WO2017204549A1

WO2017204549A1 - Method and device for mapping between reference signals and multiple access signatures

Info

Publication number: WO2017204549A1
Application number: PCT/KR2017/005392
Authority: WO
Inventors: Chen QIAN; Chenxi HAO; Bin Yu; Jingxing Fu; Qi XIONG
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2016-05-24
Filing date: 2017-05-24
Publication date: 2017-11-30
Also published as: CN107425947A; CN107425947B

Abstract

The present disclosure relates to a pre-5^th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4^th-Generation (4G) communication system such as Long Term Evolution (LTE). The present disclosure provides a method for mapping between a reference signal and a multiple access signature in a wireless communication, comprises determining a multiple access signature corresponding to a reference signal for using an uplink data transmission, based on a mapping relationship between reference signals and multiple access signatures; and communicating by using the multiple access signature.

Description

METHOD AND DEVICE FOR MAPPING BETWEEN REFERENCE SIGNALS AND MULTIPLE ACCESS SIGNATURES

The present disclosure relates generally to a wireless communication technologies. More specifically, the present disclosure relates to a method and a device for mapping between reference signals and multiple access signatures in a multiple access system.

To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a 'Beyond 4G Network' or a 'Post LTE System'.

The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.

In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.

In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.

Accompanying with rapid developments of information industry, particularly increasing requirements coming from mobile Internet and internet of things (IoT), unprecedented challenges have been brought to future mobile communication technologies. For example, based on the report International Telecommunications Union-Radio Communications sector (ITU-R) M.[IMT.BEYOND 2020.TRAFFIC] of ITU, it can be predicted that by 2020, mobile traffic will grow nearly 1000 times compared with year 2010 (fourth generation mobile communication technology (4G) era), number of connected user equipment (UE) will be more than 17 billion. With massive IoT devices gradually penetrate into the mobile communication network, number of connected UEs may be more amazing. In response to this unprecedented challenge, communications industry and academia have launched a wide range of 5G research, for 2020s. At present, the report ITU-R M.[IMT.VISION] made by ITU has discussed framework and overall objectives of future 5G, and has provided a detailed description for demand outlook, application scenario and each important performance index. In response to new demands in 5G, the report ITU-R M.[IMT.FUTURE TECHNOLOGY TRENDS] made by ITU provides information about technology tendency of 5G, which aims to solve significant problems, such as significant improvement of system throughput, consistent user experience, expansibility, so as to support IoT, delay, energy efficiency, costs, network flexibility, support of emerging services, and flexible spectrum usage, and so on.

To be faced with more diverse service scenarios of 5G, flexible multiple access technologies are needed to support different scenarios and service requirements. For example, facing the multiple service scenarios with massive connections, how to access more users with limited resources becomes a core problem needing to be solved by 5G multiple access technologies. Current 4G long term evolution (LTE) network mainly adopts an Orthogonal Frequency Division Multiplexing (OFDM)-based multiple access technologies, e.g., downlink Orthogonal Frequency Division Multiple Access (OFDMA), and uplink Single-carrier Frequency Division Multiple Access (SC-FDMA). However, it is obvious that current orthogonal-based access mode is difficult to meet the following requirements for 5G: spectral efficiency is increased by 5 to 15 times, and user access number per square kilometer area may reach one million level. By reusing the same resources with multiple users, supported number of user connections may be greatly improved by non-orthogonal Multiple Access (NOMA) technologies. Since users have more chances to access a network, the overall throughput and spectrum efficiency of the network may be improved. In addition, in the face of massive Machine Type Communication (mMTC) scenarios, take into account of cost and realization complexity of a terminal, multiple access technologies with more simple operation and process are necessary to be used. In the face of low-latency or low-power service scenarios, when adopting NOMA technologies, grant-free access and competition may be better implemented, low-latency communication may be achieved, boot time may be reduced, and power consumption of a UE may also be lowered.

At present, the NOMA technologies under research mainly include: Multiple User Shared Access (MUSA), Multiuser Superposition Transmission (MUST), Pattern Division Multiple Access (PDMA), Sparse Code Multiple Access (SCMA), Resource Spread Multiple Access (RSMA), Non-orthogonal Coded Multiple access (NCMA), Non-orthogonal Coded Access (NOCA), Interleave Division Multiple Access (IDMA), Interleave Grid Multiple Access (IGMA), and so on. MUSA, NCMA, NOCA distinguish users with code word. SCMA distinguishes users with codebook. MUST distinguishes users with power. PDMA distinguishes users with different characteristic patterns. IDMA distinguishes users with interleaved sequence. IGMA distinguishes users with interleaved sequence and grid mapping. The detailed contents of IDMA may refer to an early literature: Li Ping, Lihai Liu, Keying Wu and W. K. Leung, “Interleave Division Multiple Access”, IEEE Transactions on Wireless Communication, Vol. 5, No.4, pp. 938-947, Apr. 2006.

Unlike conventional Orthogonal Frequency Division Multiple Access (OFDMA) system, in a new NOMA system (such as IDMA, IGMA, SCMA, PDMA and RSMA, and so on), an evolved Node B (eNB) not only needs to inform a terminal about used demodulation reference signal (DMRS) with control signaling, but also needs to inform the terminal about allocated resources (such as, interleaver, codebook, and/or, grid-mapping pattern). For example, in the IDMA system, suppose there are 8 different interleavers, which may access 8 users simultaneously, at this time, it is necessary to take 3 bits as an index to indicate an interleaver, which is used by each user when accessing the network. Thus, the total additional system overhead is 8*3=24 bits. Similarly, when there are N available resources in a system, the total needed overhead for accessing K users is K log₂N bits. Thus, it can be seen that, when there are massive accessed terminals in a system, significant additional system overhead is needed. Meanwhile, time delay for data transmission is increased, and system throughput is reduced. Subsequently, how to reduce signaling overhead becomes an important factor for promoting revolution of multiple access technologies.

Various embodiments of the present disclosure provides methods and devices for mapping between reference signals and multiple access signatures, so as to reduce signaling overheads.

According to various embodiments, the present disclosure provides a method for mapping between a reference signal and a multiple access signature includes determining a reference signal used by an uplink data transmission, determining multiple access signatures, based on a mapping relationship between reference signals and multiple access signatures, and communicating by using the multiple access signatures.

In one embodiment, preferably, determining the multiple access signatures based on the mapping relationship between reference signals and multiple access signatures includes taking a parameter for generating the reference signal as an index, and determining the corresponding multiple access signatures based on a pre-set mapping rule.

In another embodiment, preferably, when the multiple access signatures are an interleaver, and taking T1 parameters as the index, 1≤T1≤4, determining the corresponding multiple access signatures based on the pre-set mapping rule includes taking a pre-stored mother interleaver as a first-level mother interleaver, generating a next level mother interleaver by taking any unused parameter of the T1 parameters as the index, based on the pre-set mapping rule, until taking the last unused parameter of the T1 parameters as the index to generate an interleaver for multiple access.

In yet another embodiment, preferably, when the multiple access signatures are power, and taking T2 parameters as the index, 1≤T2≤4, determining the corresponding multiple access signatures based on the pre-set mapping rule includes taking a predetermined power reference as a first-level power reference, generating a next level power reference by taking any unused parameter of the T2 parameters as the index, based on the pre-set mapping rule, until generating the power for multiple access by taking the last unused parameter of the T2 parameters as the index.

In yet another embodiment, preferably, when the multiple access signatures are a combination of at least one or two of space resource, bit-level interleaver, symbol-level interleaver, power, non-orthogonal codebook, orthogonal codebook, scramble sequence, or grid-mapping pattern, wherein when taking one parameter of the reference signal as the index, determining the corresponding multiple access signatures by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule includes selecting the corresponding multiple access signatures based on the parameter, wherein when taking two parameters of the reference signal as the index, the method further includes dividing the multiple access signatures into N₁ groups, wherein each group includes N₂ resources, N₁ and N₂ are respectively numbers of a first parameter and a second parameter of the two parameters, wherein determining the corresponding multiple access signatures by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, includes selecting a group of the multiple access signatures based on the first parameter, selecting the used multiple access signatures within the group based on the second parameter; and/or, wherein when taking three parameters of the reference signal as the index, the method further includes: dividing the multiple access signatures into N₁first-layer groups, wherein each first-layer group possesses N_{2 *}N₃ resources; dividing N_{2 *}N₃ resources of each first-layer group into N₂second-layer groups, wherein each second-layer group includes N₃ resources; N₁, N₂and N₃are respectively numbers of a first parameter, a second parameter, a third parameter of the three parameters; wherein mapping to the corresponding multiple access signatures by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, includes: selecting a first-layer group of the multiple access signatures based on the first parameter, selecting a second-layer group of the multiple access signatures based on the second parameter; selecting the used multiple access signatures within a selected second-layer group, based on the third parameter; and/or, wherein when taking four parameters of the reference signal as the index, the method further includes dividing the multiple access signatures into N₁ first-layer groups, wherein each first-layer group includes N₂*N₃*N₄ resources, dividing N₂*N₃*N₄ resources of each first-layer group into N₂ second-layer groups, wherein each second-layer group includes N₃*N₄ resources, dividing N₃*N₄ resources of each second-layer group into N₃ third-layer groups, wherein each third-layer group includes N₄ resources, wherein N₁, N₂, N₃ and N₄ are respectively numbers of a first parameter, a second parameter, a third parameter and a fourth parameter of the four parameters, wherein determining the corresponding multiple access signatures by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, includes selecting a first-layer group of the multiple access signatures based on the first parameter, selecting a second-layer group of the multiple access signatures based on the second parameter, selecting a third-layer group of the multiple access signatures based on the third parameter, selecting the used multiple access signatures within the selected third-layer group based on the fourth parameter.

In yet another embodiment, preferably, when one terminal transmits at least two data flows with the same time-frequency resource, determining the corresponding multiple access signatures by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, includes taking the interleaver for multiple access as the last level mother interleaver, and generating an interleaver used by each data flow by using the index of the data flow, based on the last level mother interleaver and the pre-set mapping rule.

In yet another embodiment, preferably, when one terminal transmits at least two data flows with the same time-frequency resource, determining the corresponding multiple access signatures by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, includes taking the power for multiple access as the last level power reference, generating the power used by each data flow based on the index of the data flow, by using the last level power reference and the pre-set mapping rule.

In yet another embodiment, preferably, in a case where take one parameter of the reference signal as the index, when one terminal transmits at least two data flows with the same time-frequency resource, the method further includes dividing the multiple access signatures into N₁ groups, wherein each group includes N_s resources, N₁ is number of the one parameter, N_s is the maximum number of data flows transmittable by each terminal with the same time-frequency resources, wherein determining the corresponding multiple access signatures, by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, includes selecting a first-layer group of the multiple access signatures based on the first parameter, selecting the multiple access signatures used by each data flow within the selected first-layer group, based on the index of the data flow; and/or, wherein in a case where take two parameters of the reference signal as the index, when one terminal transmits at least two data flows with the same time-frequency resource, the method further includes dividing the multiple access signatures into N₁first-layer groups, wherein each first-layer group includes N₂ * N_s resources, dividing N₂ * N_s resources of each first-layer group into N₂ second-layer groups, wherein each second-layer group includes N_s resources, wherein N_s is the maximum number of data flows transmittable by each terminal with the same time-frequency resources, wherein determining the corresponding multiple access signatures, by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, includes selecting a first-layer group of the multiple access signatures based on the first parameter, selecting a second-layer group of the multiple access signatures based on the second parameter, selecting the multiple access signatures used by each data flow within the selected second-layer group, based on the index of the data flow; and/or, wherein in a case where take three parameters of the reference signal as the index, when one terminal transmits at least two data flows with the same time-frequency resource, the method further includes dividing the multiple access signatures into N₁ first-layer groups, wherein each first-layer group includes N₂*N₃*N_s resources, dividing the N₂*N₃*N_s resources of each first-layer group into N₂ second-layer groups, wherein each second-layer group includes N₃* N_s resources, dividing the N₃*N_s resources of each second-layer group into N₃ third-layer groups, wherein each third-layer group includes N_s resources; N_s is the maximum number of data flows transmittable by each terminal with the same time-frequency resources, wherein determining the corresponding multiple access signatures by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, includes selecting a first-layer group of the multiple access signatures based on the first parameter, selecting a second-layer group of the multiple access signatures based on the second parameter, selecting a third-layer group of the multiple access signatures based on the third parameter, selecting the multiple access signatures used by each data flow within the selected third-layer group, based on the index of the data flow; and/or, wherein in a case where take four parameters of the reference signal as the index, when one terminal transmits at least two data flows with the same time-frequency resource, the method further includes dividing the multiple access signatures into N₁ first-layer groups, wherein each first-layer group includes N₂*N₃*N₄* N_s resources, dividing the N₂*N₃*N₄* N_s resources of each first-layer group into N₂ second-layer groups, wherein each second-layer group includes N₃*N₄* N_s resources, dividing the N₃*N₄* N_s resources of each second-layer group into N₃ third-layer groups, wherein each third-layer group includes N₄* N_s resources, dividing the N₄* N_s resources of each third-layer group into N₄ fourth-layer groups, wherein each fourth-layer group includes N_s resources, N_s is the maximum number of data flows transmittable by each terminal with the same time-frequency resources, wherein determining the corresponding multiple access signatures by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, includes selecting a first-layer group of the multiple access signatures based on the first parameter, selecting a second-layer group of the multiple access signatures based on the second parameter, selecting a third-layer group of the multiple access signatures based on the third parameter, selecting a fourth-level group of the multiple access signatures based on the fourth parameter, selecting the multiple access signatures used by each data flow within the selected fourth-level group, based on the index of the data flow.

In yet another embodiment, preferably, wherein when the multiple access signatures are a combination of a bit-level interleaver and at least one of: a space resource, power, a symbol-level interleaver, a non-orthogonal codebook, an orthogonal codebook, a scramble sequence, or a grid-mapping pattern, determining the corresponding multiple access signatures by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, includes taking some parameters or all the parameters for generating the reference signal as the index, respectively determining an interleaver corresponding to multiple access and other multiple access signatures, based on the pre-set mapping rule.

In yet another embodiment, preferably, when the multiple access signatures are a combination of power and at least one of: a space resource, a bit-level interleaver, a symbol-level interleaver, a non-orthogonal codebook, an orthogonal codebook, a scramble sequence, or a grid-mapping pattern, determining the corresponding multiple access signatures by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, includes taking all the parameters or some parameters for generating the reference signal as the index, respectively determining the power corresponding to multiple access and other multiple access signatures, based on the pre-set mapping rule.

In yet another embodiment, preferably, when a total number of multiple access signatures is less than a total number of reference signals, the method further includes enabling the total number of multiple access signatures to be the same as the total number of reference signals, by way of replication, and dividing the copied multiple access resource signatures into groups.

In yet another embodiment, preferably, when a total number of multiple access signatures is less than a production of a total number of reference signals and a maximum number of transmission flows of a terminal, the method further includes enabling the total number of multiple access signatures to be the same as the product, which is obtained after multiplying the total number of reference signals by the maximum number of transmission flows of the terminal, by way of replication, and dividing the copied multiple access signatures into groups.

In yet another embodiment, preferably, in a grant-free system, the method further includes determining the parameter based on a pre-set rule, by using a selected preamble sequence and a mapping relationship between preamble sequence and parameter for generating the reference signal, wherein the reference signal is used by the uplink data transmission, and number of the parameter is 1 to 4.

In yet another embodiment, preferably, determining the parameter based on the pre-set rule, by using the selected preamble sequence and the mapping relationship between preamble sequence and parameter for generating the reference signal includes when there is one parameter, determining the parameter based on the preamble sequence, when there are two parameters, dividing the preamble sequence into N₁₁first-layer groups; determining the sixth parameter in the two parameters, by using position of the selected preamble sequence in the first-layer groups; determining the fifth parameter in the two parameters, by using the first-layer group of the selected preamble sequence; wherein N₁₁ is number of the fifth parameter; and/or, when there are three parameters, dividing the preamble sequence into N₁₁ first-layer groups, dividing the preamble sequence of each first-layer group into N₂₁ second-layer groups; determining the seventh parameter of the three parameters, by using position of the selected preamble sequence in the second-layer groups; determining the sixth parameter of the three parameters, by using the second-layer group of the selected preamble sequence; determining the fifth parameter of the three parameters, by using the first-layer group of the selected preamble sequence; wherein N₁₁ is number of the fifth parameter, N₂₁ is number of the sixth parameter; and/or, when there are four parameters, dividing the preamble sequence into N₁₁ first-layer groups; dividing the preamble sequence of each first-layer group into N₂₁ second-layer groups; dividing the preamble sequence of each second-layer group into N₃₁ third-layer groups; determining the eighth parameter of the four parameters, by using position of the selected preamble sequence in the third-layer groups; determining the seventh parameter of the four parameters, by using the third-layer group of the selected preamble sequence; determining the sixth parameter of the four parameters, by using the second-layer group of the selected preamble sequence; determining the fifth parameter of the four parameters, by using the first-layer group of the selected preamble sequence; wherein N₁₁,N₂₁, N₃₁ are respectively numbers of the fifth parameter, the sixth parameter, and the seventh parameter.

According to various embodiments, the present disclosure also provides a device for mapping between a reference signal and a multiple access signature, including a reference signal determining module, a mapping module and a transmitting module, wherein the reference signal determining module is to determine a reference signal used by an uplink data transmission, the mapping module is to determine multiple access signatures, based on a mapping relationship between reference signals and multiple access signatures, and the transmitting module is to communicate by using the multiple access signatures.

In yet another embodiment, preferably, wherein the reference signal determining module is further to determine the reference signal used by the uplink data transmission, by using a selected preamble sequence and a pre-set rule.

Based on foregoing technical solutions, it can be seen that by adopting the method for determining a mapping relationship between a DMRS and a resource pool, which is provided by the present disclosure, the eNB and terminal may be enabled to obtain corresponding multiple access signature information with allocated DMRS, so as to avoid additional signaling overhead and transmission delay. In the mapping method of the present disclosure, corresponding multiple access signatures may be dynamically obtained based on generation method of DMRS and application scenario (in a one-to-one mapping, one-to-multiple mapping, or multiple-to-one mapping). Meanwhile, the method of the present disclosure may be applied to a grant-free system, so as to simplify flows and reduce complexity.

FIG.1 is a flowchart illustrating a mapping based on a grant-based system, in accordance with an embodiment of the present disclosure.

FIG.2 is a flowchart illustrating a mapping based on a grant-free system, in accordance with an embodiment of the present disclosure.

FIG.3 is a mapping flowchart illustrating to obtain an interleaver based on root sequence and cyclic shift of a reference signal, in accordance with an embodiment of the present disclosure.

FIG.4 is a block diagram illustrating principle of a sender in the interleave grid multiple access (IGMA) system, in accordance with an embodiment of the present disclosure.

FIG.5 is a mapping flowchart illustrating to obtain an interleaver based on root sequence, cyclic shift, orthogonal cover code (OCC) and comb of a reference signal, in accordance with an embodiment of the present disclosure.

FIG.6 is a schematic diagram illustrating how to map to an interleaver based on number of transmission data flows of a terminal, in accordance with an embodiment of the present disclosure.

FIG.7 is a schematic diagram illustrating structure of a device for mapping between reference signals and multiple access signatures, in accordance with an embodiment of the present disclosure.

To make objectives, technical solutions and advantages of the present disclosure more clear, detailed descriptions of the present disclosure will be provided in the following, accompanying with attached figures and embodiments.

At present, research focus of multiple access technologies is simulation and verification of link and system-level performance. No matter which multiple access technology is adopted by standard in the future, how to reduce system overhead is a non-ignorable problem. In a practical system, a user may use different reference signals to detect and estimate a channel (e.g., Sounding Reference Signal (SRS) and DeModulation Reference Signal (DMRS)), so as to complete demodulation of a received signal. Thus, the present disclosure provides a method for mapping between reference signals and multiple access signatures. Subsequently, an eNB and a terminal may obtain corresponding multiple access signature information with allocated reference signals, so as to reduce signaling overheads. By adopting the mapping method in the present disclosure, corresponding multiple access signatures may be dynamically obtained based on generation method of a reference signal and application scenario (may be in a one-to-one mapping, in a one-to-multiple mapping, or in a multiple-to-one mapping). The technical solution of the present disclosure may be applied to a grant-free system, so as to simplify flows and reduce complexity.

Firstly, take into account of a grant-based system. FIG.1 is a basic flow chart illustrating a mapping method in a grant-based system, in accordance with an embodiment of the present disclosure. As shown in FIG.1, the method may include the following main blocks.

In block 1, an eNB allocates a reference signal for each terminal with a physical downlink control channel (PDCCH).

In block 2: the eNB and the terminal respectively map to corresponding multiple access signatures by using a mapping method in the present disclosure, based on index of allocated reference signal thereof.

In block 3: the terminal transmits the allocated reference signal to the eNB, and the eNB estimates a channel between the terminal and the eNB with the received reference signal.

In block 4: the terminal communicates with the eNB by using the multiple access signatures, based on a predetermined transmission method. The multiple access signature are obtained by the mapping.

The main features of the present disclosure are operations in block 2 to map and obtain corresponding multiple access signatures with allocated reference signal. The operations in block 2 includes as follows.

1) For a system taking an interleaver as multiple access signatures, e.g., interleave division multiple access (IDMA) system, when taking T1 parameters among parameters for generating a reference signal as an index (1≤T1≤4), sender and receiver take a pre-stored mother interleaver as a first-level mother interleaver, and take any unused parameter among T1 parameters as an index to generate a next level mother interleaver, according to a certain rule, and so on, until take the last unused parameter among the T1 parameters as an index to generate an interleaver for multiple access.

2) For a system taking power as multiple access signatures, e.g., uplink power domain non-orthogonal multiple access (NOMA) system, when taking T2 parameters among parameters for generating a reference signal as an index (1≤T2≤4), sender and receiver take a predetermined power reference as a first-level power reference, take any unused parameter among T2 parameters as an index to generate a next level power reference according to a certain rule, and so on, until take the last unused parameter among the T2 parameters as an index to generate a power used for multiple access.

3) When multiple access signatures are a combination of at least one of: space resource, bit-level interleaver, symbol-level interleaver, power, non-orthonogal code book, orthonogal code book, scramble sequence, grid-mapping pattern, e.g., sparse code multiple access (SCMA), resource spread multiple access (RSMA), multiple user shared access (MUSA), pattern division multiple access (PDMA), non-orthogonal coded multiple access (NCMA), non-orthogonal coded access (NOCA), interleave grid multiple access (IGMA), uplink power domain NOMA, uplink multi-user multiple-input multiple-output (MIMO) system, divide the multiple access signature combination into groups of at least one layer, take a parameter for generating the reference signal as an index to select a group category for groups of each layer in sequence, and select a resource combination for multiple access within a group.

4) When the multiple access signatures are a combination of bit-level interleaver and at least one of the following resource: space resource, power, symbol-level interleaver, non-orthogonal code book, orthogonal code book, scramble sequence, grid-mapping pattern, take all the parameters or some parameters for generating a reference signal as an index, respectively determine a corresponding interleaver for multiple access and other multiple access signatures. In one example, the corresponding interleaver (e.g. bit-level interleaver) for multiple access and other multiple access signatures are determined according to a mapping rule. Similarly, when the multiple access signatures are a combination of power and at least one of following resource: space resource, bit-level interleaver, symbol-level interleaver, non-orthogonal code book, orthogonal code book, scramble sequence, grid-mapping pattern, take all the parameters or some parameters for generating a reference signal as an index, respectively determine a corresponding power used for multiple access and other multiple access signatures. In one example, a the corresponding power used for multiple access and other multiple access signatures are determined according to a pre-set mapping rule.

5) When a terminal may operates on multiple transmission flows, on the basis of the mapping modes described with 1), 2), 3), 4), number of data flows of each terminal may be used to map a reference signal to various multiple access signatures.

6) When number of multiple access signatures in a system is less than available number of reference signals, e.g., SCMA, RSMA, MUSA, PDMA, NCMA, NOCA system, an overlapped grouping method (that is, the same multiple access signature may belong to different groups, or one group may include various same multiple access signature) may be used to implement multiple-to-one mapping from reference signal to multiple access signature.

The present disclosure also takes into account of a grant-free system. FIG.2 is a flowchart illustrating a mapping based on a grant-free system, in accordance with an embodiment of the present disclosure. Based on a selected preamble sequence, an eNB and a terminal may obtain a reference signal used when transmitting grant-free uplink data, according to a certain mapping rule. And then, the eNB and the terminal may obtain multiple access signatures used when transmitting uplink data by using the reference signal, according to a certain mapping rule. Subsequently, the terminal transmits the used reference signal to the eNB. The eNB utilizes the received reference signal to perform channel estimation. The terminal then uses the multiple access signatures to communicate with the eNB, according to a predetermined transmission mode. The method for mapping from reference signal to multiple access signature is the same as that in a grant-based system. In addition, main features for mapping from a preamble sequence to a reference signal are to obtain root sequence, cyclic shift, orthogonal cover code (OCC) and comb for generating the reference signal, based on sequence number of the preamble sequence. One-to-one mapping or multiple-to-one mapping may be implemented dynamically, based on number of preamble sequences and available reference signals.

It should be noted that, the multiple access signatures in the present disclosure may include NOMA resources and orthogonal multiple access signatures. That is, the technical solution provided by the present disclosure is not only applicable to a NOMA system, but also applicable to an orthogonal multiple access system. Specifically speaking, in the SCMA system taking codebook as multiple access signatures, when there are few terminals in the system, an orthogonal code book may be allocated for each terminal. At this time, the multiple access signatures used by each terminal may be obtained, by using the mapping method in the present disclosure. In the following embodiments of the present disclosure, descriptions are mainly provided by taking a NOMA system as an example.

Detailed descriptions for a mapping method in a grant-based system are provided in the following, accompanying with embodiment 1 to embodiment 8. Detailed descriptions for a mapping method in a grant-free system are provided with embodiment 9. Hereinafter, an apparatus (e.g. terminal) according to the present disclosure is described as performing the operations of the following embodiments. The apparatus may comprises at least one processor for performing signal generation and mapping operation, and at least one transceiver for performing communications (uplink or downlink).

A communication system includes a downlink (DL) that conveys signals from transmission points such as base stations or eNBs to UEs and an uplink (UL) that conveys signals from UEs to reception points such as eNBs. A UE, also commonly referred to as a terminal or a mobile station, may be fixed or mobile and may be a cellular phone, a personal computer device, or an automated device. An eNB, which is generally a fixed station, may also be referred to as an access point or other equivalent terminology.

Embodiment 1:

In the embodiment, a one-to-one mapping method between a reference signal and an interleaver is described for IDMA. In a practical system, a reference signal generally consists of four various parameters. In one example, the various parameters includes, e.g., at least one of root sequence, cyclic shift, OCC and comb. Here, take into account of a method for mapping to an interleaver with two parameters of a reference signal. The two parameters may be any two parameters of foregoing four parameters. In the embodiment, the two parameters are respectively root sequence and cyclic shift. Specifically, a reference signal sequence

is generated as follows.

u and v are parameters for determining the root sequence

. α represents the cyclic shit. n=0,1,...,T-1 represents the n^th sampling point of a reference signal. T represents length of the reference signal. When two terminals come from different cells, or lengths of resource blocks (RBs) occupied by transmitted data are different, reference signals allocated to these two terminals come from different root sequences. When two terminals come from the same cell, and lengths of occupied RBs are the same, reference signals allocated to these two terminals come from the same root sequence, however the reference signals are generated by have different cyclic shifts.

Here, denote an index of the root sequence of the reference signal with q, q=0,1,…N_q-1. Denote the cyclic shift of the reference signal with α, α=0,1,…,N_α-1. N_q represents number of root sequences. N_α represents number of cyclic shifts. Thus, for a one-to-one mapping, the total number of interleavers may be denoted with N_qN_α.

The mapping mode described in the embodiment is shown in FIG.3. FIG.3 is a mapping flowchart illustrating how to obtain an interleaver, based on root sequence and cyclic shift of a reference signal. The main process performed by the apparatus in the present disclosure is divided into two parts. Firstly, based on a mother interleaver pre-stored in an eNB and a terminal, the apparatus generates a second-level mother interleaver, by taking number q of root sequence of the reference signal as a first parameter, according to a certain rule. And then, based on the obtained second-level mother interleaver, the apparatus generates an interleaver for use in multiple access, by taking the cyclic shift α of the reference signal as a second parameter, according to a certain rule. It should be noted that, during the process for generating the interleaver, usage sequences of root sequence and cyclic shift of a reference signal may be exchanged. That is, firstly based on a mother interleaver pre-stored in an eNB and a terminal, the apparatus generates a second-level mother interleaver with cyclic shift α of a reference signal, according to a certain rule. And then, based on the obtained second-level mother interleaver, the apparatus generatse an interleaver for use in multiple access with number q of root sequence of the reference signal, according to a certain rule. FIG.3 is only described with the first case. In addition, one of root sequence and cyclic shift may be used, so as to generate an interleaver for multiple access.

As shown in FIG.3, the second-level mother interleaver generated with the root sequence index is denoted with the second-

level mother interleaver

0,1,2,…,N_q-1. The interleaver generated with the second-level mother interleaver 0 is denoted with the interleaver 0,N_q,…,(N_α-1)N_q. Similarly, index of the obtained interleaver is denoted with k, k=0,1,…,N_qN_α-1. The mathematical expression of foregoing mapping mode may be denoted with k=q+α×N_q.

It should be noted that, the mathematical expression of the mapping rule here is only an example, and the mapping is not limited to such mathematical expression. In practical applications, the mapping may also be completed based on other methods, by using q and α. One method for generating an interleaver, e.g., index generation mode, will be described in the following. In the index mode, the k^th interleaver is generated by a mother-interleaver π₀, q interleavers π_g1 generated, and α interleavers π_g2 generated in a cascade manner. The mathematical expression is as follows.

To obtain a one-to-one mapping from （q,α） to π_k, the following condition needs to be met, so as to generate an interleaver.

To meet foregoing condition, one selection mode for generating the interleaver is as follows.

Thus,

Descriptions for generating the interleaver π_g are as follows. The l^th bit of an inputted sequence is mapped to l'^th bit of an output sequence through interleaver π_g. Here, the relationship between l and l' is as follows.

S is a spreading factor in the IDMA system. N_b is a bit length after channel encoding (before spreading). The total bit length is S×N_b, l,l'=0,1,…,S×N_b-1. Such rule enables the interleaver π_g to meet the condition

, where |x-y|< N_b. Since k=0,1,…,N_qN_α-1, and k≪N_b, it can be seen that foregoing mapping relationship π_k=π₀·

enables |x-y|< N_b.

1) For a combination （q,α）of any root sequence and cyclic shift, a unique interleaver may be obtained.

2) For different combinations （q,α）of root sequence and cyclic shift, different interleavers may be obtained.

A specific example is as follows: suppose a system has four terminals, each terminal needs to transmit 5 bits, the spreading factor is 3 (the total bit length is 15), and:

then the interleaver generated with index mode is as follows.

It should be noted that, when mapping to an interleaver with one parameter of a reference signal, it is necessary to determine the used interleaver by using the mother interleaver and index of the parameter, according to the method for generating the interleaver in the embodiment.

Embodiment 2:

The first embodiment describes a mapping flow in a system, which takes an interleaver as multiple access signatures. In the embodiment, consider a system taking power as multiple access signatures, such as, uplink power domain NOMA. In such systems, signal reception powers transmitted by various terminals may be different by controlling power, such that the objectives for differentiating users may be achieved. At this time, power control may be implemented, by establishing a mapping relationship with a reference signal.

The embodiment provides a method for mapping to multiple access power, by using two parameters of a reference signal, that is, root sequence and cyclic shift. Firstly, the apparatus in the present disclosure generates a second-level power reference with a first parameter of a reference signal according to a certain rule, by using a power reference predetermined in a system. Subsequently, the apparatus in the present disclosure generates power for use in multiple access with a second parameter of the reference signal according to a certain rule, by using the generated second-level power reference. Here, meanings of the first parameter and second parameter of the reference signal are the same as that in the first embodiment. In the embodiment, the first parameter and the second parameter are respectively the root sequence and the cyclic shift. Specifically, for index q of the root sequence, cyclic shift α, the generated power index is as follows:

q=0,1,2,…,N_q-1. N_q represents the total number of root sequence. α=0,1,2,…,N_α-1. N_α represents the total number of cyclic shift. Denote a unit power offset with P. The power reference predetermined by the system is P₀. And then, the generated receiving power for multiple access is

It should be noted that, the mathematical expression of mapping rule here is only an example, and the mapping is not limited to such mathematical expression. In practical applications, the mapping may also be completed with other methods, by using q and α. In addition, usage sequences of reference signals may be exchanged. That is, take the cyclic shift as the first parameter, and take the root sequence as the second parameter. Meanwhile, the two parameters used may be other parameters of the reference signal, that is, comb and OCC. When mapping to the multiple access power with one parameter of the reference signal, the multiple access power is determined by using a mother power reference and the parameter index, based on the method in the embodiment.

Embodiment 3:

The first embodiment describes a mapping flow in a system, which takes an interleaver as multiple access signatures. The second embodiment describes a mapping flow in a system, which takes receiving power as multiple access signatures. In the embodiment, consider a system taking codebook and/or mode mapping as multiple access signatures, such as SCMA, MUSA, PDMA, NCMA, NOCA and RSMA. In such systems, a resource pool (codebook design and grid-mapping pattern) depends on a more complicated optimization algorithm. Thus, it is difficult to generate the resource pool with a mother resource, by using a simple method. In addition, it should be noted that, the mapping method of the embodiment is also applicable to a system, which takes an interleaver and/or power as multiple access signatures, particularly for the following case. The interleaver and power cannot be generated with a mother interleaver or mother power reference, based on the methods in the first and second embodiments. That is, the embodiment is applicable to a case, in which the multiple access signatures are any of the following: space resource, bit-level interleaver, symbol-level interleaver, power, non-orthogonal codebook, orthogonal codebook, scramble sequence, or grid-mapping pattern.

Specifically, the embodiment provides a method for mapping to multiple access signatures, by using two parameters (that is, take two parameters of a reference signal as an index) of a reference signal, that is, root sequence and cyclic shift. To obtain a one-to-one mapping relationship from a reference signal to a resource pool, divide a resource pool into N_q groups. Each group possesses N_α resources to be selected. Physical meanings of N_q and N_α are the same as that in the first embodiment. That is, N_q represents number of root sequences. N_α represents number of cyclic shifts. It should be noted that, the resource pool may also be divided into N_α groups. Each group possesses N_q resources to be selected. In the embodiment, descriptions are only provided for the first case. First of all, take index q of root sequence as a first parameter (corresponds to the first parameter in claims) to determine a group. And then, take cyclic shift α as a second parameter (corresponds to the second parameter in claims) to determine the selected resource. Thus, as described in the first embodiment, the mapping relationship between the reference signal and the selected resources index is:

It should be noted that, the mathematical expression of the mapping rule here is only an example, and the mapping is not limited to such mathematical expression. In practical applications, mapping may also be completed with q and α according to other methods. Based on such mapping relationship, grouping rule of the resource pool is as follows: for multiple access signature k, the corresponding group index and position in the group are determined with the following method:

group index: k mod N_q;

position in the group:

In the SCMA system shown in Table 1, there are 6 available codebooks. To establish a one-to-one mapping relationship between the 6 codebooks and reference signals, consider the resource grouping shown in Table 2 based on root sequence index and cyclic shift of a reference signal. Suppose number of root sequences N_q=2, number of cyclic shifts N_α=3, as shown in Table 2,

positions

0, 1, 2 in the 0^th group respectively correspond to

numbers

0, 2, 4 of codebooks.

Positions

0, 1, 2 in the first group respectively correspond to numbers 1, 3, 5 of codebooks. When the root sequence of a reference signal is 0, cyclic shift of the reference signal is 2, the index of the multiple access signature used is 4.

In the embodiment, usage sequences of reference signals may be exchanged. That is, take the cyclic shift as the first parameter, and take the root sequence as the second parameter. Meanwhile, the two parameters used may be other parameters of the reference signal, that is, comb and OCC. When mapping to multiple access signatures with one parameter of a reference signal, it is not necessary to divide resources into different groups. The multiple access signatures used may be determined with the index of the parameter.

Embodiment 4:

The embodiment considers a hybrid multiple access system, that is, the multiple access signatures are composed of various kinds of multiple access signatures, which includes at least two of: space resource, bit-level interleaver, symbol-level interleaver, power, non-orthogonal codebook, orthogonal codebook, scramble sequence, or grid-mapping pattern, and so on. For such systems, the embodiment provides a method for mapping to multiple access signatures with two parameters of a reference signal, e.g., root sequence and cyclic shift. Specifically, the method may be applicable to three cases in the following.

In a first case: when combination mode of the multiple access signatures is more complicated, it is difficult to generate the used combination of multiple access signatures with one mother resource. At this time, the method in the third embodiment may be used. Divide the combination of multiple access signatures into different groups, and determine the corresponding combination of multiple access signatures, by using the parameter of the reference signal.

In a second case: when the combination of multiple access signatures includes a bit-level interleaver, such as the IGMA system, the principle block diagram of sender is shown in FIG.4. First of all, data of each user passes through a bit-level interleaver allocated by a system, and then, bits are modulated into a symbol based on a predetermined modulation method. Subsequently, the generated symbol is mapped to time-frequency resources used for transmission, based on grid mapping pattern allocated by the system. In such system, the combination of multiple access signatures includes a first-level (bit-level) interleaver and a grid mapping pattern (symbol-level interleaver). The grid mapping pattern may be generated by zero-padding interleaving. Working principle of zero-padding interleaving is as follows. Suppose length of modulated symbol sequence is L, firstly, by padding zero to the end of the sequence, the total length of zero-padded sequence is 2L (the zero-padded length may be changed based on system configuration). Subsequently, disorganize the sequence by using the symbol-level interleaver with length 2L.

In the IGMA system, the bit-level interleaver and symbol-level interleaver may be respectively generated. That is, the bit-level interleaver may be generated by using the root sequence index and cyclic shift of a reference signal, according to the method in the first embodiment. Subsequently, generate the symbol-level interleaver with the same method. Specifically, firstly generate a second-level mother interleaver based on a mother interleaver π₀ (such mother interleaver is different from the mother interleaver for generating the bit-level interleaver) pre-stored at the sender and receiver, by using the root sequence index q. Subsequently, generate the interleaver for symbol interleaving based on the generated second-level mother interleaver, by using the cyclic shift α. Here, the second-level interleaver and interleaver for symbol interleaving may be generated, by using the index method in the embodiment.

In the IGMA system, the bit-level interleaver may be generated, by using the root sequence index of a reference signal. The symbol-level interleaver may be generated by using the cyclic shift of a reference signal. Specifically, generate the used bit-level interleaver (according to the rule in the first embodiment) based on the mother bit-level interleaver pre-stored in the system, by using the root sequence index q. The index of the bit-level interleaver generated is q. Subsequently, generate the used symbol-level interleaver (according to the rule in the first embodiment) based on the mother symbol-level interleaver pre-stored in the system, by using the cyclic shift α of the reference signal. The index of the generated symbol-level interleaver is α.

Similarly, for another system taking interleaver as one of multiple access signatures, e.g., the combination of multiple access signatures is interleaver and codebook, an interleaver (based on the rule in the first embodiment) and other multiple access signatures (based on the rule in the third embodiment) may be generated in sequence, based on some parameters or all the parameters of a reference signal.

In a third case: when the combination of multiple access signatures includes power, similar to the second case, the power for multiple access may be generated by using the root sequence and cyclic shift of a reference signal, based on the method in the second embodiment. Subsequently, based on the root sequence and cyclic shift of the reference signal, generate other multiple access signatures (e.g., when other multiple access signatures are an interleaver, adopt the rule in the first embodiment; when other multiple access signatures are a codebook, or a combination of complicated multiple access signatures, adopt the rule in the third embodiment).

In addition, generate power for multiple access and other multiple access signatures in sequence, by using some parameters of the reference signal. For example, power P=P₀+qP may be generated, by using root sequence q of a reference signal. P₀ is a power reference. P is a unit power offset. Subsequently, generate other multiple access signatures by using cyclic shift of the reference signal. When other multiple access signatures are an interleaver, the interleaver may be generated by using a mother interleaver stored in a system. When other multiple access signatures are a codebook, or a combination of complicated multiple access signatures, directly select the used resource by using the cyclic shift. Here, usage sequences of reference signals may be exchanged.

In the embodiment, usage sequences of reference signals may be exchanged. Meanwhile, the two parameters used may be other parameters of a reference signal, e.g., comb and OCC. When mapping to a combination of multiple access signatures by using one parameter of a reference signal, for a system in which a combination of multiple access signatures includes interleaver and/or power, generate an interleaver and power for multiple access with the parameter, by using the mother interleaver and/or mother power reference stored in a system, based on the method in the first embodiment and/or the second embodiment. For a system with complicated combination of multiple access signatures, and/or, the combination of multiple access signatures includes codebook, or other multiple access signatures, which cannot be generated with a simple method, based on the rule in the third embodiment, it is not necessary to divide resources into different groups, determine the multiple access signatures used by using the index of the parameter.

Embodiment 5:

Current methods for generating a reference signal are restricted by delay extension of a channel, which cannot allow simultaneous access of massive users in the same frequency. One solution is to improve capacity of reference signals, by introducing comb and/or OCC. As shown in Table 3, for different users allocated with the same cyclic shift and root sequence, reference signals of the different users may be further differentiated by allocating different combs, and/or, OCCs. When introducing two different combs and two different OCCs, the user number accessible by the system will be four times of previous user number.

Here, definitions of the root sequence number q and cyclic shift α of a reference signal are the same as that in the first embodiment and the second embodiment. Furthermore, denote OCC index of a reference signal with n_occ, n_occ=0,1,…N_occ-1. Denote comb of the reference signal with n_comb, n_comb=0,1,…,N_comb-1. N_occ represents the total number of OCC. N_comb represents the total number of comb. Thus, for a one-to-one mapping, the total number of multiple access signatures is N_qN_αN_OCCN_comb.

For the IDMA system, the main mapping process includes four blocks.

In block 1, take number q of root sequence of a reference signal as a first parameter (corresponds to the first parameter in the claims), generate a second-level mother interleaver based on a certain rule, by using a mother interleaver pre-stored in an eNB and a terminal.

In block 2, take cyclic shift α of the reference signal as a second parameter (corresponds to the second parameter in the clams), generate a third-level mother interleaver based on a certain rule, by using the obtained second-level mother interleaver.

In block 3, take index n_OCC of OCC as a third parameter (corresponds to the third parameter in the claims), generate a fourth-level mother interleaver based on a certain rule, by using the obtained third-level mother interleaver.

In block 4, take index n_comb of comb as a fourth parameter (corresponds to the fourth parameter in the claims), generate the used interleaver based on a certain rule, by using the obtained four-level mother inteleaver.

FIG.5 is a mapping flowchart illustrating how to obtain an interleaver, by using root sequence, cyclic shift, OCC and comb of a reference signal, in accordance with an embodiment of the present disclosure. In the example illustrated with FIG.5, the first-level and second-level mapping methods are the same as that in the first embodiment. For a third-level mapping, the fourth-level mother interleaver generated with the third-level mother interleaver 1+N_q is denoted with the fourth-level mother interleaver 1+N_q,1+N_q+N_αN_q,1+N_q+2N_αN_q,1+N_q+(N_OCC-1)N_αN_q. The interleaver generated with the fourth-level mother interlever 1+N_αN_q is denoted with interleaver1+N_q+N_α N_q,1+N_q+N_αN_q+N_OCCN_αN_q,…,1+N_q+N_αN_q+(N_COMB-1)N_OCCN_αN_q. The index of the interlever finally obtained is denoted with k, k=0,1,…,N_qN_αN_OCCN_COMB-1. The mathematical expression of foregoing mapping method may be represented with:

It should be noted that, the mathematical expression of the mapping rule here is only an example. The mapping is not limited to such mathematical expression. In practical applications, mapping may also be completed with foregoing parameters, based on other methods. Furthermore, when generating an interleaver with index method, the interleaver used by terminal k is:

One implementation method is:

Thus:

Selection method for generating interleaver π_g is the same as that in the first embodiment. In addition, usage sequences of the four parameters may be exchanged. When generating an interleaver by using three parameters of a reference signal, the interleaver for multiple access may be obtained with foregoing

blocks

1, 2, 3. Besides, the used three parameters may be any three parameters of the four parameters. When generating an interleaver by using two parameters and one parameter of a reference signal, the method in the first embodiment is used.

For a system taking receiving power as multiple access signatures, such as uplink power domain NOMA, the specific mapping process may include 4 blocks.

In block 1, take number q of root sequence of a reference signal as a first parameter (corresponds to the first parameter in the claims), by using a power reference predetermined in a system, and generate a second-level power reference based on a certain rule.

In block 2, take cyclic shift α of the reference signal as a second parameter (corresponds to the second parameter in the claims), and generate a third-level power reference based on a certain rule, by using the obtained second-level power reference.

In block 3, take index n_OCC of OCC as a third parameter (corresponds to the third parameter in the claims), and generate a fourth-level power reference based on a certain rule, by using the obtained third-level power reference.

In block 4, take index n_comb of comb as a fourth parameter (corresponds to the fourth parameter in the claims), and generate power for multiple access based on a certain rule, by using the obtained fourth-level power reference.

Denote the index of the interleaver finally obtained with k,k=0,1,…,N_qN_αN_OCCN_COMB-1, the mathematical expression of foregoing mapping method may be denoted with:

Denote a unit power offset with P. The power reference predetermined by a system is P₀. And then, the generated receiving power for multiple access is:

It should be noted that, the mathematical expression of the mapping rule here is only an example. Mapping is not limited to such mathematical expression. In practical applications, the mapping may also be completed with foregoing parameters, based on other methods. In addition, usage sequences of the four parameters may be exchanged. When controlling power with three parameters of a reference signal, it is necessary to obtain the power for multiple access with foregoing

blocks

1, 2, 3. The used three parameters may be any three parameters of the four parameters. When controlling power with two parameters and one parameter of a reference signal, the method described in the second embodiment can be adopted.

For a system taking codebook and/or mode mapping as multiple access signatures, such as SCMA, MUSA, PDMA, NCMA, NOCA and RSMA, and/or, the IDMA system in which interleaver cannot be generated with mother resources, and/or, uplink power domain NOMA, in which power cannot be generated with mother resources, that is, for a case in which multiple access signatures are any of : space resource, bit-level interleaver, symbol-level interleaver, power, non-orthogonal codebook, orthogonal codebook, scramble sequence, or grid-mapping pattern, firstly divide multiple access signatures into N_q groups (denote with first-layer groups). Each group possesses N_αN_OCCN_comb resources. Take index q of root sequence for generating a reference signal as a first parameter (corresponds to the first parameter in the claims), so as to select a group.

Subsequently, divide N_αN_OCCN_comb resources of each group into N_α groups (that is, second-layer groups). Each group includes N_OCCN_comb resources. Take cyclic shift α for generating the reference signal as a second parameter (corresponds to the second parameter in the claims), so as to determine a group of the second-layer groups.

And then, divide N_OCCN_comb resources in each group of the second-layer groups into N_OCC groups (that is, third-layer groups). Each group includes N_comb resources. Take OCC index n_OCC for generating the reference signal as a third parameter (corresponds to the third parameter in the claims), and determine a group of the third-layer groups. Finally, select allocated resources from the third-layer groups, by using comb index n_comb (corresponds to the fourth parameter in the claims) for generating the reference signal. The mathematical expression of the resource index may be denoted with:

k=0,1,…,N_qN_αN_OCCN_comb-1. It should be noted that, the mathematical expression of the mapping rule here is only an example. Mapping is not limited to such mathematical expression. In practical applications, the mapping may also be completed with foregoing parameters, by using other methods. Based on such mapping relationship, grouping rule of a resource pool is as follows: for multiple access signature k, group index of each corresponding layer is as follows.

In an example, N_q=2, N_α=4，N_OCC=2，N_comb=2, grouping (mapping) method for 32 multiple access signatures is shown in Table 4. When root sequence, cyclic shift, OCC index and comb index of a reference signal are respectively 0, 1, 0, 1, the index of the used multiple access signature is 2.

For a hybrid multiple access system, that is, in a case where multiple access signatures are a combination of at least two of: space resource, bit-level interleaver, symbol-level interleaver, power, non-orthogonal codebook, orthogonal codebook, scramble sequence, grid-mapping pattern, when combination of multiple access signatures is more complicated and is difficult to be generated with mother resources, the codebook-based grouping method in the multiple access system in the embodiment may be used, so as to complete mapping between reference signal and combination of multiple access signatures.

For a case where combination of multiple access signatures includes interleaver and/or power, the multiple access signatures in the combination of multiple access signatures may be generated in sequence, by using all the parameters or some parameters of a reference signal. For example, in the IGMA system, all the four parameters of a reference signal may be used to generate a bit-level interleaver and a symbol-level interleaver in sequence, based on the method in the embodiment. In addition, the bit-level interleaver may also be generated by using some parameters of a reference signal, such as root sequence index and cyclic shift, based on the method in the first embodiment. Subsequently, the symbol-level interleaver may be generated, by using the OCC index of the reference signal, based on the method in the first embodiment. Here, number of some parameters of the reference signal may be one, two or three, or may be any combination of the four parameters. Meanwhile, during the process for generating each resource in the combination of multiple access signatures, number and combination of reference signals used may be different. That is, for the IGMA system, the bit-level interleaver may be generated (based on the method for generating the interleaver with three parameters in the embodiment), by using root sequence, cyclic shift and OCC. Besides, the symbol-level interleaver may be generated with comb and OCC (based on the method for determining multiple access signatures with two parameters in the first embodiment). It should be noted that, in foregoing hybrid multiple access system, during the process of mapping with three parameters of a reference signal, when generating the combination of multiple access signatures, and/or, each multiple access signature in the combination of multiple access signatures, three parameters may be used at most. In a hybrid multiple access signature system including interleaver and/or power, map to interleaver, and/or, power, and other multiple access signatures (such as codebook) by using some parameters, e.g., two parameters or one parameter. At this time, for a system where combination of multiple access signatures includes interleaver, the mapping rule in the first embodiment may be used. For a system where combination of multiple access signatures includes power, the mapping rule in the second embodiment may be used. For other multiple access signatures, the mapping rule in the third embodiment may be used.

Embodiment 6:

In foregoing five embodiments, a one-to-one mapping solution between reference signal and multiple access signature is considered. When channel state is better, a terminal may transmit multiple data flows with the same time-frequency resources. Each data flow may select different multiple access signatures. At this time, reference signals used by one terminal may correspond to various multiple access signatures. Thus, in the embodiment, a one-to-multiple mapping method between reference signal and multiple access signature is considered. Number of interleavers corresponding to one reference signal is determined by number of data flows, which are transmitted by the terminal.

Take into account that the maximum number of data flows transmittable by each terminal with the same time-frequency resources is N_s. The number of data flows actually transmitted by terminal k is n_k (the number of data flows transmitted by each terminal may be the same, or different). The reference signal is determined by four parameters. The first, second, third, fourth parameters are respectively root sequence, cyclic shift, comb and OCC. The mapping method in the embodiment is an extension of the mapping method in the fifth embodiment. For a system taking an interlever as multiple access signatures, such as IDMA, firstly generate a fifth-level mother interleaver, by using parameters of a reference signal, e.g., root sequence, cyclic shift, comb and OCC. Denote the index of the fifth-level mother interleaver with k. And then, as shown in FIG.6, terminal k generates an interlever used by each data flow based on a certain rule, by using the fifth-level mother interleaver k and index i_k=0,1,…,n_k-1 of the data flow. n_k represents the total number of data flows transmitted by terminal k with the same time-frequency resources. Thus, the mathematical expression of an index of an interleaver used by

data flow of terminal k is: k+i_k×N_qN_αN_OCCN_COMB.

The computation method of k is the same as that in the fifth embodiment. It should be noted that, the mathematical expression of mapping rule here is only an example. The mapping is not limited to such mathematical expression. In practical applications, the mapping may be completed with foregoing parameters, based on other methods. Furthermore, when generating an interleaver with index method, the interleaver used by

data flow of terminal k is:

One implementation method is:

Thus,

The selection method for generating interleaver π_g is the same as that in the first embodiment. It should be noted that, usage sequences of four parameters of a reference signal may be exchanged. When generating an interleaver with three parameters of a reference signal, it is necessary to generate an interleaver used by a terminal, based on

blocks

1, 2, 3 in the fifth embodiment. And then, generate an interleaver used by each data flow, based on an index of a data flow. When generating an interleaver with two parameters or one parameter of a reference signal, it is necessary to generate an interleaver used by a terminal with blocks in the first embodiment. And then, generate an interleaver used by each data flow, by using an index of a data flow. Here, three parameters, two parameters and one parameter of a reference signal may be any combination of four available parameters.

For a system taking power as multiple access signatures, such as uplink power domain NOMA, similar to the fifth embodiment, firstly generate a fifth-level power reference by using parameters of a reference signal, that is, root sequence, cyclic shift, comb and OCC. Denote the index of the fifth-level power reference with k. And then, terminal k generates power corresponding to each data flow based on a certain rule, by using the fifth-level power reference k and index i_k=0,1,…,n_k-1 of the data flow. n_k represents the total number of data flows transmitted by terminal k with the same time-frequency resources. Thus, the mathematical expression of an index of power corresponding to

data flow of terminal k is:

Computation method of k is the same as that in the fourth embodiment. P represents a unit power offset. P₀ represents a power reference predetermined by a system. And then, the generated receiving power for multiple access is:

It should be noted that, the mathematical expression of mapping rule here is only an example. Mapping is not limited to such mathematical expression. In practical applications, mapping may also be achieved with foregoing parameters, based on other methods. Besides, usage sequences of four parameters of a reference signal may be exchanged. When controlling power with three parameters of a reference signal, it is necessary to generate power for multiple access, based on

blocks

1, 2, 3 in the fifth embodiment. And then, generate power used by each data flow, based on index of the data flow. When controlling power with two parameters or one parameter of a reference signal, it is necessary to generate power for multiple access, by executing the blocks in the second embodiment. And then, generate power used by each data flow, by using index of the data flow. Here, the three parameters, two parameters and one parameter of a reference signal may be any combination of four available parameters.

For a system taking codebook and/or mode mapping as multiple access signatures, such as, SCMA, MUSA, PDMA, NCMA, NOCA and RSMA, and/or the IDMA system where interleaver cannot be generated with mother resources, and/or uplink power domain NOMA, where power cannot be generated with mother resources, that is, for a case where multiple access signatures are any of: space resource, bit-level interleaver, symbol-level interleaver, power, non-orthogonal codebook, orthogonal codebook, scramble sequence, grid-mapping pattern, similar to the fifth embodiment, firstly divide multiple access signatures into N_q groups (first-layer groups). Each group possesses N_αN_OCCN_combN_s resources. Select a group based on index q of the root sequence for generating a reference signal. Subsequently, divide N_αN_OCCN_combN_s resources of each group into N_α groups (that is, the second-layer groups). Each group includes N_OCCN_combN_s resources. Determine a group in the second-layer groups, based on cyclic shift α for generating the reference signal. And then, divide N_OCCN_combN_s resources of each group of the second-layer groups into N_OCC groups (that is, the third-layer groups). Each group includes N_combN_s resources. Determine a group of the third-layer groups, based on OCC index n_OCC for generating the reference signal. Subsequently, divide N_combN_s resources of each group of the third-layer groups into N_comb groups (that is, the fourth-layer groups). Each group includes N_s resources. Determine a group of the third-layer groups, by using OCC index n_OCC for generating the reference signal. N_s represents the maximum number of data flows, which are transmittable by each terminal with the same time-frequency resources. Finally, select allocated resources from the fourth-layer groups, based on index i_k=0,1,2,…,n_k-1 of a data flow transmitted by the terminal. n_k represents the total number of data flows, which are transmitted by the terminal with the same time-frequency resources. n_k≤N_s. Thus, the mathematical expression of a mapping rule between index j=0,1,2,…,N_qN_αN_OCCN_combN_s of resource and index of transmission flow, reference signal is:

k=q+α×N_q+n_OCC×N_qN_α+n_comb×N_qN_αN_OCC is the same as that in the third embodiment. It should be noted that, the mathematical expression of mapping rule here is only an example. Mapping is not limited to such mathematical expression. In practical applications, mapping may also be achieved by using foregoing parameters, based on other methods. Based on such mapping relationship, grouping rule of a resource pool is as follows. For multiple access signature j, corresponding group index of each layer is:

In an example, N_q=2, N_α=2, N_OCC=2, N_comb=2 and N_s=2, grouping (mapping) method of 32 multiple access signatures is shown in Table 5. When root sequence, cyclic shift, OCC index, comb index of a reference signal are respectively 0, 1, 0, 1, index of multiple access signature used by a first transmission flow is 10. Index of multiple access signature used by a second transmission flow is 26.

In addition, usage sequences of four parameters of a reference signal may be exchanged. When three parameters of a reference signal are used to select multiple access signatures, it is necessary to divide the multiple access signatures into third-layer groups. And then, select the used multiple access signatures from the third-layer groups, by using index of a data flow. When two parameters or one parameter of a reference signal are used to select the multiple access signatures, it is necessary to divide the multiple access signatures into second-layer groups or first-layer groups. Subsequently, select the used multiple access signatures from groups of the last layer, by using index of a data flow. Here, three parameters, two parameters and one parameter of a reference signal may be any combination of four available parameters.

For a hybrid multiple access system, that is, in a case where the multiple access signatures are a combination of at least two of: space resource, bit-level interleaver, symbol-level interleaver, power, non-orthogonal codebook, orthogonal codebook, scramble sequence, or grid-mapping pattern, when the combination of multiple access signatures is more complicated and is difficult to be generated with mother resources, foregoing grouping method may be used, so as to complete mapping from a reference signal and an index of a data flow to a combination of multiple access signatures. For a case where the combination of multiple access signatures includes interleaver and/or power, such as IGMA, combine an index of a data flow with parameters for generating an interleaver, or parameters for generating power, or parameters for generating other multiple access signatures. And then, determine the combination of multiple access signatures used by each data flow of a user, by using the method in the embodiment.

It should be noted that, since resources used by data flows of different terminals are generated by different mother interleavers, or different power standards, or belong to different groups, resource conflict may not occur among various flows of different terminals. In addition, when number of data flows transmitted by each terminal is different, dynamically generate corresponding multiple access signatures by using the fifth-level mother interleaver (for IDMA and IGMA systems), or by using the fifth power reference (for uplink power domain NOMA), or select corresponding multiple access signatures from the fourth-layer groups (for SCMA, MUSA, PDMA, NCMA, NOCA, RSMA and hybrid multiple access system). For example, in Table 5, when terminal 0 only transmits one data flow, it is only necessary to select multiple access signature 0. When each terminal has one data flow, that is, n₁=n₂=…=1, for IDMA and IGMA systems, the fifth-level interleaver generated by the mapping method of the embodiment is the interleaver used by terminal k; for uplink power domain NOMA, the fifth-level power reference generated by the mapping method of the embodiment is the power used by terminal k. For SCMA, RSMA, PDMA, MUSA, NCMA, NOCA systems, and a system taking the combination of multiple access signatures as multiple access signatures, o^th resource in the fourth-layer group, which is generated by the mapping method in the embodiment, is the resource used by terminal k.

Embodiment 7:

Foregoing six embodiments respectively discuss different cases, where reference signal and multiple access signature are in a one-to-one mapping, or in a one-to-multiple mapping. For any multiple access signature mode described in the third embodiment, and a hybrid multiple access system described in the first case of the fourth embodiment, this embodiment takes into account of a case, where capacity of a resource pool is less than number of available reference signals. At this time, even if two terminals use the same resource, as long as reference signals used by the two terminals are different, an eNB may still estimate a channel and further detect data of the two terminals. Besides, the objectives of differentiating terminals may still be achieved, by using a method of embedding a terminal ID into data. Thus, in the embodiment, a multiple-to-one mapping relationship between reference signal and multiple access signature is described.

Here, when a reference signal is determined with four parameters, that is, root sequence, cyclic shift, comb and OCC, the total number of users accessible on the same time-frequency resources in a system, that is, the total number of reference signals, is N=N_qN_αN_OCCN_comb. In addition, size of a resource pool (available codebook number) is K, K<N. In the embodiment, divide available resources of the resource pool into groups of three layers. The first-layer groups, the second-layer groups, the third-layer groups and position of resource in the third-layer groups are respectively represented by first, second, third, fourth parameters of a reference signal. Here, since number of resources is less than number of available reference signals, groups may be overlapped. That is, the same resource may belong to multiple groups, or there are the same resources in different groups, so as to complete multiple-to-one mapping from reference signal to resource.

Specifically, in the embodiment, the first, second, third, fourth parameters are respectively root sequence q, cyclic shift α, comb index n_comb and OCC index n_OCC. The mapping relationship in the embodiment may be described as follows: for root sequence q, cyclic shift α, comb index n_comb and OCC index n_OCC., corresponding index of multiple access signature (i.e., codebook) is:

It should be noted that, the mathematical expression of mapping rule here is only an example. Mapping is not limited to such mathematical expression. In practical applications, mapping may also be achieved with foregoing parameters, by using other modes. Based on such mapping rule, firstly obtain multiple access signatures with same number of reference signals, by way of replication. Specifically, multiple access signature k'=0,1,2,…,N-1 may be obtained, by copying multiple access signature k=0,1,2,…,K-1. k'=k+pK. P is a natural number. Subsequently, grouping rule of a resource pool is as follows. For multiple access signature k'=0,1,…,N-1, index of corresponding group on each layer is:

Thus, it can be seen that multiple access signature k corresponds to

different reference signals. In the example shown in Table 6, N_q=2, N_α=4, N_OCC=2, N_comb=2, and K=16, each resource corresponds to two different reference signals. When reference signals of two terminals have the same root sequence, the same cyclic shift, the same OCC, and different combs, the two terminals use the same multiple access signature.

It should be noted that, when size of a resource pool is equal to number of available reference signals, that is, K=N. Mapping rule of the embodiment becomes a one-to-one mapping, that is, as described in the fourth embodiment. In addition, when a reference signal is determined with two parameters (i.e., first and second parameters), or three parameters (i.e., first, second, third parameters), it is only necessary to divide the multiple access signatures into groups of one or two layers.

Embodiment 8:

In the seventh embodiment, take into account a mapping rule in a system taking a codebook as multiple access signatures, when the total number of multiple access signatures is less than number of terminals (that is, the total number of reference signals) accessed with the same time-frequency resources. This embodiment further discusses a case, where each terminal possesses multiple access flows, and the total number of multiple access signatures is less than the total number of data flows accessed with the same time-frequency resources. Specifically, K represents the total number of multiple access signatures. The number of terminals accessing the system is equal to the total number of reference signals N=N_qN_αN_OCCN_comb. N_s represents the maximum number of data flows transmittable by each terminal on the same time-frequency resources. The fourth embodiment has considered a case, where K=N×N_s. However, the fifth embodiment considers another case, where K<N and N_s=1. This embodiment considers still another case, where K<N×N_s and N_s>1.

In the embodiment, an apparatus in the present disclosure divides multiple access signatures of a resource pool into groups on four layers. The first-layer groups, the second-layer groups, the third-layer groups, the fourth-layer groups, and position of resource in the fourth-layer groups are respectively represented by the first, second, third, fourth parameters, and an index of a data flow. Here, since number of resources is less than number of available reference signals, groups may be overlapped. That is, the same resource may belong to multiple groups, or there are the same resources in different groups, so as to complete multiple-to-one mapping from reference signal to multiple access signature.

In the embodiment, the first, second, third, fourth parameters of a reference signal are respectively root sequence, cyclic shift, OCC and comb, the mapping relationship may be described as follows. For root sequence q, cyclic shift α, comb index n_comb, OCC index n_OCC, and index i_k of a data flow, an index of a corresponding multiple access signature is:

i_k=0,1,2,…,n_k-1, in which n_k≤N_s, represents number of flows transmitted by terminal k on the same time-frequency resources. It should be noted that, the mathematical expression of the mapping rule here is only an example. Mapping is not limited to such mathematical expression. In practical applications, mapping may also be achieved with foregoing parameters, by using other modes. Based on such mapping rule, the obtained grouping rule is as follows: firstly obtain multiple access signatures with the same number of reference signals, by way of replication. The multiple access signature k'=0,1,2,…,NN_s-1 is obtained by copying multiple access signature k=0,1,2,…,K-1. k'=k+pK, and p is a natural number. Subsequently, divide the copied resource pool into groups based on the following rules: for multiple access signature k'=0,1,…,NN_s-1, an index of a corresponding group on each layer is:

It should be noted that, as described in the sixth embodiment, when a reference signal is determined with two parameters (i.e., the first and second parameters), or three parameters (i.e., first, second, third parameters), it is only necessary to divide the multiple access signatures into groups on two or three layers.

Embodiment 9:

The foregoing eight embodiments have considered how to map to corresponding multiple access signatures in a grant-based system, by using a reference signal allocated by an eNB. In this embodiment, the embodiment discusses applications of a mapping solution of the present disclosure in a grant-free system are described. As shown in FIG.2, the embodiment describes a mapping from a preamble sequence to a reference signal. The mapping solution from a reference signal to a multiple access signature that is as described in the first to eight embodiments may be applied to this embodiment.

A device for the embodiment, divides preamble sequences into groups based on the following rule: M represents the total number of preamble sequences, the group of a preamble sequence m=0,1,…,M-1 is:

Thus, the apparatus determines root sequence index q (corresponds to the eighth parameter in the claims) of a reference signal with the index of the first-layer group, to which the selected preamble sequence belongs. Subsequently, determine cyclic shift α (corresponds to the seventh parameter in the claims) of the reference signal with the index of the second-layer group, to which the selected preamble sequence belongs. And then, the apparatus determines OCC index n_OCC (corresponds to the sixth parameter in the claims) of the reference signal with the index of the third-layer group, to which the selected preamble sequence belongs. Finally, the apparatus determines comb index n_comb (corresponds to the fifth parameter in the claims) of the reference signal, by using position of the selected preamble sequence in the third-layer group. The embodiment describes a case, where it is necessary to determine four parameters (e.g. root-sequence, cyclic shift, comb, and OCC) of a reference signal. In some embodiments, determination sequences of the four parameters may be exchanged. In addition, the mapping rule in the embodiment is also applicable to a case, where it is necessary to determine three and two parameters of a reference signal. At this time, it is necessary to divide preamble sequences into groups on two layers or on one layer. For a case, where it is necessary to determine one parameter of a reference signal, the one parameter of the reference signal may be computed directly by using the sequence number of the preamble sequence. The three parameters, two parameters and one parameter of the designed reference signal may be any combination of root sequence, cyclic shift, OCC and comb.

It should be noted that, when total number M of preamble sequences is less than, and/or, equal to total number N=N_qN_αN_OCCN_comb of available reference signals, that is, M≤N, such mapping rule enables any preamble sequence to map to the unique reference signal. When the total number M of the preamble sequences is greater than the total number of available reference signals, that is, M>N, such mapping rule enables multiple preamble sequences to map to one reference signal. Specifically, for a preamble sequence with number m'+p·N, m'≤N-1,

natural number, m'+pN≤M-1, all the preamble sequences with number m'+p·N are mapped to a reference signal corresponding to preamble sequence m'. For example, when N_q=2, N_α=4, N_OCC=2, N_comb=2, and M=64, preamble sequences with numbers 0 and 32 are mapped to the same reference signal, that is, q=0, α=0, n_OCC=0, n_comb=0.

Corresponding to the foregoing method, the present disclosure also provides an device apparatus (or device) for mapping between a reference signal and a multiple access signature. As shown in FIG.7, the apparatus includes a reference signal determining module, a mapping module, and a transmitting module.

The reference signal determining module is configured to determine a reference signal used by uplink data transmission.

The mapping module is configured to determine a multiple access signature, based on a mapping relationship between reference signals and multiple access signatures.

The transmitting module is configured to communicate, by using the multiple access signatures.

Preferable, the reference signal determining module is further configured to determine the reference signal used by uplink data transmission, based on a selected preamble sequence and a pre-set rule.

The foregoing mapping method in the present disclosure is applied to a grant-free system, it is necessary to map to root sequence index, cyclic shift, orthogonal cover code (OCC) index and comb index of a reference signal used by uplink data transmission, based on a selected preamble sequence and a pre-set rule. And then, map to the multiple access signature with foregoing mapping method. The application also provides a device for mapping between a reference signal and a multiple access signature. By adopting the solution of the application, signaling overheads may be reduced.

In a new multiple access technology, an eNB needs additional signaling overheads to inform a terminal to communicate with which resource. The present disclosure provides a method for determining a mapping relationship between a reference signal and a resource pool, such that the eNB and terminal may obtain corresponding multiple access signature information, by using allocated reference signals, thereby avoiding additional signaling overheads and transmission delay. By adopting the mapping method in the present disclosure, corresponding multiple access signatures may be dynamically obtained, based on generation method of a reference signal and an application scene (may be in a one-to-one mapping, one-to-multiple mapping, or multiple-to-one mapping). The solution in the present disclosure may be simultaneously applied in a grant-free system, so as to simplify process and reduce complexity.

The foregoing is only preferred embodiments of the present disclosure, which is not for use in limiting the present disclosure. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present disclosure should be covered by the protection scope of the present disclosure.

Claims

A method for mapping between a reference signal and a multiple access signature in a wireless communication, comprising:

determining a multiple access signature corresponding to a reference signal for using an uplink data transmission, based on a mapping relationship between reference signals and multiple access signatures; and,

communicating by using the multiple access signature.
The method according to claim 1, wherein determining the multiple access signature based on the mapping relationship between reference signals and multiple access signatures comprises:

taking a parameter for generating the reference signal as an index; and

determining the multiple access signature corresponding to the parameter based on a pre-set mapping rule.
The method according to claim 2, wherein when the multiple access signatures are an interleaver, and taking T1 parameters as the index, 1≤T1≤4, determining the corresponding multiple access signature based on the pre-set mapping rule comprises:

taking a pre-stored mother interleaver as a first-level mother interleaver; and

generating a next level mother interleaver by taking any unused parameter of the T1 parameters as the index, based on the pre-set mapping rule, until taking the last unused parameter of the T1 parameters as the index to generate an interleaver for multiple access.
The method according to claim 2, wherein when the multiple access signature is power, and taking T2 parameters as the index, 1≤T2≤4, determining the corresponding multiple access signature based on the pre-set mapping rule comprises:

taking a predetermined power reference as a first-level power reference; and

generating a next level power reference by taking any unused parameter of the T2 parameters as the index, based on the pre-set mapping rule, until generating the power for multiple access by taking the last unused parameter of the T2 parameters as the index.
The method according to claim 2, wherein when the multiple access signatures are a combination of at least one or two of:

space resource, bit-level interleaver, symbol-level interleaver, power, non-orthogonal codebook, orthogonal codebook, scramble sequence, or grid-mapping pattern;

wherein when taking one parameter of the reference signal as the index, determining the corresponding multiple access signature by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule comprises selecting the corresponding multiple access signatures based on the parameter,

wherein when taking two parameters of the reference signal as the index, the method further comprises dividing the multiple access signatures into N₁ groups, wherein each group comprises N₂ resources, N₁ and N₂ are respectively numbers of a first parameter and a second parameter of the two parameters,

wherein determining the corresponding multiple access signature by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, comprises:

selecting a group of the multiple access signatures based on the first parameter; and

selecting the used multiple access signatures within the group based on the second parameter,

wherein when taking three parameters of the reference signal as the index, the method further comprises: dividing the multiple access signatures into N₁first-layer groups, wherein each first-layer group possesses N₂*N₃ resources; dividing N₂*N₃ resources of each first-layer group into N₂second-layer groups, wherein each second-layer group comprises N₃ resources; N₁,N₂andN₃ are respectively numbers of a first parameter, a second parameter, a third parameter of the three parameters; wherein mapping to the corresponding multiple access signatures by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, comprises:

selecting a first-layer group of the multiple access signatures based on the first parameter;

selecting a second-layer group of the multiple access signatures based on the second parameter; and

selecting the used multiple access signatures within the selected second-layer group, based on the third parameter,

wherein when taking four parameters of the reference signal as the index, the method further comprises:

dividing the multiple access signatures into N₁ first-layer groups, wherein each first-layer group comprises N₂*N₃* N₄ resources;

dividing N₂*N₃*N₄ resources of each first-layer group into N₂ second-layer groups, wherein each second-layer group comprises N₃*N₄ resources;

dividing N₃*N₄ resources of each second-layer group into N₃ third-layer groups, wherein each third-layer group comprises N₄ resources, wherein N₁, N₂, N₃and N₄ are respectively numbers of a first parameter, a second parameter, a third parameter and a fourth parameter of the four parameters, and

wherein determining the corresponding multiple access signature by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, comprises:

selecting a first-layer group of the multiple access signatures based on the first parameter;

selecting a second-layer group of the multiple access signatures based on the second parameter;

selecting a third-layer group of the multiple access signatures based on the third parameter; and

selecting the used multiple access signatures within the selected third-layer group based on the fourth parameter.
The method according to claim 3, wherein when one terminal transmits at least two data flows with the same time-frequency resource, determining the corresponding multiple access signature by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, comprises:

taking the interleaver for multiple access as the last level mother interleaver; and,

generating an interleaver used by each data flow by using the index of the data flow, based on the last level mother interleaver and the pre-set mapping rule.
The method according to claim 4, wherein when one terminal transmits at least two data flows with the same time-frequency resource, determining the corresponding multiple access signature by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, comprises:

taking the power for multiple access as the last level power reference;

generating the power used by each data flow based on the index of the data flow, by using the last level power reference and the pre-set mapping rule.
The method according to claim 5, wherein in a case where take one parameter of the reference signal as the index, when one terminal transmits at least two data flows with the same time-frequency resource, the method further comprises dividing the multiple access signatures into N₁ groups, wherein each group comprises N_s resources, N₁ is number of the one parameter, N_s is the maximum number of data flows transmittable by each terminal with the same time-frequency resources,

wherein determining the corresponding multiple access signature, by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, comprises:

selecting a first-layer group of the multiple access signatures based on the first parameter; and

selecting the multiple access signatures used by each data flow within the selected first-layer group, based on the index of the data flow,

wherein in a case where take two parameters of the reference signal as the index, when one terminal transmits at least two data flows with the same time-frequency resource, the method further comprises:

dividing the multiple access signatures into N₁first-layer groups, wherein each first-layer group comprises N₂* N_sresources; and

dividing N₂* N_s resources of each first-layer group into N₂ second-layer groups, wherein each second-layer group comprises N_s resources, wherein N_s is the maximum number of data flows transmittable by each terminal with the same time-frequency resources,

wherein determining the corresponding multiple access signature, by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, comprises:

selecting a first-layer group of the multiple access signatures based on the first parameter;

selecting a second-layer group of the multiple access signatures based on the second parameter; and

selecting the multiple access signatures used by each data flow within the selected second-layer group, based on the index of the data flow,

wherein in a case where take three parameters of the reference signal as the index, when one terminal transmits at least two data flows with the same time-frequency resource, the method further comprises:

dividing the multiple access signatures into N₁ first-layer groups, wherein each first-layer group comprises N₂* N₃ * N_s resources;

dividing the N₂* N₃ * N_s resources of each first-layer group into N₂ second-layer groups, wherein each second-layer group comprises N₃ * N_s resources; and

dividing the N₃ * N_s resources of each second-layer group into N₃ third-layer groups, wherein each third-layer group comprises N_s resources; N_s is the maximum number of data flows transmittable by each terminal with the same time-frequency resources,

wherein determining the corresponding multiple access signature by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, comprises:

selecting a first-layer group of the multiple access signatures based on the first parameter;

selecting a second-layer group of the multiple access signatures based on the second parameter;

selecting a third-layer group of the multiple access signatures based on the third parameter; and

selecting the multiple access signatures used by each data flow within the selected third-layer group, based on the index of the data flow,

wherein in a case where take four parameters of the reference signal as the index, when one terminal transmits at least two data flows with the same time-frequency resource, the method further comprises:

dividing the multiple access signatures into N₁ first-layer groups, wherein each first-layer group comprises N₂* N₃ * N₄ * N_s resources;

dividing the N₂* N₃ * N₄ * N_s resources of each first-layer group into N₂ second-layer groups, wherein each second-layer group comprises N₃ * N₄ * N_s resources;

dividing the N₃ * N₄ * N_s resources of each second-layer group into N₃ third-layer groups, wherein each third-layer group comprises N₄ * N_s resources; and

dividing the N₄ * N_s resources of each third-layer group into N₄ fourth-layer groups, wherein each fourth-layer group comprises N_s resources, N_s is the maximum number of data flows transmittable by each terminal with the same time-frequency resources, and

wherein determining the corresponding multiple access signature by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, comprises:

selecting a first-layer group of the multiple access signatures based on the first parameter;

selecting a second-layer group of the multiple access signatures based on the second parameter;

selecting a third-layer group of the multiple access signatures based on the third parameter;

selecting a fourth-level group of the multiple access signatures based on the fourth parameter; and

selecting the multiple access signatures used by each data flow within the selected fourth-level group, based on the index of the data flow.
The method according to any of claims 3 to 8, wherein when the multiple access signatures are a combination of a bit-level interleaver and at least one of: a space resource, power, a symbol-level interleaver, a non-orthogonal codebook, an orthogonal codebook, a scramble sequence, or a grid-mapping pattern, determining the corresponding multiple access signature by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, comprises:

taking some parameters or all the parameters for generating the reference signal as the index, respectively determining an interleaver corresponding to multiple access and other multiple access signatures, based on the pre-set mapping rule.
The method according to any of claims 3 to 8, wherein when the multiple access signatures are a combination of power and at least one of: a space resource, a bit-level interleaver, a symbol-level interleaver, a non-orthogonal codebook, an orthogonal codebook, a scramble sequence, or a grid-mapping pattern, determining the corresponding multiple access signature by taking the parameter for generating the reference signal as the index, based on the pre-set mapping rule, comprises:

taking all the parameters or some parameters for generating the reference signal as the index, respectively determining the power corresponding to multiple access and other multiple access signatures, based on the pre-set mapping rule.
The method according to claim 5, wherein when a total number of multiple access signatures is less than a total number of reference signals, the method further comprises:

enabling the total number of multiple access signatures to be the same as the total number of reference signals, by way of replication, and dividing the copied multiple access signatures into groups.
The method according to claim 8, wherein when a total number of multiple access signatures is less than a production of a total number of reference signals and a maximum number of transmission flows of a terminal, the method further comprises:

enabling the total number of multiple access signatures to be the same as the product, which is obtained after multiplying the total number of reference signals by the maximum number of transmission flows of the terminal, by way of replication, and dividing the copied multiple access signatures into groups.
The method according to claim 1, further comprising:

determining the at least one parameter for generating the reference signal based on a pre-set rule, by using a selected preamble sequence and a mapping relationship between preamble sequence and parameters for generating the reference signal,

wherein the wireless communication is in a grant-free system,

wherein the reference signal is used by the uplink data transmission, and

wherein a number of the determined at least one parameter is one of 1 to 4.
The method according to claim 13, determining the parameter based on the pre-set rule, by using the selected preamble sequence and the mapping relationship between preamble sequence and parameter for generating the reference signal comprises:

when the number is one, determining the parameter based on the preamble sequence;

when the number is two, dividing the preamble sequence into N₁₁ first-layer groups; determining the sixth parameter in the two parameters, by using position of the selected preamble sequence in the first-layer groups; determining the fifth parameter in the two parameters, by using the first-layer group of the selected preamble sequence; wherein N₁₁ is number of the fifth parameter;

when the number is three, dividing the preamble sequence into N₁₁ first-layer groups, dividing the preamble sequence of each first-layer group into N₂₁ second-layer groups; determining the seventh parameter of the three parameters, by using position of the selected preamble sequence in the second-layer groups; determining the sixth parameter of the three parameters, by using the second-layer group of the selected preamble sequence; determining the fifth parameter of the three parameters, by using the first-layer group of the selected preamble sequence; wherein N₁₁ is number of the fifth parameter, N₂₁ is number of the sixth parameter; and

when the number is four, dividing the preamble sequence into N₁₁ first-layer groups; dividing the preamble sequence of each first-layer group into N₂₁ second-layer groups; dividing the preamble sequence of each second-layer group into N₃₁ third-layer groups; determining the eighth parameter of the four parameters, by using position of the selected preamble sequence in the third-layer groups; determining the seventh parameter of the four parameters, by using the third-layer group of the selected preamble sequence; determining the sixth parameter of the four parameters, by using the second-layer group of the selected preamble sequence; determining the fifth parameter of the four parameters, by using the first-layer group of the selected preamble sequence; wherein N₁₁, N₂₁, N₃₁ are respectively numbers of the fifth parameter, the sixth parameter, and the seventh parameter.
An apparatus for mapping between a reference signal and a multiple access signature, comprising a reference signal determining module, a mapping module and a transmitting module, wherein the apparatus configured to implement one of claims 1 to 14.