CN107370532B

CN107370532B - Communication method, base station device and communication device in communication system

Info

Publication number: CN107370532B
Application number: CN201610317127.5A
Authority: CN
Inventors: 武卓; 王钧; 沈钢
Original assignee: Nokia Shanghai Bell Co Ltd
Current assignee: Nokia Shanghai Bell Co Ltd
Priority date: 2016-05-12
Filing date: 2016-05-12
Publication date: 2021-04-06
Anticipated expiration: 2036-05-12
Also published as: CN107370532A; WO2017195040A1

Abstract

The present disclosure provides a method and apparatus for supporting multi-user stacked transmission in a communication system, wherein a base station of the communication system pairs a near-end UE with a far-end UE for multi-user stacked transmission. The method comprises the following steps: setting the DCI to include transmission indication information indicating whether transmission of one subframe is multi-user stacked transmission; in response to the transmission indication information indicating that the transmission of the subframe is multi-user stacked transmission, setting a downlink pairing control message to include an NAI of a far-end UE paired with the near-end UE, the NAI including at least superimposed constellation information for indicating power allocation information of a spatial layer between the near-end UE and the far-end UE; and sending downlink pairing control information to the near-end UE.

Description

Communication method, base station device and communication device in communication system

Technical Field

The present invention relates generally to the field of wireless communication, and more particularly, to a communication method, a base station apparatus and a communication apparatus implemented by a base station or a near-end UE in a communication system.

Background

Recently, the third generation partnership project (3GPP) has approved a work item for Downlink (DL) multi-user overlay Transmission (MUST), the objective of which is to determine the necessary mechanisms to support downlink intra-cell multi-user overlay Transmission of a Physical Downlink Shared Channel (PDSCH) with assistance information from the serving base station to the User Equipment (UE) regarding the inter-cell interference it experiences. The following is considered for DL multi-user stacked transmission: transmitting the superimposed PDSCH using the same transmission scheme and the same spatial precoding vector; transmitting the superimposed PDSCH using the same transmit diversity scheme; and transmitting the superimposed PDSCH using the same transmission scheme, but with different spatial precoding vectors.

Multi-user overlay transmission has generally proven to be more advantageous when the network experiences higher traffic loads. In this case, more UE pairs can be used for multi-user stacked transmission, which will result in more system capacity increase. Therefore, the near-end UE and the far-end UE that should support multi-user stacked transmission in multi-user stacked transmission are dynamically paired on different spatial layers and subbands by one subframe and one subframe, for example, the near-end UE and the far-end UEs of one multi-user stacked transmission are paired on different spatial layers or in different subbands to increase the probability of pairing of multi-user stacked transmission.

Disclosure of Invention

However, the dynamic pairing of the near-end UE and the far-end UE in the multi-user stacked transmission and the dynamic switching between the multi-user stacked transmission and the non-multi-user stacked transmission will generate huge signaling overhead and decoding complexity. To address the above and other potential problems, embodiments of the present disclosure propose a method and apparatus for supporting multi-user stacked transmission in a communication system.

In a first aspect of the present disclosure, a method for supporting multi-user stacked transmission in a communication system whose base station pairs a near-end UE with a far-end UE for the multi-user stacked transmission is provided, the method comprising: setting the DCI to include transmission indication information indicating whether transmission of one subframe is multi-user stacked transmission; in response to the transmission indication information indicating that the transmission of the subframe is multi-user stacked transmission, setting a downlink pairing control message to include an NAI of a far-end UE paired with the near-end UE, the NAI including at least superimposed constellation information for indicating power allocation information of a spatial layer between the near-end UE and the far-end UE; and sending the downlink pairing control information to the near-end UE.

In a second aspect of the present disclosure, there is provided a method for supporting multi-user stacked transmission in a communication system, a base station of the communication system pairing a near-end UE and a far-end UE for multi-user stacked transmission, the method comprising, at one near-end UE: receiving a transmission on a subband or PRB from the base station; determining whether a transmission on the subband or PRB is a multi-user stacked transmission by determining whether there is interference on the subband or PRB; in response to determining that the transmission on the subband or PRB is multi-user stacked transmission, acquiring a downlink pairing control message from the search space, where the downlink pairing control message includes an NAI of at least one far-end UE, and the NAI includes superimposed constellation information for indicating power allocation information of each spatial layer between the near-end UE and the at least one far-end UE.

In a third aspect of the present invention, there is provided a base station apparatus that pairs a near-end UE and a far-end UE for multi-user stacked transmission, the base station apparatus including: a processor and a memory, the memory comprising instructions executable by the processor, the processor being configured to cause the base station apparatus to perform a method according to the first aspect of the present disclosure.

In a fourth aspect of the present invention, there is provided a communication apparatus paired with a far-end UE by a base station of a communication system so as to function as a near-end UE in multi-user stacked transmission, the communication apparatus comprising: a processor and a memory, the memory including instructions executable by the processor, the processor being configured to cause the communication device to perform a method according to the second aspect of the disclosure.

Drawings

The present disclosure will be better understood and other objects, details, features and advantages thereof will become more apparent from the following description of specific embodiments of the present disclosure, which is given by reference to the following drawings. In the drawings:

fig. 1 shows a schematic diagram of a case of multi-user stacked transmission in a communication system;

fig. 2 shows a flow diagram of a method for supporting multi-user stacked transmission in a communication system according to an embodiment of the present disclosure;

fig. 3 shows a schematic diagram of a pairing situation of a near-end UE and a far-end UE according to an embodiment of the present disclosure;

fig. 4 shows a flow diagram of a method for supporting multi-user stacked transmission in a communication system according to an embodiment of the present disclosure;

fig. 5A and 5B show schematic diagrams of examples of candidate remote UEs to be blind-checked according to an embodiment of the present disclosure;

fig. 6 illustrates a block diagram of an apparatus for supporting multi-user stacked transmission in a communication system according to an embodiment of the present disclosure;

fig. 7 illustrates a block diagram of an apparatus for supporting multi-user stacked transmission in a communication system according to an embodiment of the present disclosure; and

fig. 8 illustrates a block diagram of an apparatus suitable for implementing embodiments of the present disclosure.

Detailed Description

Preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Fig. 1 shows a schematic diagram of a case of multi-user stacked transmission in a communication system 100. As shown in fig. 1, the communication system 100 includes a base station (eNB)110, a UE120, and a UE 130, and the base station 110 pairs the UE120 and the UE 130 for multi-user stacked transmission. Herein, when performing multi-user stacked transmission, a UE closer to a base station among paired UEs is referred to as a near-end UE or a MUST near-end UE, such as UE120 in fig. 1; while UEs farther away from the base station are referred to as far-end UEs or MUST far-end UEs, such as UE 130 in fig. 1.

In multi-user stacked transmission, the base station allocates a larger transmit power to the far-end UE 130, and a relatively smaller transmit power to the near-end UE 120. Upon receiving a DL multi-user stacked transmission from the base station, the near-end UE120 first decodes the signal directed to the far-end UE 130 from the received transmission, then removes the signal of the far-end UE 130 from the received transmission, and finally decodes the data directed to itself from the remaining transmissions. In fig. 1, the multi-user stacked transmission is illustrated by only one near-end UE and one far-end UE as an example, however, it can be understood by those skilled in the art that the case of UE pairing in the multi-user stacked transmission also includes pairing one near-end UE with multiple far-end UEs, pairing multiple near-end UEs with one far-end UE, and pairing multiple near-end UEs with multiple far-end UEs.

Dynamic pairing of the MUST near-end UE and the MUST far-end UE on a sub-frame-by-sub-frame basis across different spatial layers and sub-bands increases the likelihood of MUST pairing. However, this dynamic pairing, and the resulting dynamic switching of multi-user stacked transmission and non-multi-user stacked transmission with different subframes, makes it difficult to detect the signals of paired MUST far-end UEs at the MUST near-end UEs. This is especially true when multiple MUST far-end UEs are paired with one MUST near-end UE and the pairing is different from subframe to subframe. Although it has been proposed to help decode the signals of the MUST far-end UE at the MUST near-end UE by determining some candidate parameters for the assistance information and blindly detecting other parameters, transmitting the determined candidate parameters by higher layer signaling at long time intervals will not provide the necessary assistance information for the MUST far-end UE, which is updated at every subframe.

Meanwhile, blind detection of all parameters of paired MUST remote UEs in each subframe would generate too much decoding complexity and be very time consuming, difficult to support dynamic pairing/handover in multi-user stacked transmission. Also, notifying the MUST near-end UE of all Downlink Control Information (DCI) of paired MUST far-end UEs would bring too much signaling overhead, which would get worse if multiple MUST far-end UEs were paired with the same MUST near-end UE.

Embodiments of the present disclosure propose an enhanced DCI format design and corresponding decoding signaling to support dynamic pairing with wideband scheduling or subband scheduling in DL multi-user stacked transmission. For example, one MUST near UE is supported to be paired with multiple MUST far UEs, or one MUST far UE is supported to be paired with multiple MUST near UEs. Furthermore, dynamic switching between subframes for multi-user stacked transmission and non-multi-user stacked transmission is supported.

Fig. 2 shows a flow diagram of a method 200 for supporting multi-user stacked transmission in a communication system according to an embodiment of the disclosure. The method 200 may be implemented for the near-end UE120, for example, at a base station (e.g., base station 110 shown in fig. 1) side of a communication system.

In step 210, the base station 110 sets Downlink Control Information (DCI) to include transmission indication information. The transmission indication information indicates whether transmission of one subframe is multi-user stacked transmission.

As described above, dynamic signaling is required at the MUST near-end UE to determine whether its receiver detects the received signal as a superposition transmission (multi-user superposition transmission) or a single transmission (non-multi-user superposition transmission), and therefore, this additional transmission indication information is appended in the DCI to indicate to the near-end UE whether the received transmission of each DL subframe is a multi-user superposition transmission.

In some implementations, the transmission indication information may be one extra bit appended to the current DCI format. For example, a bit of 0 indicates that the transmission of the subframe is a non-multiuser stacked transmission (i.e., a single transmission), and a bit of 1 indicates that the transmission of the subframe is a multiuser stacked transmission; or vice versa. Of course, any other form of indication is possible, and the scope of the disclosure is not limited in this respect.

In step 220, in case that the transmission indication Information indicates that the transmission of the subframe is multi-user stacked transmission, the base station 110 sets a downlink pairing control message to include Necessary Assistance Information (NAI) of the far-end UE paired with the near-end UE 120. The NAI of each remote UE may be indicated using any number of bits, e.g., 5-8 bits.

By including only the NAI of the paired far-end UE in the downlink pairing message instead of all the DCI of the far-end UE, the near-end UE is enabled to detect the signal of the far-end UE without having to decode all the DCI of the far-end UE. In this way, the signaling overhead of the system and the decoding overhead of the near-end UE are effectively reduced.

In particular, according to an embodiment of the present disclosure, the NAI of the paired far-end UE includes at least superimposed constellation information for indicating power allocation information between the paired near-end UE and far-end UE at a spatial layer. For example, in some embodiments, the constellation information may indicate the power allocation of the near-end UE and the far-end UE in each spatial layer.

Fig. 3 shows a schematic diagram of a pairing situation of a near-end UE and a far-end UE according to an embodiment of the present disclosure. As shown in fig. 3, near UE #1 is paired with far UE #1 and far UE #2 (referred to as MUST pair 1), near UE #2 and near UE #3 is paired with far UE #3 (referred to as MUST pair 2), and near UE #4 is paired with far UE #4 (referred to as MUST pair 3). The power allocation between the paired near and far end UEs is shown on the vertical axis in fig. 2, which is indicated by the superimposed constellation information included in the NAI.

In some implementations, in response to the far-end UE supporting a modulation scheme other than Quadrature Phase Shift Keying (QPSK), the setting of the downlink pairing control message at step 220 may include including in the NAI a modulation order indicating the modulation scheme of the paired far-end UE. In this way, the scheme of the present disclosure can be flexibly applied to different scenarios where the near-end UE and the far-end UE use the same or different modulation schemes.

Alternatively or additionally, in some implementations, if the far-end UE uses a different decoder than the near-end UE, the setting of the downlink pairing control message may also include including a Precoding Matrix Indication (PMI) index in the NAI in step 220. The PMI index indicates a precoding scheme of the paired remote UE. As an example, for a codebook-based precoding scheme (e.g., Transmission Mode (TM)4), the PMI index may include 2 or 4 bits.

On the other hand, according to embodiments of the present disclosure, the downlink pairing control message may be set as one separate control message independent of the current DCI or as one part of the current DCI.

In some implementations, when one far-end UE is paired with multiple near-end UEs in one subframe (as shown by MUST pair 2 in fig. 3), the base station 110 sets the downlink pairing control message as a separate control message independent of the current DCI, the separate control message including NAIs of all far-end UEs paired with near-end UEs in one subframe. In some implementations, the format of the individual control messages formed may be similar to the current DCI format 3/3 a. For example, the format of the separate control message may be:

NAI 1、NAI 2、……、NAI N

where N represents a total number of far-end UEs having a pairing relationship with a plurality of near-end UEs in the scheduled subframe.

In other implementations, one far-end UE may be paired with only one near-end UE in one subframe. This includes, for example, one near UE paired with only one far UE, as shown by the MUST pair 3 in fig. 3; it may also include the case where one near UE is paired with multiple far UEs, as shown in the MUST pair 1 in fig. 3. In this case, the base station 110 may set the downlink pairing control message to include only the NAI of the far-end UE paired with one near-end UE. At this time, the downlink pairing control message may be included into the current DCI as a part thereof. In this way, the near-end UE that receives the DCI including the downlink pairing control message can detect a signal of the paired far-end UE after decoding the DCI of the near-end UE itself.

In step 230, the base station 110 sends the downlink pairing control message to the near-end UE 120. In some implementations, when the downlink pairing control message is set as a separate control message, the downlink pairing control message is transmitted to the near-end UE120 in a Physical Downlink Control Channel (PDCCH). In this case, the near-end UE120 may obtain the NAI of the far-end UE by monitoring the Common Search Space (CSS).

In other implementations, the downlink pairing control message is sent to the near-end UE120 in PDCCH or enhanced PDCCH when the downlink pairing control message is set as part of the current DCI. In this case, the near-end UE120 may obtain the NAI of the far-end UE paired therewith by monitoring the UE-specific search space (USS).

Fig. 4 shows a flow diagram of a method 400 for supporting multi-user stacked transmission in a communication system according to an embodiment of the disclosure. The method 400 may be implemented, for example, at a near-end UE of a communication system, such as the UE120 shown in fig. 1. That is, the base station and the near-end UE in the communication system may cooperatively implement the

methods

200 and 400 to implement various embodiments of the present disclosure.

At step 410, the near-end UE120 receives a transmission on one subband or Physical Resource Block (PRB) from the base station 110. Next, at step 420, the near-end UE120 determines whether the transmission on the subband or PRB is a multi-user stacked transmission by determining whether there is interference on the subband or PRB.

If the interference level on that subband or PRB is high, e.g., above a certain threshold, the near-end UE120 may determine the transmission as a multi-user stacked transmission. Conversely, if the interference level on the subband or PRB is low, e.g., below the certain threshold, the near-end UE120 may determine the transmission as a non-multi-user stacked transmission. This is because, as previously mentioned, the multi-user stacked transmission contains data for the paired near-end UE and far-end UE, and the transmit power for the far-end UE is typically higher. Therefore, data transmission of the far-end UE may become interference of the near-end UE, and its interference level is generally high. Those skilled in the art will appreciate that the particular thresholds herein may be configured according to channel conditions or traffic conditions without affecting the scope of the present disclosure.

At step 430, if the near-end UE120 determines that the transmission on the subband or PRB is a multi-user stacked transmission, the near-end UE120 may obtain a downlink pairing control message from a search space (e.g., CSS and/or USS). The downlink pairing control message includes the NAI of the at least one remote UE. The NAI includes at least superimposed constellation information indicating power allocation information on each spatial layer between the near-end UE120 and the at least one far-end UE, as described above.

If one far-end UE is paired with multiple near-end UEs, each near-end UE can obtain the NAI of the far-end UE by monitoring the common search space. Under the condition of a blind detection rule specified in the current 3GPP standard, NAI of the remote UE is detected in a blind way by monitoring a common search space, and the NAI is carried in a PDCCH region only corresponding to a downlink pairing control message. That is, if one far-end UE is paired with a plurality of near-end UEs, the NAI of the far-end UE is included in a separate control message to be transmitted through the PDCCH, and the receiving side obtains the NAI of the far-end UE by blindly checking the common search space. In this case, the near-end UE120 monitors the downlink pairing control message at

aggregation levels

4 and 8 in addition to monitoring the DCI of the near-end UE120 itself from the common search space.

If one near-end UE is paired with multiple far-end UEs or one far-end UE is paired with only one near-end UE, each near-end UE can obtain the NAI of the far-end UE paired with it by monitoring the UE-specific search space. Under the condition of a blind detection rule specified in the current 3GPP standard, NAI of a remote UE is detected in a blind manner by monitoring a specific search space of the UE and is carried in a PDCCH or EPDCCH region corresponding to a downlink pairing control message. That is, if one near-end UE is paired with one or more far-end UEs, the NAI of the one or more far-end UEs is transmitted through PDCCH or EPDCCH as an additional part of the current DCI, and the receiving side obtains the NAI of the one or more far-end UEs by blindly detecting the UE-specific search space.

In some implementations, the downlink pairing control message is carried in a PDCCH, and NAIs of one or more far-end UEs paired with the near-end UE are appended to the current content of DCI of the near-end UE itself.

In other implementations, if the near-end UE is configured to have an EPDCCH in its Physical Downlink Shared Channel (PDSCH) region, the downlink pairing control message may be carried in the EPDCCH, and the NAIs of one or more far-end UEs paired with the near-end UE are appended to the current content of the DCI of the near-end UE itself.

The near-end UE may monitor the UE-specific search space and perform Cyclic Redundancy Check (CRC) scrambling in the PDCCH/EPDCCH region, e.g., using a cell radio network temporary identity (C-RNTI), to determine the NAI of the paired far-end UE. In this implementation, since the DCI includes the NAI of the paired far-end UEs (the NAI of each far-end UE is represented by 5-8 bits, for example), so that the DCI is larger than the size of the DCI defined in the current standard, more candidate Channel Control Elements (CCEs) are required for the near-end UE to perform blind detection. However, the additional blind detection complexity of decoding only the NAI of the remote UE is much lower than the decoding complexity required to decode the full DCI of the remote UE.

Once the NAI of the paired remote UE is decoded in the PDCCH/EPDCCH region, the number of candidate remote UEs has been greatly reduced, although the resource allocation of the remote UE is not yet known by the near UE. Therefore, when the control information of the far-end UE is detected in a blind mode at the near-end UE, only a small number of decoding attempts are needed, so that quick blind detection is achieved, and the decoding complexity is greatly reduced.

Fig. 5A and 5B show schematic diagrams of examples of candidate remote UEs to be blind-checked according to an embodiment of the present disclosure. Referring again to fig. 3, it can be seen that the far-end UE #3 is paired with multiple near-end UEs (MUST pair 2 in fig. 3), so the NAI of the far-end UE #3 and other candidate far-end UEs paired with the multiple near-end UEs form an independent downlink pairing control message. The far-end UE #1 and the far-end UE #2 are paired only with the near-end UE #1, and therefore downlink pairing control messages formed by their NAIs are appended to the DCI of the near-end UE # 1. The far-end UE #4 is paired only with the near-end UE #4, and therefore a downlink pairing control message formed by its NAI is appended to the DCI of the near-end UE # 4.

Therefore, as shown in fig. 5A, when the near-end UE #1 performs blind detection of control information of the far-end UE, the near-end UE #1 acquires NAIs of the far-end UE #1 and the far-end UE #2 by blind-detecting NAIs of the far-end UE #3 by monitoring a common search space on, for example, the convergence level 4 and the convergence level 8, and monitoring its own UE-specific search space.

After the near-end UE #1 obtains the NAIs of the candidate far-end UEs #1, #2, and #3 from the common search space and its own UE-specific search space, the near-end UE #1 only needs to make decoding attempts among the far-end UE #1, the far-end UE #2, and the far-end UE #3 when decoding the PDSCH of its paired far-end UE.

For near end UE #2 and near end UE #3, since they are paired only with the same far end UE #3, near end UE #2 and near end UE #3 only monitor the common search space to obtain the NAI of far end UE #3, and only need to make a decoding attempt for far end UE #3 when decoding the PDSCH of its paired far end UE.

Similar to the near-end UE #1, as shown in fig. 5B, the near-end UE #4 acquires the NAI of the far-end UE #4 by blindly detecting the NAI of the far-end UE #3 by monitoring the common search space and monitoring its own UE-specific search space. After the near-end UE #4 obtains the NAIs of the candidate far-end UEs #3 and #4 from the common search space and its own UE-specific search space, the near-end UE #4 only needs to make a decoding attempt between the far-end UE #3 and the far-end UE #4 when decoding the PDSCH of its paired far-end UE.

In some implementations, after step 420 and before step 430, method 400 may further include: the near-end UE120 acquires transmission indication information from the DCI sent by the base station 110, where the transmission indication information indicates whether transmission of one subframe is multi-user stacked transmission.

In this case, after step 430, method 400 may further include the following actions (not shown in the figure): if the transmission of the subframe is a multi-user stacked transmission, the near-end UE120 performs a decoding attempt on the multi-user stacked transmission only for the blind-detected far-end UE (i.e., candidate far-end UE) to decode a signal of a far-end UE paired with the near-end UE120 from the multi-user stacked transmission. Next, the near-end UE120 may remove the decoded signal of the far-end UE from the multi-user stacked transmission, resulting in a signal for the near-end UE 120.

Fig. 6 illustrates a block diagram of an apparatus 600 for supporting multi-user stacked transmission in a communication system according to an embodiment of the disclosure. The apparatus 600 may be implemented in or by a base station of a communication system, such as the base station 110 shown in fig. 1, for example.

As shown in fig. 6, the apparatus 600 includes a DCI setting unit 610 configured to set DCI to include transmission indication information indicating whether transmission of one subframe is multi-user stacked transmission. The apparatus 600 further includes an NAI setting unit 620 configured to set, in response to the transmission indication information indicating that the transmission of the subframe is a multi-user stacked transmission, a downlink pairing control message to include an NAI of a far-end UE paired with the near-end UE, the NAI including at least superimposed constellation information for indicating power allocation information between the near-end UE and the far-end UE at a spatial layer. The apparatus 600 further includes a transmitting unit 630 configured to transmit the downlink pairing control information to the near-end UE.

In some implementations, the NAI setup unit 620 is further configured to include in the NAI a modulation order indicating a modulation scheme of the far-end UE in response to the far-end UE supporting a modulation scheme other than QPSK.

In some implementations, the NAI setting unit 620 is further configured to include a PMI index in the NAI for indicating a precoding scheme of the far-end UE, in response to the far-end UE using a different precoder than the near-end UE.

In some implementations, the NAI setting unit 620 is further configured to set the downlink pairing control message to include NAIs of a plurality of far-end UEs paired with a plurality of near-end UEs independently of DCI in response to one far-end UE paired with the plurality of near-end UEs in the subframe.

In some implementations, the NAI setup unit 620 is further configured to send the downlink pairing control message to the near-end UE in a PDCCH.

In some implementations, the NAI setting unit 620 is further configured to set the downlink pairing control message to include only the NAI of the far-end UE paired with the one near-end UE and include the downlink pairing control message into the DCI as a part thereof, in response to the one far-end UE being paired with only one near-end UE in the subframe.

In some implementations, the NAI setting unit 620 is further configured to transmit a downlink pairing control message to the near-end UE in at least one of PDCCH and EPDCCH.

Fig. 7 illustrates a block diagram of an apparatus 700 for supporting multi-user stacked transmission in a communication system according to an embodiment of the disclosure. The apparatus 700 may be implemented in or by a near-end UE of a communication system, such as the near-end UE120 shown in fig. 1, for example.

As shown in fig. 7, apparatus 700 may include a receiving unit 710 configured to receive a transmission on one subband or PRB from a base station. The apparatus 700 may also include a transmission determination unit 720 to determine whether a transmission on the subband or PRB is a multi-user stacked transmission by determining whether there is interference on the subband or PRB. Apparatus 700 may also include a NAI acquisition unit 730 configured to acquire a downlink pairing control message from the search space in response to determining that the transmission on the subband or PRB is a multi-user stacked transmission. The downlink pairing control message includes an NAI of the at least one far-end UE, the NAI including superimposed constellation information for indicating power allocation information of each spatial layer between the near-end UE and the at least one far-end UE.

In some implementations, the apparatus 700 further includes: a DCI acquiring unit (not shown) configured to acquire transmission indication information indicating whether transmission of one subframe is multi-user stacked transmission from DCI.

In some implementations, the apparatus 700 further includes a decoding unit (not shown) configured to, in response to the transmission indication information indicating that the transmission of the subframe is a multi-user stacked transmission, attempt to decode the multi-user stacked transmission only for the at least one far-end UE to decode, from the multi-user stacked transmission, a signal of a far-end UE of the at least one far-end UE paired with the near-end UE; and the decoding unit is further configured to remove a signal of a far-end UE paired with a near-end UE from the multi-user stacked transmission to obtain a signal for the near-end UE.

It should be appreciated that each of the

apparatus

600 and 700 shown in fig. 6 and 7 may be implemented, in part or in whole, by software modules, hardware modules, firmware modules, or any combination thereof, as the scope of the present invention is not limited in this respect. For example, in a hardware-based implementation, one or more of the units described above may be implemented using a hardware device such as an Integrated Circuit (IC), an Application Specific Integrated Circuit (ASIC), a system on a chip (SOC), a Field Programmable Gate Array (FPGA), or the like.

Fig. 8 illustrates a block diagram of a device 800 suitable for implementing embodiments of the present disclosure. Apparatus 200 may be used to implement a base station apparatus, such as base station 110 shown in fig. 1, or a user communication apparatus acting as a near-end UE in a multi-user stacked transmission, such as near-end UE120 shown in fig. 1.

As shown in fig. 8, device 800 includes a processor 810 and a memory 820 coupled to processor 410. The memory 820 stores instructions 830 that may be executed by the processor 810. The memory 820 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 one memory unit is shown in FIG. 8, there may be multiple physically distinct memory units within device 800.

The processor 810 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, microprocessors, Digital Signal Processors (DSPs) and processor-based multi-core processor architectures. The device 800 may also include multiple processors 810. The processor 810 is configured to perform the

method

200 or 400 as shown in fig. 2 or 4.

An enhanced dynamic control signaling design is presented herein to support dynamic pairing/switching of multi-user stacked transmissions. Only the necessary assistance information of the remote UE is included in the enhanced dynamic signaling instead of including all DCI, thereby minimizing signaling overhead. In addition, it is proposed to reduce the blind detection complexity of the control information of the remote UE by limiting the number of candidate remote UEs in the blind detection process.

In one or more exemplary designs, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer. Such computer-readable media can comprise, for example, but is not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code means in the form of instructions or data structures and which can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A communication method implemented by a base station in a communication system, the base station pairing a near-end user equipment, UE, with a far-end UE of the communication system for multi-user stacked transmission, the method comprising:

setting Downlink Control Information (DCI) to include transmission indication information, wherein the transmission indication information indicates whether transmission of one subframe is multi-user stacked transmission;

in response to the transmission indication information indicating that the transmission of the subframe is a multi-user stacked transmission, setting a downlink pairing control message to include Necessary Assistance Information (NAI) of a far-end UE paired with the near-end UE, the NAI including at least superimposed constellation information for indicating power allocation information between the near-end UE and the far-end UE in a spatial layer; and

and sending the downlink pairing control message to the near-end UE.

2. The method of claim 1, wherein setting the downlink pairing control message comprises:

in response to the far-end UE supporting a modulation scheme other than quadrature phase shift keying, including in the NAI a modulation order indicating a modulation scheme of the far-end UE.

3. The method of claim 1, wherein setting the downlink pairing control message comprises:

in response to the far-end UE using a different precoder than the near-end UE, including a Precoding Matrix Indication (PMI) index in the NAI for indicating a precoding scheme of the far-end UE.

4. The method of claim 1, wherein setting the downlink pairing control message comprises:

in response to one far-end UE being paired with a plurality of near-end UEs in the subframe, setting the downlink pairing control message to include NAIs of the plurality of far-end UEs paired with the plurality of near-end UEs, independently of the DCI.

5. The method of claim 4, wherein sending the downlink pairing control message to the near-end UE comprises:

and sending the downlink pairing control message to the near-end UE in a Physical Downlink Control Channel (PDCCH).

6. The method of claim 1, wherein setting the downlink pairing control message comprises:

in response to one far-end UE pairing with only one near-end UE in the subframe, setting the downlink pairing control message to include only the NAI of the far-end UE paired with the one near-end UE; and

including the downlink pairing control message into the DCI as a part thereof.

7. The method of claim 6, wherein sending the downlink pairing control message to the near-end UE comprises:

and sending the downlink pairing control message to the near-end UE in at least one of a physical downlink control channel PDCCH and an enhanced physical downlink control channel EPDCCH.

8. A communication method implemented by a near-end UE in a communication system whose base station pairs the near-end UE and a far-end UE for multi-user stacked transmission, the method comprising:

receiving a transmission on one subband or physical resource block, PRB, from the base station;

determining whether a transmission on the subband or PRB is a multi-user stacked transmission by determining whether interference is present on the subband or PRB;

in response to determining that the transmission on the subband or PRB is a multi-user stacked transmission, acquiring a downlink pairing control message from a search space, where the downlink pairing control message includes necessary assistance information NAI of at least one far-end UE, and the NAI includes at least superimposed constellation information for indicating power allocation information of each spatial layer between the near-end UE and the at least one far-end UE.

9. The method of claim 8, further comprising:

and acquiring transmission indication information from the downlink control information DCI, wherein the transmission indication information is used for indicating whether the transmission of one subframe is multi-user stacked transmission.

10. The method of claim 9, further comprising:

in response to the transmission indication information indicating that the transmission of the subframe is a multi-user stacked transmission, making a decoding attempt on the multi-user stacked transmission only for the at least one far-end UE to decode a signal of a far-end UE of the at least one far-end UE paired with the near-end UE from the multi-user stacked transmission; and

removing signals of the far-end UE paired with the near-end UE from the multi-user stacked transmission to obtain signals for the near-end UE.

11. A base station apparatus that pairs a near end user equipment, UE, with a far end UE for multi-user stacked transmission, the base station apparatus comprising:

a processor and a memory, the memory including instructions executable by the processor, the processor configured to cause the base station apparatus to perform the method of any of claims 1-7.

12. A communication device paired with a far-end user equipment, UE, by a base station of a communication system to act as a near-end UE in a multi-user stacked transmission, the communication device comprising:

a processor and a memory, the memory including instructions executable by the processor, the processor configured to cause the communication device to perform the method of any of claims 8-10.