readable storage media are, for example, optical compact discs, or random access memory (RAM), read only memory (ROM), flash memory, magnetic tape, CD-ROM, DVD, Blu-ray disc, etc. can be an electronic memory device such as a

The techniques described herein may be implemented by a variety of means, such that an apparatus that performs one or more functions of the corresponding apparatus described in one embodiment is not solely by means of the prior art; However, it is also a means for implementing one or more functions of the corresponding apparatus described in the embodiments, and separate means for each separate function, or means for performing more than one function. means that can 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 any combination thereof. With firmware or software, implementation can be through modules (eg, procedures, functions, and so on) that perform the functions described herein.

Exemplary 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 of the block diagrams and flowchart illustrations, and combinations of blocks in the block diagrams and flowchart illustrations, respectively, can be implemented by various means including computer program instructions. These computer program instructions are represented in flow chart blocks to manufacture a machine such that the instructions executing on a computer or other programmable data processing apparatus create means for performing the specified functions. , general purpose computer, special purpose computer or other programmable data processing apparatus.

Although this specification contains many specific implementation details, these are not intended as limitations on the scope of any implementation or what may be claimed, but rather a description of features that may be specific to particular embodiments of particular implementations. should be interpreted as Certain features that are described in this specification 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. Further, although features are described above as working in particular combinations and may initially be claimed in their own right, one or more features from the claimed combination may be cut from the combination. And the claimed combinations may be directed to subcombinations or variations of subcombinations.

It will be apparent to those skilled in the art that as technology advances, the inventive concept can be implemented in various ways. The above-described embodiments are given to illustrate rather than limit the disclosure, and are susceptible to modifications and variations without departing from the spirit and scope of the disclosure, as will be readily appreciated by those skilled in the art. can be done. Such modifications and variations are considered within the scope of the present disclosure and appended claims. The protection scope of the disclosure is defined by the appended claims.

Claims (10)

means for generating a first sequence for a Channel State Information Reference Signal (CSI-RS);
The first sequence is mapped within resources for the CSI-RS;
The resource is set within a user equipment (UE) specific bandwidth,
the UE-specific bandwidth is a portion of a cell-specific bandwidth in a cell;
the first sequence having a plurality of elements, the plurality of elements having a first index set;
The first index set corresponds to a second index set of a plurality of second positions within the resource, each index in the second index set being relative to a cell-specific position in the frequency domain. defined as
the cell-specific location is common to each UE in the cell;
means configured to receive the CSI-RS at the plurality of second locations;
U.E. further comprising means for receiving information corresponding to the starting position and width in the frequency domain of the UE-specific bandwidth;
UE according to claim 1. 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 the UE-specific bandwidth;
UE according to claim 1. a plurality of UEs 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 generating a first sequence for a Channel State Information Reference Signal (CSI-RS);
The first sequence is mapped within resources for the CSI-RS;
The resource is set within a user equipment (UE) specific bandwidth,
the UE-specific bandwidth is a portion of a cell-specific bandwidth in a cell;
the first sequence having a plurality of elements, the plurality of elements having a first index set;
The first index set corresponds to a second index set of a plurality of second positions within the resource, each index in the second index set being relative to a cell-specific position in the frequency domain. defined as
the cell-specific location is common to each UE in the cell;
means configured to transmit the CSI-RS at the plurality of second locations;
base station. further comprising means for transmitting information corresponding to the starting position and width in the frequency domain of the UE-specific bandwidth;
A base station according to claim 6. The UE-specific bandwidth may overlap in the frequency domain with UE-specific bandwidths configured for other UEs.
A base station according to claim 6. further comprising means for scheduling UEs within said UE-specific bandwidth;
A base station according to claim 6. a plurality of UEs located within the cell, each of the plurality of UEs within the cell having a different UE-specific bandwidth;
A base station according to claim 6.

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