Downlink data transmission method and apparatus, electronic device, and medium

Abstract

The application discloses a transmission method and device of downlink data, electronic equipment and medium. Through application of the technical solution of the application, in the case that the channel hardening condition is insufficient in a distributed multi-antenna system, the size relationship between the channel hardening ratio between a user equipment and an access point and a preset threshold is compared. Different downlink transmission methods are adopted for user equipments with different hardening ratios. Thus, on the one hand, a technical solution for adaptively obtaining the compromise between transmission performance and transmission overhead according to the actual channel propagation condition of the user equipment is realized. Furthermore, the purpose of reducing the pilot overhead and improving the spectral efficiency of downlink transmission under the premise of ensuring the transmission performance of the distributed multi-antenna system is achieved.

Description

Technical Field

[0001] This application relates to data processing technology, and in particular to a method, apparatus, electronic device and medium for transmitting downlink data. Background Technology

[0002] With the evolution of 6G wireless communication system network architecture, based on massive MIMO systems and combined with the characteristics of distributed antenna architecture, decellularized massive MIMO systems have been proposed. By using widely distributed access points, it solves the problems of inter-cell interference and handover in massive MIMO systems, further improving the system's spectrum efficiency and energy efficiency, and has become one of the potential key technologies for 6G.

[0003] In related technologies, due to the power consumption and cost limitations of a single access point in a decellularized massive MIMO system, the number of antennas configured at each access point is relatively small. Instead, a large number of distributed access points together form a massive MIMO structure. Therefore, the channel hardening phenomenon is not always fully satisfied. Using channel state statistics for downlink signal detection will result in a large deviation from the actual situation, which will seriously affect the downlink transmission performance of the system.

[0004] Therefore, it is evident that how to incorporate a downlink transmission method that can balance downlink data transmission performance and pilot overhead in a distributed antenna architecture system has become a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] This application provides a downlink data transmission method, apparatus, electronic device, and medium. This solves the problem of high downlink pilot transmission overhead in systems with distributed antenna architectures, which has been observed in related technologies.

[0006] According to one aspect of the embodiments of this application, a downlink data transmission method is provided, applied to a distributed multi-antenna system including user equipment, access point, and centralized processing unit, comprising:

[0007] After receiving the uplink pilot information sent by the user equipment at the access point, the channel state parameters of the user equipment are calculated based on the uplink pilot information.

[0008] The access point sends the channel state parameters to the centralized processing unit, and the centralized processing unit calculates the channel hardening ratio of the user equipment based on the channel state parameters.

[0009] Based on the relationship between the channel hardening ratio and the preset threshold, the centralized processing unit generates corresponding downlink pilot configuration information for the user equipment and sends it to the access point. The downlink pilot configuration information is used to indicate whether the user equipment needs to perform downlink channel estimation.

[0010] After the user equipment receives the downlink pilot configuration information sent by the access point, it transmits downlink data based on the downlink pilot configuration information.

[0011] Optionally, in another embodiment based on the method described above in this application, the step of calculating the channel state parameters of the user equipment based on the uplink pilot information includes:

[0012] Based on the uplink pilot information, the access point calculates a first channel state estimate of the user equipment, wherein the first channel state estimate is used to reflect the channel state between the user equipment and the access point at an instant.

[0013] Calculate the downlink precoding vector of the user equipment based on the first channel state estimate, and allocate the corresponding downlink transmit power to the user equipment;

[0014] The first channel state estimate, the downlink precoding vector, and the downlink transmit power are used as the channel state parameters of the user equipment.

[0015] Optionally, in another embodiment based on the method described above in this application, after using the first channel state estimate, the downlink precoding vector, and the downlink transmit power as channel state parameters of the user equipment, the method further includes:

[0016] The access point detects whether the current time point exceeds the timing threshold;

[0017] If the value exceeds the limit, based on the first channel state estimate, the channel state statistics of the user equipment are calculated and sent to the user equipment; and the first channel state estimate, the downlink precoding vector, and the downlink transmit power are sent to the centralized processing unit; wherein the channel state statistics are used to reflect the channel state between the user equipment and the access point at a future time.

[0018] If the value does not exceed the specified value, the first channel state estimate, the downlink precoding vector, and the downlink transmit power are sent to the centralized processing unit.

[0019] Optionally, in another embodiment based on the method described above in this application, the centralized processing unit generates corresponding downlink pilot configuration information for the user equipment based on the relationship between the channel hardening ratio and a preset threshold, and sends it to the access point, including:

[0020] If the centralized processing unit determines that the channel hardening ratio is greater than or equal to the preset threshold, it performs a first downlink pilot allocation on the user equipment, wherein the first downlink pilot allocation is used to instruct the user equipment to perform downlink channel estimation;

[0021] The first downlink pilot configuration information generated after the first downlink pilot allocation is sent to the access point;

[0022] or,

[0023] If the centralized processing unit determines that the channel hardening ratio is less than the preset threshold, it performs downlink pilot allocation on the user equipment and performs a second downlink pilot allocation, wherein the second downlink pilot allocation is used to instruct the user equipment not to perform downlink channel estimation;

[0024] The second downlink pilot configuration information generated after the second downlink pilot allocation is sent to the access point.

[0025] Optionally, in another embodiment based on the method described above, the centralized processing unit sends the first downlink pilot configuration information generated after the first downlink pilot allocation to the access point, including:

[0026] The centralized processing unit randomly assigns a corresponding orthogonal downlink pilot to the user equipment from a pre-set set of orthogonal downlink pilots;

[0027] The downlink pilot number corresponding to the orthogonal downlink pilot, the ID of the user equipment, and the first allocation indication corresponding to the first downlink pilot are used as the first downlink pilot configuration information;

[0028] The centralized processing unit sends the first downlink pilot configuration information to the access point.

[0029] Optionally, in another embodiment based on the method described above, the centralized processing unit sends the second downlink pilot configuration information generated after the second downlink pilot allocation to the access point, including:

[0030] The user equipment ID and the second allocation indication corresponding to the second downlink pilot are used as the second downlink pilot configuration information;

[0031] The centralized processing unit sends the second downlink pilot configuration information to the access point.

[0032] Optionally, in another embodiment based on the method described above in this application, the step of transmitting downlink data based on the downlink pilot configuration information after the user equipment receives the downlink pilot configuration information sent by the access point includes:

[0033] After receiving the downlink pilot configuration information, the user equipment obtains the downlink pilot configuration information carried in the downlink pilot configuration information;

[0034] If the downlink pilot configuration information is detected to include a downlink pilot number and a first allocation indication for instructing the user equipment to perform downlink channel estimation, instantaneous downlink channel estimation is performed based on the downlink pilot number to obtain a second channel state estimation value.

[0035] Downlink data transmission is performed using the second channel state estimate;

[0036] or,

[0037] If the downlink pilot configuration information is found to include a second allocation indication for indicating that the user equipment does not need to perform downlink channel estimation, downlink data transmission is performed based on the channel state statistics sent by the access point;

[0038] The channel state statistics are generated by the access point and are used to reflect the channel state between the user equipment and the access point at future times.

[0039] According to another aspect of the embodiments of this application, a downlink data transmission apparatus is provided for a distributed multi-antenna system including a user equipment, an access point, and a centralized processing unit, comprising:

[0040] The receiving module is configured to calculate the channel state parameters of the user equipment based on the uplink pilot information after the access point receives the uplink pilot information sent by the user equipment.

[0041] The calculation module is configured such that the access point sends the channel state parameters to the centralized processing unit, and the centralized processing unit calculates the channel hardening ratio of the user equipment based on the channel state parameters.

[0042] The comparison module is configured such that the centralized processing unit generates corresponding downlink pilot configuration information for the user equipment based on the relationship between the channel hardening ratio and a preset threshold, and sends it to the access point. The downlink pilot configuration information is used to indicate whether the user equipment needs to perform downlink channel estimation.

[0043] The transmission module is configured to transmit downlink data based on the downlink pilot configuration information sent by the access point after the user equipment receives the downlink pilot configuration information.

[0044] According to another aspect of the embodiments of this application, an electronic device is provided, comprising:

[0045] Memory, used to store executable instructions; and

[0046] A display for executing the executable instructions with the memory to perform the operation of any of the downlink data transmission methods described above.

[0047] According to another aspect of the embodiments of this application, a computer-readable storage medium is provided for storing computer-readable instructions, which, when executed, perform the operation of any of the downlink data transmission methods described above.

[0048] In this application, after the access point receives the uplink pilot information sent by the user equipment, it calculates the channel state parameters of the user equipment based on the uplink pilot information. The access point sends the channel state parameters to the centralized processing unit, which then calculates the channel hardening ratio of the user equipment based on the channel state parameters. The centralized processing unit generates corresponding downlink pilot configuration information for the user equipment based on the relationship between the channel hardening ratio and a preset threshold and sends it to the access point. The downlink pilot configuration information is used to indicate whether the user equipment needs to perform downlink channel estimation. After the user equipment receives the downlink pilot configuration information sent by the access point, it transmits downlink data based on the downlink pilot configuration information.

[0049] By applying the technical solution of this application, and addressing the issue of insufficient channel hardening conditions in distributed multi-antenna systems, this solution compares the channel hardening ratio between the user equipment and the access point with a preset threshold. Different downlink transmission methods are then applied to user equipment with different hardening ratios. This achieves a technical solution that adaptively balances transmission performance and transmission overhead based on the actual channel propagation conditions of the user equipment. Ultimately, it aims to reduce pilot overhead and improve the spectral efficiency of downlink transmission while ensuring the transmission performance of the distributed multi-antenna system.

[0050] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0051] The accompanying drawings, which form part of this specification, illustrate embodiments of this application and, together with the description, serve to explain the principles of this application.

[0052] This application can be more clearly understood with reference to the accompanying drawings and the following detailed description, wherein:

[0053] Figure 1 This is a schematic diagram of a downlink data transmission method proposed in this application;

[0054] Figure 2 This is a flowchart of a downlink data transmission method proposed in this application;

[0055] Figure 3 This is a system architecture diagram of a downlink data transmission method proposed in this application;

[0056] Figures 4a-4b This is a schematic diagram of downlink data transmission resources proposed in this application;

[0057] Figure 5 This is a schematic diagram of the electronic device proposed in this application;

[0058] Figure 6 This is a schematic diagram of the electronic device proposed in this application. Detailed Implementation

[0059] Various exemplary embodiments of this application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this application.

[0060] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0061] The following description of at least one exemplary embodiment is merely illustrative and is not intended to limit the scope of this application or its application or use.

[0062] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0063] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0064] Furthermore, the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0065] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0066] The following is combined with Figure 1 Figure 4 illustrates a method for transmitting downlink data according to an exemplary embodiment of this application. It should be noted that the following application scenarios are shown only to facilitate understanding of the spirit and principles of this application, and the embodiments of this application are not limited in any way. Rather, the embodiments of this application can be applied to any applicable scenario.

[0067] This application also proposes a method, apparatus, electronic device, and medium for transmitting downlink data.

[0068] Figure 1 A schematic flowchart illustrating a downlink data transmission method according to an embodiment of this application is shown. Figure 1 As shown, this method is applied to a distributed multi-antenna system including user equipment, access points, and a centralized processing unit, and includes:

[0069] S101 In this application, after the access point receives the uplink pilot information sent by the user equipment, the channel state parameters of the user equipment are calculated based on the uplink pilot information.

[0070] S102, the access point sends the channel status parameters to the centralized processing unit, and the centralized processing unit calculates the channel hardening ratio of the user equipment based on the channel status parameters.

[0071] S103, the centralized processing unit generates corresponding downlink pilot configuration information for the user equipment based on the relationship between the channel hardening ratio and the preset threshold, and sends it to the access point. The downlink pilot configuration information is used to indicate whether the user equipment needs to perform downlink channel estimation.

[0072] S104: After the user equipment receives the downlink pilot configuration information sent by the access point, it transmits downlink data based on the downlink pilot configuration information.

[0073] In related technologies, with the rapid development of the mobile internet, diverse business needs have placed new demands on the spectral efficiency, energy efficiency, and transmission reliability of wireless communication systems. Massive MIMO technology, as one of the key technologies of 5G wireless communication systems, can achieve more precise beamforming and interference suppression by installing hundreds or thousands of antennas at the base station. It extends wireless resources from the time and frequency dimensions to the spatial dimension, significantly reducing interference between users, effectively enhancing the reliability of system transmission, and multiplying the system's spectral efficiency and energy efficiency.

[0074] In one approach, research on massive MIMO systems typically assumes that the number of antennas on the base station side is much greater than the number of antennas on the user side. In this case, the system exhibits channel hardening characteristics, meaning that the instantaneous value of the channel tends to its statistical value, as shown below:

[0075] For the k-th user, we have

[0076] When LN→∞#(3-1).

[0077] Where L represents the number of base stations, and N represents the number of antennas per base station. For a centralized massive MIMO architecture, L = 1.

[0078] Understandably, when the channel hardening characteristics of a large-scale MIMO system are fully satisfied, the user equipment can achieve high downlink spectral efficiency by using only the channel state statistics under the current channel for downlink data signal detection.

[0079] However, with the evolution of 6G wireless communication system network architecture, based on massive MIMO systems and combined with the characteristics of distributed antenna architecture, decellularized massive MIMO systems have been proposed. By using widely distributed access points, it solves the problems of inter-cell interference and handover in massive MIMO systems, further improving the system's spectrum efficiency and energy efficiency, and has become one of the potential key technologies of 6G.

[0080] In related technologies, existing research typically assumes that decellularized massive MIMO systems inherit sufficient channel hardening characteristics from massive MIMO systems, omitting the downlink channel estimation process during downlink transmission, while the user equipment side uses channel state statistics for downlink data signal detection.

[0081] However, due to the power consumption and cost limitations of individual access points in decellularized massive MIMO systems, the number of antennas configured at each access point is relatively small. As a massive MIMO structure is formed by the antennas of a large number of distributed access points, the channel hardening phenomenon is not always fully satisfied. Using channel state statistics for downlink signal detection will result in a large deviation from the actual situation, which will seriously affect the downlink transmission performance of the system.

[0082] To address the aforementioned issues, some studies employ downlink transmission methods based on full-user downlink channel estimation. This involves performing pilot-based downlink channel estimation on all user sides, enabling users to obtain accurate instantaneous channel state information for downlink signal detection and thus improving system downlink transmission performance. Understandably, compared to traditional schemes relying solely on statistical channel information, the downlink pilot approach significantly improves system performance when the number of users is small.

[0083] In one approach, however, performance improvements become less noticeable when the number of users is large. This is because as the number of user devices increases, downlink pilot overhead and downlink pilot pollution also increase significantly, limiting further performance improvements in distributed multi-antenna systems.

[0084] To address the aforementioned issues, this application proposes a downlink data transmission method. The method involves comparing the channel hardening ratio between the user equipment and the access point with a preset threshold. User equipment with different hardening ratios is then assigned a differentiated downlink transmission method. This achieves a technical solution that adaptively balances transmission performance and transmission overhead based on the actual channel propagation conditions of the user equipment. Ultimately, this reduces pilot overhead and improves the spectral efficiency of downlink transmission while ensuring the transmission performance of the distributed multi-antenna system.

[0085] Furthermore, this application incorporates herein... Figure 2 The plan will be explained in detail:

[0086] Step 1: After receiving the uplink pilot information sent by the user equipment at the access point, the first channel state estimate of the user equipment is calculated based on the uplink pilot information.

[0087] The first channel state estimate is used to reflect the instantaneous channel state between the user equipment and the access point.

[0088] In one approach, such as Figure 3 The figure shows the distributed multi-antenna system proposed in this application. As can be seen from the figure, it is a distributed multi-antenna system for time division duplex (TDD). Multiple access points in the antenna system are distributed within a certain area and connected to a centralized processing unit via backhaul links, thereby serving multiple user equipment.

[0089] In one embodiment, the user equipment in this application can be one or more. The following example illustrates the use of multiple user equipment.

[0090] Step 2: The access point calculates the downlink precoding vector of the user equipment based on the first channel state estimate, allocates the corresponding downlink transmit power to the user equipment, and uses the first channel state estimate, the downlink precoding vector, and the downlink transmit power as the channel state parameters of the user equipment.

[0091] Each user equipment can send uplink pilot configuration to the access points in the distributed multi-antenna system and send uplink pilots to all access points.

[0092] Furthermore, the access point performs uplink channel estimation based on the uplink pilot information to obtain the uplink channel state estimate of the user equipment. Based on the estimate, it can calculate the downlink precoding vector corresponding to each user equipment and allocate the corresponding downlink transmit power to each user equipment.

[0093] Step 3: The access point checks whether the current time exceeds the timing threshold. If it does, proceed to step 4a. If it does not exceed the threshold, proceed to step 4b.

[0094] Step 4a: If the threshold is exceeded, calculate the channel state statistics of the user equipment based on the first channel state estimate, and send the channel state statistics to the user equipment. Also, send the first channel state estimate, downlink precoding vector, and downlink transmit power to the centralized processing unit, and then proceed to step 5.

[0095] Among them, the channel state statistics are used to reflect the channel state between the user equipment and the access point at future times.

[0096] The channel state statistics are calculated by averaging the uplink channel state estimates over a pre-set window period, and the results are updated when a pre-set timer reaches a timing threshold.

[0097] In one approach, if the access point confirms that the timing threshold has been exceeded at the current time, it can update the first channel state estimate to obtain a channel state statistic reflecting the channel state between the user equipment and the access point over a future period (i.e., inferring the channel state for the future period from the current channel state).

[0098] As an example, channel state statistics The calculation method can be as follows:

[0099]

[0100] in, Let be the uplink channel state estimate (i.e., the first channel state estimate) between the l-th access point and the k-th user equipment at time i, and T be the pre-set window length.

[0101] Step 4b: If the value does not exceed the limit, send the first channel state estimate, downlink precoding vector, and downlink transmit power to the centralized processing unit. Then proceed to step 5.

[0102] In one approach, if the access point confirms that the current time has not exceeded the timing threshold, it will send the uplink channel state estimates, downlink precoding vectors, and downlink transmit power of all user equipment to the centralized processing unit.

[0103] Step 5: The centralized processing unit calculates the channel hardening ratio of the user equipment based on the channel state parameters and checks the relationship between the channel hardening ratio and a preset threshold. If the channel hardening ratio is not less than the preset threshold, proceed to step 6a. If the channel hardening ratio is less than the preset threshold, proceed to step 6b.

[0104] In one approach, the channel hardening ratio is calculated as the variance of the ratio of the effective channel gain of the user equipment to its statistical value. The effective channel gain of the user equipment includes the downlink transmit power, downlink precoding gain, and channel gain between the user equipment and all access points.

[0105] In another approach, the downlink transmit power is calculated based on the uplink channel state estimate using power allocation algorithms such as the equal-division method, the water-filling method, or the maximum-minimum method. Similarly, the downlink precoding gain is calculated based on the uplink channel state estimate using downlink precoding algorithms such as the zero-forcing method or the minimum mean square error method.

[0106] In one approach, the channel gain can be approximated by the uplink channel state estimate.

[0107] The centralized processing unit calculates the channel hardening ratio based on the uplink channel state estimate, downlink precoding vector, and downlink transmit power of the user equipment.

[0108] As an example, with ξ k Let represent the channel hardening ratio of the k-th user equipment, and its calculation method is as follows:

[0109]

[0110] in, For the effective channel of the k-th user equipment, ρ lk The transmit power allocated to the k-th user equipment by the l-th access point. This is the estimated uplink channel state between the l-th access point and the k-th user equipment. This is the downlink precoding vector from the l-th access point to the k-th user equipment.

[0111] In another approach, the centralized processing unit can group individual user equipment according to a preset threshold σ that reflects the channel hardening threshold.

[0112] That is, in this embodiment of the application, user equipment with a channel hardening ratio greater than or equal to a preset threshold is divided into a first user equipment set; and user equipment with a channel hardening ratio less than the preset threshold is divided into another group to form a second user equipment set.

[0113] For example, if a user equipment k satisfies ξ k If ≥σ, then user equipment k is added to the first user equipment set. Understandably, all user equipment in the first set of user equipment needs to undergo a first downlink pilot allocation by the centralized processing unit (i.e., indicating that the user equipment subsequently needs downlink channel estimation). This leads to the process described in steps 6a-9a.

[0114] Conversely, if user equipment k satisfies ξ k If the value is less than σ, then user equipment k is placed in the second user equipment set. In the middle. Understandably, all user equipment in the second set of user equipment needs to have a second downlink pilot assigned to them by the centralized processing unit (i.e., indicating that the user equipment does not need to perform downlink channel estimation subsequently). That is, proceed to the process described in steps 6b-7b.

[0115] As an example, the preset threshold σ can be generated by the following formula:

[0116] σ=min{ξ k}+(max{ξ k}-min{ξ k})×θ#(4-3).

[0117] Where, min{ξ k} and max{ξ k} represent the set of channel hardening ratios for user equipment, respectively. k The minimum and maximum values ​​in} are defined by θ, which is a pre-set coefficient used to control the degree of deviation between the threshold and the minimum and maximum values.

[0118] Step 6a: The centralized processing unit randomly assigns a corresponding orthogonal downlink pilot to the user equipment from the pre-set set of orthogonal downlink pilots, and uses the downlink pilot sequence number corresponding to the orthogonal downlink pilot, the user equipment ID, and the first allocation indication corresponding to the first downlink pilot as the first downlink pilot configuration information; then the first downlink pilot configuration information is sent to the access point.

[0119] In one approach, for the centralized processing unit to process the first set of user equipment... In the process of allocating downlink pilots for user equipment in a distributed multi-antenna system, for example, the number of pre-set orthogonal downlink pilots is τ. pd Then, the τ pd A quadrature downlink pilot is assigned to the first set of user equipment. All user equipment.

[0120] In one approach, when the pre-set number of downlink orthogonal pilots is greater than or equal to the number of user equipments in the first user equipment set, different orthogonal downlink pilots are randomly assigned to each user equipment in the first user equipment set; when the number of downlink orthogonal pilots is less than the number of user equipments in the first user equipment set, a pilot allocation algorithm is needed to reuse pilots for multiple user equipments, such as a random pilot allocation algorithm or a greedy pilot allocation algorithm.

[0121] For example, when τ pd Greater than or equal to the first set of user equipment When the number of user equipment is sufficient (i.e., enough to allocate orthogonal downlink pilots), it can be considered the first set of user equipment. Each user equipment is randomly assigned a different orthogonal downlink pilot.

[0122] In another way, if τ pd Less than the first set of user equipment When the number of user equipment is insufficient (i.e., not enough to allocate orthogonal downlink pilots), pilot allocation algorithms are needed to reuse pilots for multiple user equipment, such as random pilot allocation algorithms and greedy pilot allocation algorithms.

[0123] Furthermore, the centralized processing unit sends the first downlink pilot configuration information corresponding to each user equipment to each access point. As an example, the format of this information is shown in the figure below, and it includes at least: User Equipment ID, downlink pilot allocation indication, and downlink pilot sequence number.

[0124] User Equipment ID First allocation instruction Downlink pilot number

[0125] Understandably, the first allocation instruction is the downlink pilot allocation instruction. The downlink pilot number is the downlink pilot number corresponding to the orthogonal downlink pilot allocated to this user equipment.

[0126] For example, if the first allocation indication is 1, it means that a downlink pilot has been allocated to the user equipment. If the first allocation indication is 0, it means that no downlink pilot has been allocated to the user equipment, and the subsequent downlink pilot sequence number is empty.

[0127] In other words, for the first set of user equipment For the user equipment in the first set, the downlink pilot allocation indication field is fixed at 1; for the second set of user equipment... In the user equipment, the downlink pilot allocation indication field is fixed to 0.

[0128] Furthermore, after receiving the first downlink pilot configuration information corresponding to the user equipment, the access point can send the corresponding downlink pilot configuration information to each user equipment. This will, understandably, include at least a downlink pilot allocation indication and a downlink pilot sequence number.

[0129] Step 7a: After receiving the first downlink pilot configuration information, the user equipment obtains the first downlink pilot configuration information carried in the first downlink pilot configuration information;

[0130] Step 8a: Detect that the first downlink pilot configuration information includes a downlink pilot number and a first allocation indication for instructing the user equipment to perform downlink channel estimation. Perform instantaneous downlink channel estimation based on the downlink pilot number to obtain the second channel state estimate.

[0131] Step 9a: Use the second channel state estimate to perform downlink data transmission.

[0132] In one approach, if the user equipment, after receiving a downlink signal, determines that instantaneous downlink channel estimation is required based on the downlink pilot allocation indication (i.e., the first allocation indication) in the first downlink pilot configuration information, then instantaneous downlink channel estimation is performed based on the pilot sequence corresponding to the downlink pilot number to obtain the downlink channel state estimate, and the downlink data signal detection is performed accordingly.

[0133] In one approach, the user equipment can employ, for example... Figure 4a The transmission method shown is used for downlink data transmission. The gray squares represent resource units used for downlink pilot transmission, and the white squares represent resource units used for downlink data transmission. In other words, the resource block used for downlink transmission includes both resource units for downlink pilot transmission and resource units for downlink data transmission.

[0134] Step 6b: The centralized processing unit uses the user equipment ID and the second allocation indication corresponding to the second downlink pilot as the second downlink pilot configuration information, and sends the second downlink pilot configuration information to the access point. Then proceed to step 7b.

[0135] Step 7b: The user equipment detects that the downlink pilot configuration information includes a second allocation indication that indicates that the user equipment does not need to perform downlink channel estimation, and performs downlink data transmission based on the channel state statistics sent by the access point.

[0136] Among them, the channel state statistics are generated by the access point and are used to reflect the channel state between the user equipment and the access point at future times.

[0137] In one approach, if the user equipment determines that instantaneous downlink channel estimation is not required based on the downlink pilot allocation indication (i.e., the second allocation indication) in the first downlink pilot configuration information after receiving the downlink signal, then the downlink data signal detection is directly performed using the channel state statistics calculated by the access point in step 3.

[0138] In one approach, the user equipment can employ, for example... Figure 4b The transmission method shown is used for downlink data transmission. The white squares represent resource units used for downlink data transmission. That is, the resource blocks used for downlink transmission contain only resource units for downlink data transmission.

[0139] In this application, after the access point receives the uplink pilot information sent by the user equipment, it calculates the channel state parameters of the user equipment based on the uplink pilot information. The access point sends the channel state parameters to the centralized processing unit, which then calculates the channel hardening ratio of the user equipment based on the channel state parameters. The centralized processing unit generates corresponding downlink pilot configuration information for the user equipment based on the relationship between the channel hardening ratio and a preset threshold and sends it to the access point. The downlink pilot configuration information is used to indicate whether the user equipment needs to perform downlink channel estimation. After the user equipment receives the downlink pilot configuration information sent by the access point, it transmits downlink data based on the downlink pilot configuration information.

[0140] By applying the technical solution of this application, and addressing the issue of insufficient channel hardening conditions in distributed multi-antenna systems, this solution compares the channel hardening ratio between the user equipment and the access point with a preset threshold. Different downlink transmission methods are then applied to user equipment with different hardening ratios. This achieves a technical solution that adaptively balances transmission performance and transmission overhead based on the actual channel propagation conditions of the user equipment. Ultimately, it aims to reduce pilot overhead and improve the spectral efficiency of downlink transmission while ensuring the transmission performance of the distributed multi-antenna system.

[0141] Optionally, in another embodiment based on the method described above in this application, the step of calculating the channel state parameters of the user equipment based on the uplink pilot information includes:

[0142] Based on the uplink pilot information, the access point calculates a first channel state estimate of the user equipment, wherein the first channel state estimate is used to reflect the channel state between the user equipment and the access point at an instant.

[0143] Calculate the downlink precoding vector of the user equipment based on the first channel state estimate, and allocate the corresponding downlink transmit power to the user equipment;

[0144] The first channel state estimate, the downlink precoding vector, and the downlink transmit power are used as the channel state parameters of the user equipment.

[0145] Optionally, in another embodiment based on the method described above in this application, after using the first channel state estimate, the downlink precoding vector, and the downlink transmit power as channel state parameters of the user equipment, the method further includes:

[0146] The access point detects whether the current time point exceeds the timing threshold;

[0147] If the value exceeds the limit, based on the first channel state estimate, the channel state statistics of the user equipment are calculated and sent to the user equipment; and the first channel state estimate, the downlink precoding vector, and the downlink transmit power are sent to the centralized processing unit; wherein the channel state statistics are used to reflect the channel state between the user equipment and the access point at a future time.

[0148] If the value does not exceed the specified value, the first channel state estimate, the downlink precoding vector, and the downlink transmit power are sent to the centralized processing unit.

[0149] Optionally, in another embodiment based on the method described above in this application, the centralized processing unit generates corresponding downlink pilot configuration information for the user equipment based on the relationship between the channel hardening ratio and a preset threshold, and sends it to the access point, including:

[0150] If the centralized processing unit determines that the channel hardening ratio is greater than or equal to the preset threshold, it performs a first downlink pilot allocation on the user equipment, wherein the first downlink pilot allocation is used to instruct the user equipment to perform downlink channel estimation;

[0151] The first downlink pilot configuration information generated after the first downlink pilot allocation is sent to the access point;

[0152] or,

[0153] If the centralized processing unit determines that the channel hardening ratio is less than the preset threshold, it performs downlink pilot allocation on the user equipment and performs a second downlink pilot allocation, wherein the second downlink pilot allocation is used to instruct the user equipment not to perform downlink channel estimation;

[0154] The second downlink pilot configuration information generated after the second downlink pilot allocation is sent to the access point.

[0155] Optionally, in another embodiment based on the method described above, the centralized processing unit sends the first downlink pilot configuration information generated after the first downlink pilot allocation to the access point, including:

[0156] The centralized processing unit randomly assigns a corresponding orthogonal downlink pilot to the user equipment from a pre-set set of orthogonal downlink pilots;

[0157] The downlink pilot number corresponding to the orthogonal downlink pilot, the ID of the user equipment, and the first allocation indication corresponding to the first downlink pilot are used as the first downlink pilot configuration information;

[0158] The centralized processing unit sends the first downlink pilot configuration information to the access point.

[0159] Optionally, in another embodiment based on the method described above, the centralized processing unit sends the second downlink pilot configuration information generated after the second downlink pilot allocation to the access point, including:

[0160] The user equipment ID and the second allocation indication corresponding to the second downlink pilot are used as the second downlink pilot configuration information;

[0161] The centralized processing unit sends the second downlink pilot configuration information to the access point.

[0162] Optionally, in another embodiment based on the method described above in this application, the step of transmitting downlink data based on the downlink pilot configuration information after the user equipment receives the downlink pilot configuration information sent by the access point includes:

[0163] After receiving the downlink pilot configuration information, the user equipment obtains the downlink pilot configuration information carried in the downlink pilot configuration information;

[0164] If the downlink pilot configuration information is detected to include a downlink pilot number and a first allocation indication for instructing the user equipment to perform downlink channel estimation, instantaneous downlink channel estimation is performed based on the downlink pilot number to obtain a second channel state estimation value.

[0165] Downlink data transmission is performed using the second channel state estimate;

[0166] or,

[0167] If the downlink pilot configuration information is found to include a second allocation indication for indicating that the user equipment does not need to perform downlink channel estimation, downlink data transmission is performed based on the channel state statistics sent by the access point;

[0168] The channel state statistics are generated by the access point and are used to reflect the channel state between the user equipment and the access point at future times.

[0169] In one way, Figure 5 This is a flowchart illustrating the signaling interaction between the user equipment side and the base station side (including the access point and the centralized processing unit) in the downlink data transmission method proposed in this application.

[0170] In this embodiment of the application, during the downlink transmission process of the wireless communication system, the channel state statistics and channel hardening ratio are calculated based on the uplink channel state estimation value between the distributed multi-antenna and the user equipment. The user equipment is then grouped according to a preset threshold, and downlink pilots are allocated to specific user equipment groups. By using downlink pilot allocation information and downlink pilot configuration information for multiple user equipment groups, differentiated downlink transmission formats are adopted for different groups of user equipment, and the corresponding downlink data signal detection is completed at the receiving end.

[0171] Furthermore, the preset threshold can be calculated as a value within a closed interval between the minimum and maximum channel hardening ratios of all user equipment. Understandably, the degree of deviation from the maximum or minimum channel hardening ratio of user equipment can be determined by a preset coefficient, and this coefficient can be variable in practical applications.

[0172] By applying the technical solution of this application, and addressing the issue of insufficient channel hardening conditions in distributed multi-antenna systems, this solution compares the channel hardening ratio between the user equipment and the access point with a preset threshold. Different downlink transmission methods are then applied to user equipment with different hardening ratios. This achieves a technical solution that adaptively balances transmission performance and transmission overhead based on the actual channel propagation conditions of the user equipment. Ultimately, it aims to reduce pilot overhead and improve the spectral efficiency of downlink transmission while ensuring the transmission performance of the distributed multi-antenna system.

[0173] Optionally, in another embodiment of this application, such as Figure 5 As shown, this application also provides a downlink data transmission apparatus. It includes:

[0174] The receiving module 201 is configured to calculate the channel state parameters of the user equipment based on the uplink pilot information after the access point receives the uplink pilot information sent by the user equipment.

[0175] The calculation module 202 is configured such that the access point sends the channel state parameters to the centralized processing unit, and the centralized processing unit calculates the channel hardening ratio of the user equipment based on the channel state parameters.

[0176] The comparison module 203 is configured such that the centralized processing unit generates corresponding downlink pilot configuration information for the user equipment based on the relationship between the channel hardening ratio and the preset threshold and sends it to the access point. The downlink pilot configuration information is used to indicate whether the user equipment needs to perform downlink channel estimation.

[0177] The transmission module 204 is configured to transmit downlink data based on the downlink pilot configuration information after the user equipment receives the downlink pilot configuration information sent by the access point.

[0178] By applying the technical solution of this application, and addressing the issue of insufficient channel hardening conditions in distributed multi-antenna systems, this solution compares the channel hardening ratio between the user equipment and the access point with a preset threshold. Different downlink transmission methods are then applied to user equipment with different hardening ratios. This achieves a technical solution that adaptively balances transmission performance and transmission overhead based on the actual channel propagation conditions of the user equipment. Ultimately, it aims to reduce pilot overhead and improve the spectral efficiency of downlink transmission while ensuring the transmission performance of the distributed multi-antenna system.

[0179] In another embodiment of this application, the computing module 202 is configured as follows:

[0180] Based on the uplink pilot information, the access point calculates a first channel state estimate of the user equipment, wherein the first channel state estimate is used to reflect the channel state between the user equipment and the access point at an instant.

[0181] Calculate the downlink precoding vector of the user equipment based on the first channel state estimate, and allocate the corresponding downlink transmit power to the user equipment;

[0182] The first channel state estimate, the downlink precoding vector, and the downlink transmit power are used as the channel state parameters of the user equipment.

[0183] In another embodiment of this application, the computing module 202 is configured as follows:

[0184] The access point detects whether the current time point exceeds the timing threshold;

[0185] If the value exceeds the limit, based on the first channel state estimate, the channel state statistics of the user equipment are calculated and sent to the user equipment; and the first channel state estimate, the downlink precoding vector, and the downlink transmit power are sent to the centralized processing unit; wherein the channel state statistics are used to reflect the channel state between the user equipment and the access point at a future time.

[0186] If the value does not exceed the specified value, the first channel state estimate, the downlink precoding vector, and the downlink transmit power are sent to the centralized processing unit.

[0187] In another embodiment of this application, the computing module 202 is configured as follows:

[0188] If the centralized processing unit determines that the channel hardening ratio is greater than or equal to the preset threshold, it performs a first downlink pilot allocation on the user equipment, wherein the first downlink pilot allocation is used to instruct the user equipment to perform downlink channel estimation;

[0189] The first downlink pilot configuration information generated after the first downlink pilot allocation is sent to the access point;

[0190] or,

[0191] If the centralized processing unit determines that the channel hardening ratio is less than the preset threshold, it performs downlink pilot allocation on the user equipment and performs a second downlink pilot allocation, wherein the second downlink pilot allocation is used to instruct the user equipment not to perform downlink channel estimation;

[0192] The second downlink pilot configuration information generated after the second downlink pilot allocation is sent to the access point.

[0193] In another embodiment of this application, the computing module 202 is configured as follows:

[0194] The centralized processing unit randomly assigns a corresponding orthogonal downlink pilot to the user equipment from a pre-set set of orthogonal downlink pilots;

[0195] The downlink pilot number corresponding to the orthogonal downlink pilot, the ID of the user equipment, and the first allocation indication corresponding to the first downlink pilot are used as the first downlink pilot configuration information;

[0196] The centralized processing unit sends the first downlink pilot configuration information to the access point.

[0197] In another embodiment of this application, the computing module 202 is configured as follows:

[0198] The centralized processing unit uses the user equipment ID and the second allocation indication corresponding to the second downlink pilot as the second downlink pilot configuration information.

[0199] The centralized processing unit sends the second downlink pilot configuration information to the access point.

[0200] In another embodiment of this application, the computing module 202 is configured as follows:

[0201] After receiving the downlink pilot configuration information, the user equipment obtains the downlink pilot configuration information carried in the downlink pilot configuration information;

[0202] If the downlink pilot configuration information is detected to include a downlink pilot number and a first allocation indication for instructing the user equipment to perform downlink channel estimation, instantaneous downlink channel estimation is performed based on the downlink pilot number to obtain a second channel state estimation value.

[0203] Downlink data transmission is performed using the second channel state estimate;

[0204] or,

[0205] If the downlink pilot configuration information is found to include a second allocation indication for indicating that the user equipment does not need to perform downlink channel estimation, downlink data transmission is performed based on the channel state statistics sent by the access point;

[0206] The channel state statistics are generated by the access point and are used to reflect the channel state between the user equipment and the access point at future times.

[0207] Figure 6 This is a logical structure block diagram of an electronic device according to an exemplary embodiment. For example, electronic device 300 may be an electronic device.

[0208] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions, such as a memory including instructions, is also provided. These instructions can be executed by an electronic device processor to complete the downlink data transmission method described above. The method includes: after the access point receives uplink pilot information sent by the user equipment, calculating channel state parameters of the user equipment based on the uplink pilot information; the access point sends the channel state parameters to a centralized processing unit, and the centralized processing unit calculates the channel hardening ratio of the user equipment based on the channel state parameters; the centralized processing unit generates corresponding downlink pilot configuration information for the user equipment based on the relationship between the channel hardening ratio and a preset threshold, and sends this information to the access point, wherein the downlink pilot configuration information is used to indicate whether the user equipment needs to perform downlink channel estimation; and after the user equipment receives the downlink pilot configuration information sent by the access point, transmitting downlink data based on the downlink pilot configuration information.

[0209] Optionally, the above instructions can also be executed by the processor of the electronic device to complete other steps involved in the exemplary embodiments described above. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0210] In an exemplary embodiment, an application / computer program product is also provided, including one or more instructions that can be executed by a processor of an electronic device to complete the aforementioned downlink data transmission method. The method includes: after the access point receives uplink pilot information sent by the user equipment, calculating channel state parameters of the user equipment based on the uplink pilot information; the access point sends the channel state parameters to the centralized processing unit, and the centralized processing unit calculates the channel hardening ratio of the user equipment based on the channel state parameters; the centralized processing unit generates corresponding downlink pilot configuration information for the user equipment based on the relationship between the channel hardening ratio and a preset threshold and sends it to the access point, the downlink pilot configuration information indicating whether the user equipment needs to perform downlink channel estimation; and after the user equipment receives the downlink pilot configuration information sent by the access point, transmitting downlink data based on the downlink pilot configuration information.

[0211] Alternatively, the above instructions may also be executed by the processor of the electronic device to complete other steps involved in the above exemplary embodiments.

[0212] Figure 6 This is an example diagram of an electronic device 300. Those skilled in the art will understand that it is illustrative. Figure 6 This is merely an example of electronic device 300 and does not constitute a limitation on electronic device 300. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device 300 may also include input / output devices, network access devices, buses, etc.

[0213] The processor 302 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor, or processor 302 can be any conventional processor. Processor 302 is the control center of electronic device 300, connecting all parts of electronic device 300 via various interfaces and lines.

[0214] The memory 301 can be used to store computer-readable instructions 303. The processor 302 implements various functions of the electronic device 300 by running or executing the computer-readable instructions or modules stored in the memory 301 and calling the data stored in the memory 301. The memory 301 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, application programs required for at least one function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the electronic device 300, etc. In addition, the memory 301 may include a hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, read-only memory (ROM), random access memory (RAM), or other non-volatile / volatile storage devices.

[0215] If the modules integrated in the electronic device 300 are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by instructing related hardware through computer-readable instructions. The computer-readable instructions can be stored in a computer-readable storage medium, and when executed by a processor, the computer-readable instructions can implement the steps of the various method embodiments described above.

[0216] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0217] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for transmitting downlink data, characterized in that, Applications include distributed multi-antenna systems comprising user equipment, access points, and centralized processing units, including: After receiving the uplink pilot information sent by the user equipment at the access point, the channel state parameters of the user equipment are calculated based on the uplink pilot information. The access point sends the channel state parameters to the centralized processing unit, and the centralized processing unit calculates the channel hardening ratio of the user equipment based on the channel state parameters. Based on the relationship between the channel hardening ratio and the preset threshold, the centralized processing unit generates corresponding downlink pilot configuration information for the user equipment and sends it to the access point. The downlink pilot configuration information is used to indicate whether the user equipment needs to perform downlink channel estimation. After the user equipment receives the downlink pilot configuration information sent by the access point, it transmits downlink data based on the downlink pilot configuration information.

2. The method as described in claim 1, characterized in that, The calculation of the channel state parameters of the user equipment based on the uplink pilot information includes: Based on the uplink pilot information, the access point calculates a first channel state estimate of the user equipment, wherein the first channel state estimate is used to reflect the channel state between the user equipment and the access point at an instant. Calculate the downlink precoding vector of the user equipment based on the first channel state estimate, and allocate the corresponding downlink transmit power to the user equipment; The first channel state estimate, the downlink precoding vector, and the downlink transmit power are used as the channel state parameters of the user equipment.

3. The method as described in claim 2, characterized in that, After using the first channel state estimate, the downlink precoding vector, and the downlink transmit power as channel state parameters of the user equipment, the method further includes: The access point detects whether the current time point exceeds the timing threshold; If the value exceeds the limit, based on the first channel state estimate, the channel state statistics of the user equipment are calculated and sent to the user equipment; and the first channel state estimate, the downlink precoding vector, and the downlink transmit power are sent to the centralized processing unit; wherein the channel state statistics are used to reflect the channel state between the user equipment and the access point at a future time. If the value does not exceed the specified value, the first channel state estimate, the downlink precoding vector, and the downlink transmit power are sent to the centralized processing unit.

4. The method as described in claim 1, characterized in that, The centralized processing unit generates corresponding downlink pilot configuration information for the user equipment based on the relationship between the channel hardening ratio and a preset threshold, and sends it to the access point, including: If the centralized processing unit determines that the channel hardening ratio is greater than or equal to the preset threshold, it performs a first downlink pilot allocation on the user equipment, wherein the first downlink pilot allocation is used to instruct the user equipment to perform downlink channel estimation; The first downlink pilot configuration information generated after the first downlink pilot allocation is sent to the access point; or, If the centralized processing unit determines that the channel hardening ratio is less than the preset threshold, it performs downlink pilot allocation on the user equipment and performs a second downlink pilot allocation, wherein the second downlink pilot allocation is used to instruct the user equipment not to perform downlink channel estimation; The second downlink pilot configuration information generated after the second downlink pilot allocation is sent to the access point.

5. The method as described in claim 4, characterized in that, The centralized processing unit sends the first downlink pilot configuration information generated after the first downlink pilot allocation to the access point, including: The centralized processing unit randomly assigns a corresponding orthogonal downlink pilot to the user equipment from a pre-set set of orthogonal downlink pilots; The downlink pilot number corresponding to the orthogonal downlink pilot, the ID of the user equipment, and the first allocation indication corresponding to the first downlink pilot are used as the first downlink pilot configuration information; The centralized processing unit sends the first downlink pilot configuration information to the access point.

6. The method as described in claim 4, characterized in that, The centralized processing unit sends the second downlink pilot configuration information generated after the second downlink pilot allocation to the access point, including: The centralized processing unit uses the user equipment ID and the second allocation indication corresponding to the second downlink pilot as the second downlink pilot configuration information. The centralized processing unit sends the second downlink pilot configuration information to the access point.

7. The method as described in claim 1, characterized in that, The step of transmitting downlink data based on the downlink pilot configuration information after the user equipment receives the downlink pilot configuration information sent by the access point includes: After receiving the downlink pilot configuration information, the user equipment obtains the downlink pilot configuration information carried in the downlink pilot configuration information; If the downlink pilot configuration information is detected to include a downlink pilot number and a first allocation indication for instructing the user equipment to perform downlink channel estimation, instantaneous downlink channel estimation is performed based on the downlink pilot number to obtain a second channel state estimation value. Downlink data transmission is performed using the second channel state estimate; or, If the downlink pilot configuration information is found to include a second allocation indication for indicating that the user equipment does not need to perform downlink channel estimation, downlink data transmission is performed based on the channel state statistics sent by the access point; The channel state statistics are generated by the access point and are used to reflect the channel state between the user equipment and the access point at future times.

8. A downlink data transmission device, characterized in that, Applications include distributed multi-antenna systems comprising user equipment, access points, and centralized processing units, including: The receiving module is configured to calculate the channel state parameters of the user equipment based on the uplink pilot information after the access point receives the uplink pilot information sent by the user equipment. The calculation module is configured such that the access point sends the channel state parameters to the centralized processing unit, and the centralized processing unit calculates the channel hardening ratio of the user equipment based on the channel state parameters. The comparison module is configured such that the centralized processing unit generates corresponding downlink pilot configuration information for the user equipment based on the relationship between the channel hardening ratio and a preset threshold, and sends it to the access point. The downlink pilot configuration information is used to indicate whether the user equipment needs to perform downlink channel estimation. The transmission module is configured to transmit downlink data based on the downlink pilot configuration information sent by the access point after the user equipment receives the downlink pilot configuration information.

9. An electronic device, characterized in that, include: Memory, used to store executable instructions; as well as, A processor, configured to execute the executable instructions with the memory to perform the operation of the downlink data transmission method of any one of claims 1-7.

10. A computer-readable storage medium for storing computer-readable instructions, characterized in that, When the instruction is executed, it performs the operation of the downlink data transmission method according to any one of claims 1-7.

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