CN107733599B

CN107733599B - Method and apparatus for demodulation reference signal enhancement

Info

Publication number: CN107733599B
Application number: CN201610659417.8A
Authority: CN
Inventors: 苏苓; 张闽; 王笑一; 弗兰克·谢
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Oyj
Priority date: 2016-08-12
Filing date: 2016-08-12
Publication date: 2020-09-11
Anticipated expiration: 2036-08-12
Also published as: CN107733599A; WO2018029527A1

Abstract

Embodiments of the present disclosure relate to methods and apparatus for demodulation reference signal enhancement. For example, embodiments of the present disclosure provide a method of communication. The method comprises the following steps: determining, at a network device, whether Interleaved Frequency Division Multiple Access (IFDMA) is enabled for transmission of an uplink demodulation reference signal (DMRS); generating an indication of whether IFDMA is enabled; and sending an indication to the terminal device. A corresponding method implemented at the terminal device is also disclosed, as well as a network device and a terminal device capable of implementing the above method.

Description

Method and apparatus for demodulation reference signal enhancement

Technical Field

Embodiments of the present disclosure relate generally to communication technology and, more particularly, to methods and apparatus for demodulation reference signal enhancement.

Background

Currently, for Long Term Evolution (LTE) systems, enhanced uplink DMRS (demodulation reference signal) transmission has been agreed in current 3GPP standardization work to support more than two orthogonal DMRSs for MU-MIMO (multi-user multiple input multiple output) transmission with partially overlapping bandwidth allocation.

In the LET specification, a network device (e.g., eNB) transmits DMRS configuration information to a UE by using DCI (downlink control information). Existing

DCI formats

0 and 4 are used to schedule a Physical Uplink Shared Channel (PUSCH). However, the DCI messages in

DCIformat

0 and 4 cannot support more than two orthogonal DMRSs for MU-MIMO transmission with partial overlap bandwidth allocation. The reason is that existing

DCI formats

0 and 4 have a CS (cyclic shift)/OCC (orthogonal cover code) configuration of 3 bits for DMRSs, which can support only a maximum of two orthogonal DMRSs. Therefore, a network device and a terminal device for DMRS enhancement are needed.

IFDMA (interleaved frequency division multiple access) technology has good prospects in multiplexing more than two terminal equipments (UEs) for uplink MU-MIMO transmission. IFDMA was originally proposed by Uli sor et al in 1998 to achieve multiple access in IFDMA systems by allocating different sub-carriers (e.g., odd, even sub-carriers) to each user. Due to the complete orthogonality among the subcarriers of different users, multi-user interference (MUI) can be completely avoided under certain conditions. However, there is currently no mechanism to use IFDMA techniques for uplink DMRS.

Disclosure of Invention

In general, embodiments of the present disclosure propose communication methods for demodulation reference signal enhancement and corresponding methods and devices.

In a first aspect, embodiments of the present disclosure provide a communication method. The method comprises the following steps: determining, at a network device, whether Interleaved Frequency Division Multiple Access (IFDMA) is enabled for transmission of an uplink demodulation reference signal (DMRS); generating an indication of whether IFDMA is enabled; and sending an indication to the terminal device.

In a second aspect, embodiments of the present disclosure provide a method of communication. The method comprises the following steps: receiving, at a terminal device, an indication from a network device whether Interleaved Frequency Division Multiple Access (IFDMA) is enabled; and parsing the indication to determine a transmission mode of an uplink demodulation reference signal (DMRS).

In a third aspect, embodiments of the present disclosure provide a network device. The network device includes: a controller configured to determine whether Interleaved Frequency Division Multiple Access (IFDMA) is enabled for transmission of an uplink demodulation reference signal (DMRS), and to generate an indication of whether IFDMA is enabled; and a transceiver configured to transmit an indication to the terminal device.

In a fourth aspect, embodiments of the present disclosure provide a terminal device. The terminal device includes: a transceiver configured to receive an indication of whether Interleaved Frequency Division Multiple Access (IFDMA) is enabled from a network device; and a controller configured to parse the indication to determine a transmission mode of an uplink demodulation reference signal (DMRS).

As will be understood from the following description, according to the embodiments of the present disclosure, by using IFDMA technology for uplink DMRS, a network device may send an indication of whether IFDMA is enabled to terminal devices, cause each terminal device receiving the indication to adopt a corresponding strategy (e.g., with or without IFDMA) to transmit uplink DMRS on an allocated carrier, and then implement multiplexing of more terminal devices for uplink MU-MIMO transmission, thereby improving system performance.

It should be understood that the statements herein reciting aspects are not intended to limit the critical or essential features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become apparent from the following description.

Drawings

The above and other features, advantages and aspects of various embodiments of the present disclosure will become more apparent by referring to the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, like or similar reference characters designate like or similar elements, and wherein:

FIG. 1 illustrates an example communication network in which embodiments of the present disclosure may be implemented;

fig. 2 illustrates a high-level piping diagram of a network device signaling interactions with one terminal device for DMRS transmission, in accordance with certain embodiments of the present disclosure;

FIG. 3 illustrates a flow chart of an example communication method in accordance with certain embodiments of the present disclosure;

fig. 4A and 4B show schematic diagrams of allocating subcarriers without using extension bits in a cyclic shift domain according to some embodiments of the present disclosure, and fig. 4C and 4D show schematic diagrams of allocating subcarriers without using extension bits in a cyclic shift domain according to improved embodiments of the present disclosure;

fig. 5A and 5B illustrate schematic diagrams of allocating subcarriers using extended bits in the cyclic shift domain according to certain embodiments of the present disclosure;

fig. 6 illustrates a flow chart of an example communication method in accordance with certain other embodiments of the present disclosure;

FIG. 7 illustrates a block diagram of an apparatus according to certain embodiments of the present disclosure;

FIG. 8 illustrates a block diagram of an apparatus according to certain embodiments of the present disclosure; and

fig. 9 illustrates a block diagram of an apparatus in accordance with certain embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numbers refer to the same or similar elements.

Detailed Description

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain embodiments of the present disclosure are shown in the drawings, it is to be understood that the present disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but rather are provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the disclosure are for illustration purposes only and are not intended to limit the scope of the disclosure.

The term "network device" as used herein refers to a base station or other entity or node having a particular function in a communication network. A "base station" (BS) may represent a node B (NodeB or NB), an evolved node B (eNodeB or eNB), a Remote Radio Unit (RRU), a Radio Head (RH), a Remote Radio Head (RRH), a relay, or a low power node such as a pico base station, a femto base station, or the like. In the context of the present disclosure, the terms "network device" and "base station" may be used interchangeably for purposes of discussion convenience, and may primarily be referred to as an eNB as an example of a network device.

The term "terminal equipment" or "user equipment" (UE) as used herein refers to any terminal equipment capable of wireless communication with a base station or with each other. As an example, the terminal device may include a Mobile Terminal (MT), a Subscriber Station (SS), a Portable Subscriber Station (PSS), a Mobile Station (MS), or an Access Terminal (AT), and the above-described devices in a vehicle. In the context of the present disclosure, the terms "terminal device" and "user equipment" may be used interchangeably for purposes of discussion convenience.

The terms "include" and variations thereof as used herein are inclusive and open-ended, i.e., "including but not limited to. The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". Relevant definitions for other terms will be given in the following description.

Although orthogonal DMRSs supporting two UEs paired for MU-MIMO have been proposed in the 3GPP standard, the number of UEs is likely to be expanded according to the demand. Existing

DCI formats

0 and 4 support orthogonal DMRSs for two UEs, i.e., two UEs are allocated different OCCs. As a potential alternative, if IFDMA techniques are incorporated, the number of supported UEs can be at least doubled. For example, when three UEs are paired together for uplink MU-MIMO, where two UEs are assigned the same OCC code and the other UE is assigned another different OCC code. IFDMA may be used to maintain orthogonal DMRSs for two UEs that are allocated the same OCC code, e.g., the two UEs may transmit DMRSs uplink on odd and even subcarriers, respectively. However, the existing

DCI formats

0 and 4 cannot provide necessary information for allocating subcarriers to the UE.

Therefore, an efficient way is needed to enable the UE to know whether IFDMA is enabled in time. Further, with IFDMA enabled, the UE needs to know the subcarriers used for uplink DMRS transmission, e.g., whether odd or even subcarriers when the repetition factor (RPF) is 2.

To address these and other potential problems, at least in part, embodiments of the present disclosure provide entirely new communication methods and corresponding devices. According to embodiments of the present disclosure, a network device may determine whether IFDMA is enabled for transmission of an uplink DMRS. The network device may then generate an indication of whether IFDMA is enabled and transmit the indication to the end device. It should be noted that the indication of whether IFDMA is enabled sent to each terminal device may be different, that is, an indication that IFDMA is enabled may be sent to one or more terminal devices, and an indication that IFDMA is not enabled may be sent to other terminal devices.

In this way, the network device may send an indication of whether IFDMA is enabled to the terminal device, so that each terminal device receiving the indication adopts a corresponding policy to transmit the uplink DMRS on the allocated carrier, thereby implementing multiplexing of more terminal devices for uplink MU-MIMO transmission, thereby improving system performance.

Fig. 1 illustrates an example communication network 100 in which embodiments of the present disclosure may be implemented. The communication network 100 comprises a network device 150 and a plurality of terminal devices, namely a first terminal device 110, a second terminal device 120, a third terminal device 130 and a fourth terminal device 140. These end devices 110 to 140 may communicate with the network device 150 and attempt to utilize the same resources quickly.

It should be understood that the number of network devices and terminal devices shown in fig. 1 is for illustration purposes only and is not intended to be limiting. Network 100 may include any suitable number of network devices and terminal devices. In particular, embodiments of the present disclosure, which will be described below, may be fully applicable to a single user equipment.

According to an embodiment of the present disclosure, the network device 150 may pair together the first terminal device 110, the second terminal device 120, the third terminal device 130 and the fourth terminal device 140 for uplink MU-MIMO. It should be understood that in addition to pairing the first terminal device 110, the second terminal device 120, the third terminal device 130 and the fourth terminal device 140, the network device 150 may also be paired in other ways. As an example, three UEs may be paired together, i.e. the first terminal device 110, the second terminal device 120 and the third terminal device 130, for uplink MU-MIMO, as described above.

Communications in network 100 may be implemented in accordance with any suitable communication protocol, including, but not limited to, first-generation (1G), second-generation (2G), third-generation (3G), fourth-generation (4G), and fifth-generation (5G) cellular communication protocols, wireless local area network communication protocols such as Institute of Electrical and Electronics Engineers (IEEE)802.11, and/or any other protocol now known or later developed. Moreover, the communication may utilize any suitable wireless communication technique including, but not limited to, Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple Input Multiple Output (MIMO), orthogonal frequency division multiple access (OFDM), and/or any other technique now known or later developed.

According to embodiments of the present disclosure, network device 150 may determine whether IFDMA is enabled for transmission of the uplink DMRS. Network device 150 may then generate an indication of whether IFDMA is enabled and transmit the indication to first end device 110, second end device 120, third end device 130, and fourth end device 140. As described above, the indication of whether IFDMA is enabled or not transmitted to the first terminal device 110, the second terminal device 120, the third terminal device 130, and the fourth terminal device 140 may be different. That is, an indication that IFDMA is enabled may be transmitted to the first terminal device 110 and the second terminal device 120, and an indication that IFDMA is enabled may be transmitted to the third terminal device 130 and the fourth terminal device 140. The first terminal device 110 and the second terminal device 120 are assigned the same OCC code, while the third terminal device 130 and the fourth terminal device 140 are assigned another OCC code.

IFDMA may be used to maintain orthogonal DMRSs for two UEs that are allocated the same OCC code, e.g., the two UEs may transmit DMRSs uplink on odd and even subcarriers, respectively. Since the network device 150 sends the indication of whether IFDMA is enabled to the first terminal device 110, the second terminal device 120, the third terminal device 130, and the fourth terminal device 140, each terminal device that receives the indication adopts a corresponding policy to transmit the uplink DMRS on the allocated carrier, thereby implementing multiplexing of the first terminal device 110, the second terminal device 120, the third terminal device 130, and the fourth terminal device 140 for uplink MU-MIMO transmission, thereby improving system performance.

Fig. 2 illustrates a high-level piping diagram in which a network device 150 signals interaction with one of terminal devices 110 for DMRS transmission, in accordance with certain embodiments of the present disclosure. As shown in fig. 2, before performing the uplink DMRS, the network device 150 may send an indication to the paired terminal devices whether IFDMA is enabled. Fig. 2 only schematically shows one of the terminal devices, that is, the first terminal device 110 parses the indication and transmits the uplink DMRS according to the sub-carriers allocated by the indication. The indication of whether IFDMA is enabled sent to each end device may be different.

The principles and specific embodiments of the present disclosure will be described in detail below with reference to fig. 3-6 from the perspective of the network device 150 and the first terminal device 110, respectively. Referring first to fig. 3, a flow diagram of an example communication method 300 is shown, in accordance with certain embodiments of the present disclosure. It is to be appreciated that the method 300 may be implemented, for example, at the network device 150 as shown in fig. 1 and 2. For ease of description, the method 300 is described below in conjunction with fig. 1 and 2.

As shown, at 305, the network device 150 determines whether IFDMA is enabled for transmission of the uplink DMRS. At 310, network device 150 generates an indication of whether IFDMA is enabled. At 315, the network device 150 sends the indication to the first terminal device 110.

In this way, the network device 150 may send an indication of whether IFDMA is enabled to the first terminal device 110, and cause the first terminal device 110 receiving the indication to adopt a corresponding strategy to transmit the uplink DMRS on the allocated carrier, so that the IFDMA technique is combined with the uplink DMRS transmission to enhance the uplink DMRS. The processing at the terminal side will be described in detail later in conjunction with fig. 6.

In some embodiments, 310 may include network device 150 creating a higher layer parameter to indicate whether IFDMA is enabled, e.g., creating one or more parameters at a Radio Resource Control (RRC) layer to indicate whether IFDMA is enabled. When the higher layer parameters indicate that IFDMA is enabled, the terminal device may be allocated subcarriers for transmitting the uplink DMRS using the following table 1.

TABLE 1

An existing table (e.g., Release 10) may be used when a higher layer parameter indicates that IFDMA is not enabled. In table 1, comb1 and comb2 of the IFDMA comb (comb) may be used to represent odd and even subcarriers, and vice versa. As an example, comb1 denotes odd subcarriers, comb2 denotes even subcarriers. An exemplary allocation method will be described in detail below in conjunction with table 2 and fig. 4A and 4B. It should be understood that there are many ways to allocate IFDMA sub-carriers and therefore other variations and modifications will occur to those skilled in the art in light of the allocation described in this disclosure.

In this way, while the enhanced uplink DMRS is implemented, it is convenient to change the existing system, especially not change the conventional DCI configuration.

In some embodiments, 310 may further include the network device 150 generating DCI indicating whether IFDMA is enabled. In this way, although the DCI needs to be changed, since the lower layer is adjusted, the enhanced uplink DMRS is implemented, and at the same time, the configuration can be more flexibly performed in response to the change of the system, so that the allocation of subcarriers is more optimized.

In some embodiments, in response to IFDMA being enabled, network device 150 may generate DCI to indicate the subcarriers for first terminal device 110 to perform the uplink DMRS transmission. Specifically, schemes for indicating allocated subcarriers may be classified into two categories: in the first category, no DCI bit is added, that is, extension bits in the cyclic shift domain are not used, but subcarriers need to be reallocated by using the current cyclic shift domain; second, bits of the DCI are added, i.e., an extension bit in the cyclic shift domain is used, and other bits in the DCI may be utilized, which are used to indicate whether IFDMA is enabled or not to allocate subcarriers.

The first type of subcarrier allocation scheme is discussed first, that is, DCI bits are not increased, CS/OCC configuration is not changed, and only an implicit IFDMA comb (comb) indication is added under the CS domain. Table 2 below shows a specific allocation of subcarriers.

TABLE 2

In the context of table 2, the following,

a specific value of Cyclic Shift (CS) is shown, four column values respectively representing four layers, and four columns in the OCC column also represent the four layers. It should be understood that the number of layers described herein is variable and scalable. Generating DCI to allocate IFDMA subcarriers specifically includes: a CS domain is created in the DCI, and information in the CS domain is used to specify that first terminal device 110 is assigned odd numbered subcarriers and second terminal device 120 is assigned even numbered subcarriers, or that first terminal device 110 is assigned even numbered subcarriers and second terminal device 120 is assigned odd numbered subcarriers, and that first terminal device 110 and second terminal device 120 are assigned the same OCC (see table 2 that each pair of odd and even subcarriers has the same OCC of layer 1 and layer 2). As described above, the CS/OCC configuration does not change. While the last column of the table shows an indication of the IFDMA comb, i.e. an indication of odd or even subcarriers at a repetition factor of 2. A method of allocating IFDMA subcarriers will be described below with reference to fig. 4A and 4B.

Fig. 4A and 4B illustrate diagrams of subcarrier allocation without using extension bits in the cyclic shift domain according to certain embodiments of the present disclosure. As an example, first, the row with OCC first, second level [ 11 ] is selected in table 2, so that the corresponding values of the first column in CS specific values, i.e., 0, 4, 2, 9, are found in these four rows. Thereafter, as shown in fig. 4A, 9 has the largest separation distance (separation) with respect to 0, 4, and 2, and therefore, 9 can be selected as an odd subcarrier. And since the spacing distances of 2 and 4 to 9 are the same and greater than the spacing distance of 0 to 9, one of them is optionally an even subcarrier, and 2 is selected as the even subcarrier here. The remaining 0 s and 4 s are selected as no IFDMA. Next, select the row with OCC first and second levels 1-1 in table 2, and find the corresponding values in the first column, i.e., 6, 3, 8, 10, in the CS specific values. Thereafter, as shown in fig. 4B, 3 has the largest separation distance with respect to 6, 8, and 10, and thus 3 may be selected as the odd subcarrier. And since the spacing distances of 8 and 10 to 3 are the same and greater than the spacing distance of 6 to 3, one of them is optionally an even subcarrier, where 8 is selected as the even subcarrier. The remaining 6 and 10 are selected as no IFDMA. The allocation of IFDMA subcarriers is thus completed. It should be understood that there are many ways to allocate IFDMA sub-carriers and therefore other variations and modifications will occur to those skilled in the art in light of the allocation described in this disclosure.

As another example, fig. 4C and 4D illustrate diagrams for allocating subcarriers without using extension bits in a cyclic shift domain according to an improved embodiment of the present disclosure. As shown in fig. 4C and 4D, by reversing the positions of fig. 2 and 3, 9 and 3 have the largest distance apart as shown in fig. 4C, and 8 and 2 have the largest distance apart as shown in fig. 4D. Therefore, the subcarriers allocated to the paired terminal devices by this embodiment have better correlation. Table 3 below shows the specific allocation of improved sub-carriers, and it can be seen that the CS values in rows 3 and 5 of table 3 are exchanged.

TABLE 3

As another example, a CS value may also be selected

Four rows of 0, 6, 3, 9 in the first layer are used for IFDMA subcarrier allocation as shown in table 4 below. It can be seen that table 4 differs from table 2 in that four CS domains are selected for IFDMA configuration.

TABLE 4

In addition, the DMRS with the length of 6 in the narrowband internet of things (NB-loT) in R13(Release 13) may also be allocated with subcarriers. Since there are 12 different values for the cyclic shift as shown in tables 1-4, while the DMRS of length 6 in NB-loT has only 4 different

cyclic shift values

0, 1, 2, 4, these 4 values can be mapped to 0, 2, 4, 8. The specific allocation manner can be described with reference to fig. 4A and 4B. The specific IFDMA subcarrier allocation results are shown in table 5. In addition, the skilled person can also make changes to this table, for example, table 5 is modified with reference to the modification of table 3. In addition, table 5 may be merged with table 1, table 2, table 3, or table 4, respectively, and details are not repeated.

TABLE 5

The second type of subcarrier allocation scheme, i.e., increasing the bits of the DCI, will be discussed below. For example, an extension bit in the cyclic shift domain may be used, or other bits in the DCI may be utilized, which are used to indicate whether IFDMA is enabled for allocating subcarriers. Fig. 5A and 5B illustrate diagrams of subcarrier allocation using extension bits in a cyclic shift domain according to some embodiments of the present disclosure, and specific allocation may refer to the description with respect to fig. 4A and 4B. Table 6 below illustrates the specific allocation of subcarriers by adding an extension bit before the original three bits in the CS domain. The extension bit of 0 may indicate that there is no IFDMA for the DMRS, and the extension bit of 1 may indicate that there is IFDMA for the DMRS. In addition, table 6 can be combined with table 5, and details are not repeated.

TABLE 6

Since there are 8 new entries for IFDMA, the IFDMA is allowed to have a repetition factor of 4 and two OCC codes. The 12 sub-carriers in one resource block can be divided into 4 comb (comb) groups. If the repetition factor used is only 2, comb1 and comb 3 fall back to odd subcarriers and comb2 and comb 4 fall back to even subcarriers. Further, the table may be modified by those skilled in the art, for example, table 6 is modified in a manner of referring to table 3.

Those skilled in the art will note that the physical hybrid automatic repeat indicator channel (PHICH) is paired by an index

Is shown in which

Is the number of PHICH groups, and

is the orthogonal sequence index in the set, defined by the formula:

wherein n is_DMRSThe cyclic shift of the DMRS field with uplink DCI format 4 in the latest Physical Downlink Control Channel (PDCCH) (see table 7, i.e. table 9.1.2-2 in the standard) is mapped.

TABLE 7

Since the cyclic shift of the DMRS field is changed to 4 bits in table 7 above, only the last three bits of the cyclic shift field are used to obtain n in order to continue using the existing table 7_DMRSThe extension bit is ignored, thereby avoiding PHICH index collision.

Fig. 6 illustrates a flow diagram of an example communication method 600 in accordance with certain embodiments of the present disclosure. It is to be appreciated that method 600 may be implemented, for example, at first terminal device 110 as shown in fig. 1 and 2. For ease of description, the method 600 is described below in conjunction with fig. 1 and 2.

As shown, at 605, the first end device 110 receives an indication of whether IFDMA is enabled from the network device 140. At 610, the first terminal device 110 parses the indication to determine the transmission mode of the uplink DMRS.

As described above, in some embodiments, in 610 may be included the first terminal device 110 parsing parameters created by higher layers to indicate whether IFDMA is enabled, e.g., parsing parameters created by a Radio Resource Control (RRC) layer to indicate whether IFDMA is enabled. In this way, while the enhanced uplink DMRS is implemented, it is convenient to change the existing system, especially not to change the conventional downlink DCI configuration.

In some embodiments, 610 may also include the first terminal device 110 parsing downlink DCI indicating whether IFDMA is enabled. In this way, although the DCI needs to be changed, since the lower layer is adjusted, the enhanced uplink DMRS is implemented, and at the same time, the configuration can be more flexibly performed in response to the change of the system, so that the allocation of subcarriers is more optimized.

In certain embodiments, in response to IFDMA being enabled, first terminal device 110 may parse the DCI to determine the subcarriers for first terminal device 110 to perform the uplink DMRS transmission. As shown above, schemes of indicating allocated subcarriers may be classified into two types.

In some embodiments, the first terminal device 110 parsing the DCI to determine the subcarriers may include: a cyclic shift field is parsed out in the DCI, and information in the cyclic shift field is used to specify that the first terminal device 110 is assigned odd numbered subcarriers and the second terminal device 120 is assigned even numbered subcarriers, or that the first terminal device 110 is assigned even numbered subcarriers and the second terminal device 120 is assigned odd numbered subcarriers.

In some embodiments, in response to IFDMA being enabled, first end device 110 may parse the extension bit of the cyclic shift field of the DCI to determine whether IFDMA is enabled.

It should be understood that the operations and related features performed by the network device 150 described above in conjunction with the schematic diagrams of fig. 3 to fig. 5 are also applicable to the method 600 performed by the first terminal device 110, and have the same effects, and detailed details are not described again.

Fig. 7 illustrates a block diagram of an apparatus 700 according to certain embodiments of the present disclosure. It is to be appreciated that the apparatus 700 may be implemented on the network device 150 side shown in fig. 1 and 2. As shown in fig. 7, an apparatus 700 (e.g., network device 150) includes: a determining unit 705 configured to determine whether IFDMA is enabled for transmission of an uplink DMRS; a generating unit 710 configured to generate an indication of whether IFDMA is enabled; and a transmitting unit 715 configured to transmit an indication to at least one of the first terminal device 110, the second terminal device 120, the third terminal device 130, and the fourth terminal device 140 (e.g., the first terminal device 110).

In some embodiments, the generating unit 710 further includes creating a parameter of the RRC layer to indicate whether IFDMA is enabled.

In certain embodiments, the generating unit 710 further comprises generating DCI indicating whether IFDMA is enabled. In certain embodiments, generating the DCI includes generating the DCI to indicate subcarriers for the first terminal device 110 to perform the uplink DMRS transmission in response to IFDMA being enabled. In certain embodiments, generating the DCI to indicate the subcarriers comprises: creating a cyclic shift field in the DCI, information in the cyclic shift field specifying that the first terminal device 110 is allocated odd numbered subcarriers and the second terminal device 120 is allocated even numbered subcarriers, or that the first terminal device 110 is allocated even numbered subcarriers and the second terminal device 120 is allocated odd numbered subcarriers; and the same Orthogonal Cover Code (OCC) is allocated to the first terminal device 110 and the second terminal device 120.

In certain embodiments, generating the DCI comprises: an extension bit of a cyclic shift field of the DCI is used to indicate whether IFDMA is enabled. In some embodiments, the extension bit is ignored in response to the DCI being transmitted.

Fig. 8 illustrates a block diagram of an apparatus 800 according to certain embodiments of the present disclosure. It is understood that the apparatus 800 may be implemented on the side of the first terminal device 110 shown in fig. 1 and 2. As shown, the apparatus 800 (e.g. the first terminal device 110, and also the second terminal device 120, the third terminal device 130, and the fourth terminal device 140 shown in fig. 1) includes: an indication receiving unit 805 configured to receive an indication of whether IFDMA is enabled from the network device 150; a signal parsing unit 810 configured to parse the indication to determine a transmission mode of the uplink DMRS.

In some embodiments, the indication parsing unit 810 further comprises parsing a parameter created by the RRC layer to indicate whether IFDMA is enabled.

In certain embodiments, the indication parsing unit 810 further includes parsing DCI indicating whether IFDMA is enabled. In certain embodiments, parsing the DCI includes parsing the DCI to determine subcarriers for the first terminal device 110 to perform the uplink DMRS transmission in response to IFDMA being enabled. In certain embodiments, parsing the DCI to determine the subcarriers comprises: a cyclic shift field is parsed out in the DCI, and information in the cyclic shift field is used to specify that the first terminal device 110 is allocated odd numbered subcarriers and the second terminal device 120 is allocated even numbered subcarriers, or that the first terminal device 110 is allocated even numbered subcarriers and the second terminal device 120 is allocated odd numbered subcarriers, wherein the first terminal device 110 and the second terminal device 120 are allocated the same Orthogonal Cover Code (OCC).

In certain embodiments, parsing the DCI comprises: an extension bit of a cyclic shift field of the DCI is parsed to determine whether IFDMA is enabled. In some embodiments, the extension bit is ignored in response to the DCI being parsed.

It should be understood that each unit recited in the apparatus 700 and the apparatus 800 corresponds to each step in the

methods

300 and 600 described with reference to fig. 1-6, respectively. Therefore, the operations and features described above in connection with fig. 1 to 6 are equally applicable to the apparatus 700 and the apparatus 800 and the units included therein, and have the same effects, and detailed details are not repeated.

The units included in the apparatus 700 and the apparatus 800 may be implemented in various ways, including software, hardware, firmware, or any combination thereof. In one embodiment, one or more of the units may be implemented using software and/or firmware, such as machine executable instructions stored on a storage medium. In addition to, or in the alternative to, machine-executable instructions, some or all of the elements in apparatus 700 and apparatus 800 may be implemented, at least in part, by one or more hardware logic components. By way of example, and not limitation, exemplary types of hardware logic components that may be used include Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Application Specific Standards (ASSPs), systems on a chip (SOCs), Complex Programmable Logic Devices (CPLDs), and so forth.

The elements shown in fig. 7 and 8 may be implemented partially or wholly as hardware modules, software modules, firmware modules, or any combination thereof. In particular, in some embodiments, the procedures, methods or processes described above may be implemented by hardware in a base station or a terminal device. For example, a base station or terminal device may implement

methods

300 and 600 using its transmitter, receiver, transceiver, and/or processor or controller.

Fig. 9 illustrates a block diagram of a device 900 suitable for implementing embodiments of the present disclosure. Device 900 may be used to implement a network device, such as network device 150 shown in fig. 1 and 2; and/or to implement a terminal device, such as the first terminal device 110 shown in fig. 1 and 2.

As shown, the device 900 includes a controller 910. The controller 910 controls the operation and functions of the device 900. For example, in certain embodiments, the controller 910 may perform various operations by way of instructions 930 stored in a memory 920 coupled thereto. The memory 920 may be of any suitable type suitable to the local technical environment and may be implemented using any suitable data storage technology, including but not limited to semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems. Although only a single memory unit is illustrated in FIG. 9, there may be multiple physically distinct memory units within device 900.

The controller 910 may be of any suitable type suitable to the local technical environment, and may include, but is not limited to, one or more of general purpose computers, special purpose computers, microcontrollers, digital signal controllers (DSPs), and controller-based multi-core controller architectures. The device 900 may also include a plurality of controllers 910. The controller 910 is coupled to a transceiver 940, and the transceiver 940 may enable receiving and transmitting information via one or more antennas 950 and/or other components.

When device 900 is acting as network device 150, controller 910 and transceiver 940 may operate in conjunction to implement method 300 described above with reference to fig. 3. When the device 900 is acting as the first terminal device 110, the controller 910 and the transceiver 940 may operate in cooperation to implement the method 600 described above with reference to fig. 6. For example, in certain embodiments, all acts described above relating to data/information transceiving may be performed by the transceiver 940, while other acts may be performed by the controller 910. All of the features described above with reference to fig. 3 and 6 apply to the device 900 and are not described in detail herein.

In general, the various example embodiments of this disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Certain aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While aspects of embodiments of the disclosure have been illustrated or described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

By way of example, implementations of the disclosure may be described in the context of machine-executable instructions, such as program modules, being included in a device executing on a target real or virtual processor. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or divided between program modules as described. Machine-executable instructions for program modules may be executed within local or distributed devices. In a distributed facility, program modules may be located in both local and remote memory storage media.

Computer program code for implementing the methods of the present disclosure may be written in one or more programming languages. These computer program codes may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the computer or other programmable data processing apparatus, cause the functions/acts specified in the flowchart and/or block diagram block or blocks to be performed. The program code may execute entirely on the computer, partly on the computer, as a stand-alone software package, partly on the computer and partly on a remote computer or entirely on the remote computer or server.

In the context of this disclosure, a machine-readable medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More detailed examples of a machine-readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical storage device, a magnetic storage device, or any suitable combination thereof.

Additionally, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking or parallel processing may be beneficial. Likewise, while the above discussion contains certain specific implementation details, this should not be construed as limiting the scope of any invention or claims, but rather as describing particular embodiments that may be directed to particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A method of communication, comprising:

determining, at a network device, whether Interleaved Frequency Division Multiple Access (IFDMA) is enabled for transmission of an uplink demodulation reference signal (DMRS);

generating an indication of whether the IFDMA is enabled; and

the indication is sent to the terminal device,

wherein in response to the indication indicating that the IFDMA is enabled, the terminal device and another terminal device allocated the same Orthogonal Cover Code (OCC) are configured to transmit uplink demodulation reference signals (DMRS) on even numbered subcarriers and odd numbered subcarriers, respectively.

2. The method of claim 1, wherein generating the indication of whether the IFDMA is enabled comprises:

a parameter of a Radio Resource Control (RRC) layer is created to indicate whether IFDMA is enabled.

3. The method of claim 1, wherein generating the indication of whether the IFDMA is enabled comprises:

generating Downlink Control Information (DCI) indicating whether the IFDMA is enabled.

4. The method of claim 3, wherein generating the DCI comprises:

in response to the IFDMA being enabled, generating the DCI to indicate subcarriers for the terminal device to perform the uplink DMRS transmission.

5. The method of claim 4, wherein generating the DCI to indicate the subcarriers comprises:

creating a cyclic shift field in the DCI, information in the cyclic shift field specifying that the terminal device is allocated odd numbered subcarriers and another terminal device is allocated even numbered subcarriers, or that the terminal device is allocated even numbered subcarriers and the another terminal device is allocated odd numbered subcarriers; and

allocating the same Orthogonal Cover Code (OCC) to the terminal device and the other terminal device.

6. The method of claim 3, wherein generating the DCI comprises:

indicating whether the IFDMA is enabled using an extension bit of a cyclic shift field of the DCI.

7. The method of claim 6, wherein the extension bit is ignored in response to the DCI being transmitted.

8. A method of communication, comprising:

receiving, at a terminal device, an indication from a network device whether Interleaved Frequency Division Multiple Access (IFDMA) is enabled; and

parse the indication to determine a transmission mode for an uplink demodulation reference signal (DMRS),

9. The method of claim 8, wherein resolving the indication comprises:

a parameter created by a Radio Resource Control (RRC) layer is parsed to indicate whether IFDMA is enabled.

10. The method of claim 8, wherein resolving the indication comprises:

parsing Downlink Control Information (DCI) indicating whether the IFDMA is enabled.

11. The method of claim 10, wherein parsing the DCI comprises:

in response to the IFDMA being enabled, parsing the DCI to determine subcarriers for the terminal device to perform the uplink DMRS transmission.

12. The method of claim 11, wherein parsing the DCI to determine the subcarriers comprises:

and analyzing a cyclic shift domain in the DCI, wherein the information in the cyclic shift domain is used for specifying that the terminal equipment is allocated with the sub-carrier with the odd number and the other terminal equipment is allocated with the sub-carrier with the even number, or the terminal equipment is allocated with the sub-carrier with the even number and the other terminal equipment is allocated with the sub-carrier with the odd number.

13. The method of claim 10, wherein parsing the DCI comprises:

parsing an extension bit of a cyclic shift field of the DCI to determine whether the IFDMA is enabled.

14. The method of claim 13, wherein the extension bit is ignored in response to the DCI being parsed.

15. A network device, comprising:

a controller configured to determine whether Interleaved Frequency Division Multiple Access (IFDMA) is enabled for transmission of an uplink demodulation reference signal (DMRS), and to generate an indication of whether the IFDMA is enabled; and

a transceiver configured to transmit the indication to a terminal device,

16. The network device of claim 15, wherein generating the indication of whether the IFDMA is enabled comprises:

17. The network device of claim 15, wherein generating the indication of whether the IFDMA is enabled comprises:

18. The network device of claim 17, wherein generating the DCI comprises:

19. The network device of claim 18, wherein generating the DCI to indicate the subcarriers comprises:

creating a cyclic shift field in the DCI, information in the cyclic shift field specifying that the terminal device is allocated odd numbered subcarriers and the other terminal device is allocated even numbered subcarriers, or that the terminal device is allocated even numbered subcarriers and the other terminal device is allocated odd numbered subcarriers; and

20. The network device of claim 17, wherein generating the DCI comprises:

21. The network device of claim 20, wherein the extension bit is ignored in response to the DCI being transmitted.

22. A terminal device, comprising:

a transceiver configured to receive an indication of whether Interleaved Frequency Division Multiple Access (IFDMA) is enabled from a network device; and

a controller configured to parse the indication to determine a transmission mode of an uplink demodulation reference signal (DMRS),

23. The terminal device of claim 22, wherein resolving the indication comprises:

24. The terminal device of claim 22, wherein resolving the indication comprises:

25. The terminal device of claim 24, wherein parsing the DCI comprises:

26. The terminal device of claim 25, wherein parsing the DCI to determine the subcarriers comprises:

27. The terminal device of claim 24, wherein parsing the DCI comprises:

28. The terminal device of claim 27, wherein the extension bit is ignored in response to the DCI being parsed.