Beamforming for interference suppression

Abstract

Systems, methods, apparatuses, and computer program products for interference reduction. A method may include calculating at least one downlink beamforming coefficient vector and estimating at least one channel coefficient. Interference may be calculated and a configuration may be selected based on a determination of interference power. The transformed beamforming coefficient vector may be calculated by at least one of: minimizing the maximum interference power on one or more uplink antenna elements, minimizing the average interference power on one or more uplink antenna elements, or minimizing the interference power based on uplink beamforming.

Description

Technical Field

[0001] Some example embodiments may generally relate to systems and methods for reducing interference in a mobile or wireless telecommunications system. Background Art

[0002] Examples of mobile or wireless telecommunications systems may include Third Generation Partnership Project (3GPP) Long Term Evolution (LTE), Fifth Generation (5G) Radio Access Technology (RAT), New Radio (NR) access technology, Sixth Generation (6G), and / or other communication systems. In some cases, example mobile or wireless telecommunications systems may include Radio Frequency (RF) 5G RAT, Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), LTE Evolved UTRAN (E-UTRAN), Advanced LTE (LTE-A), LTE-A Pro, NR access technology, and / or the MulteFire Alliance. A 5G wireless system refers to a Next Generation (NG) radio system and network architecture.

[0003] 5G systems are generally built on 5G NR, but 5G (or NG) networks can also be built on E-UTRA radio. It is expected that NR can support service categories such as enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine type communication (mMTC). It is expected that NR will provide extreme broadband, ultra-robust, low-latency connectivity, and massive networking to support the Internet of Things (IoT). The Next Generation Radio Access Network (NG-RAN) represents the radio access network (RAN) for 5G, which can provide NR, LTE, and LTE-A with radio access.

[0004] Note that a node in 5G that provides radio access functionality to a user equipment (e.g., similar to Node B in UTRAN or evolved Node B (eNB) in LTE) can be referred to as a Next Generation Node B (gNB) when built on NR radio and as a Next Generation eNB (NG-eNB) when built on E-UTRA radio. Summary of the Invention

[0005] According to some example embodiments, a method may include determining an interference channel matrix of an antenna array having a plurality of uplink antenna elements and a plurality of downlink antenna elements. The method may further include determining an untransformed beamforming coefficient vector. The method may further include using the untransformed beamforming coefficient vector and the interference channel matrix to determine a transformed beamforming coefficient vector. The method may further include using the transformed beamforming coefficient vector to determine interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements, and determining a power of the interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements. The method may further include determining a maximum interference of the antenna array based on the determined interference power. The method may further include operating the antenna array based on the transformed beamforming coefficient vector in response to the maximum interference being less than or equal to a maximum interference of a predefined target.

[0006] According to certain example embodiments, an apparatus may include means for determining an interference channel matrix of an antenna array having a plurality of uplink antenna elements and a plurality of downlink antenna elements. The apparatus may further include means for determining an untransformed beamforming coefficient vector. The apparatus may further include means for using the untransformed beamforming coefficient vector and the interference channel matrix to determine a transformed beamforming coefficient vector. The apparatus may further include means for using the transformed beamforming coefficient vector to determine interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements, and determining a power of the interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements. The apparatus may further include means for determining a maximum interference of the antenna array based on the determined interference power. The apparatus may further include means for operating the antenna array based on the transformed beamforming coefficient vector in response to the maximum interference being less than or equal to a maximum interference of a predefined target.

[0007] According to various example embodiments, a non-transitory computer-readable medium may include program instructions that, when executed by a device, cause the device to perform at least one method. The method may include determining an interference channel matrix of an antenna array having a plurality of uplink antenna elements and a plurality of downlink antenna elements. The method may further include determining an untransformed beamforming coefficient vector. The method may further include using the untransformed beamforming coefficient vector and the interference channel matrix to determine a transformed beamforming coefficient vector. The method may further include using the transformed beamforming coefficient vector to determine interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements, and determining a power of the interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements. The method may further include determining a maximum interference of the antenna array based on the determined interference power. The method may further include operating the antenna array based on the transformed beamforming coefficient vector in response to the maximum interference being less than or equal to a maximum interference of a predefined target.

[0008] According to some example embodiments, a computer program product may execute a method. The method may include determining an interference channel matrix of an antenna array having a plurality of uplink antenna elements and a plurality of downlink antenna elements. The method may further include determining an untransformed beamforming coefficient vector. The method may further include using the untransformed beamforming coefficient vector and the interference channel matrix to determine a transformed beamforming coefficient vector. The method may further include using the transformed beamforming coefficient vector to determine interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements, and determining a power of the interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements. The method may further include determining a maximum interference of the antenna array based on the determined interference power. The method may further include operating the antenna array based on the transformed beamforming coefficient vector in response to the maximum interference being less than or equal to a maximum interference of a predefined target.

[0009] According to certain example embodiments, a device may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the device to at least determine an interference channel matrix of an antenna array having a plurality of uplink antenna elements and a plurality of downlink antenna elements. The at least one memory and the instructions, when executed by the at least one processor, may further cause the device to at least determine an untransformed beamforming coefficient vector. The at least one memory and the instructions, when executed by the at least one processor, may further cause the device to at least use the untransformed beamforming coefficient vector and the interference channel matrix to determine a transformed beamforming coefficient vector. The at least one memory and the instructions, when executed by the at least one processor, may further cause the device to at least use the transformed beamforming coefficient vector to determine interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements, and determining a power of the interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements. The at least one memory and the instructions, when executed by the at least one processor, may further cause the device to at least determine a maximum interference of the antenna array based on the determined interference power. The at least one memory and the instructions, when executed by the at least one processor, may further cause the device to at least operate the antenna array based on the transformed beamforming coefficient vector in response to the maximum interference being less than or equal to a maximum interference of a predefined target.

[0010] According to various example embodiments, a device may include first determination circuitry configured to perform determining an interference channel matrix of an antenna array having a plurality of uplink antenna elements and a plurality of downlink antenna elements. The device may further include second determination circuitry configured to perform determining an untransformed beamforming coefficient vector. The device may further include third determination circuitry configured to perform determining a transformed beamforming coefficient vector using the untransformed beamforming coefficient vector and the interference channel matrix. The device may further include fourth determination circuitry configured to perform the following operations: determining interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements using the transformed beamforming coefficient vector, and determining power of the interference of the plurality of uplink antenna elements and the plurality of downlink antenna elements. The device may further include fifth determination circuitry configured to perform determining a maximum interference of the antenna array based on the determined interference power. The device may further include operation circuitry configured to perform operating the antenna array based on the transformed beamforming coefficient vector in response to the maximum interference being less than or equal to a predefined target maximum interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] To correctly understand the example embodiments, reference should be made to the drawings, in which:

[0012] Figure 1 An example of a sub-band full-duplex time-frequency configuration is illustrated;

[0013] Figure 2 An example of an antenna array configuration in a UL time slot, a DL time slot, and a flexible time slot according to certain example embodiments is illustrated;

[0014] Figure 3 An example enumeration of antenna elements according to some example embodiments is illustrated;

[0015] Figure 4 An example of an antenna array in two configurations in a UL time slot, a DL time slot, and a flexible time slot according to various example embodiments is illustrated;

[0016] Figure 5 An example of a flowchart of a method according to various example embodiments is illustrated;

[0017] Figure 6 An example of an antenna array configuration in a UL time slot, a DL time slot, and a flexible time slot having two configurations according to certain example embodiments is illustrated;

[0018] Figure 7 An example implementation having two antenna panels according to some example embodiments is illustrated;

[0019] Figure 8Illustrates an example of a variable-sized subset according to various example embodiments;

[0020] Figure 9 Illustrates another example enumeration of antenna elements according to some example embodiments;

[0021] Figure 10 Illustrates an example block diagram according to some example embodiments;

[0022] Figure 11 Illustrates another example block diagram according to some example embodiments;

[0023] Figure 12 Illustrates an example of a hardware solution according to various example embodiments;

[0024] Figure 13 Illustrates examples of various network devices according to certain example embodiments; and

[0025] Figure 14 Illustrates an example of a 5G network and system architecture according to some example embodiments. Detailed Description

[0026] It is readily understood that, as generally depicted and described in the figures herein, the components of certain example embodiments may be arranged and designed in a variety of different configurations. Accordingly, the following detailed description of some example embodiments of systems, methods, apparatuses, and computer program products for interference reduction is not intended to limit the scope of certain example embodiments, but rather represents the selected example embodiments.

[0027] Recognizing that there are several types of interference (e.g., gNB interference) for sub-band full-duplex (SBFD) deployments for different uplink (UL) / downlink (DL) sub-band configurations, 3GPP continues to develop sub-band non-overlapping full-duplex (SBFD). Merely as some examples, relevant types of interference include, but are not limited to, self-interference at the base station, self-interference at the user equipment, base station-to-base station cross-link interference, sector-to-sector cross-link interference, user equipment-to-user equipment inter-cell cross-link interference, user equipment-to-user equipment intra-cell cross-link interference, user equipment-to-base station inter-cell cross-link interference, and base station-to-user inter-cell cross-link interference.

[0028] NR / 5G includes two types of duplexing schemes: Time Division Duplexing (TDD) and Frequency Division Duplexing (FDD). TDD can use the same frequency channel for DL and UL transmissions, and DL and UL can be separated in time. Similarly, FDD can use two frequency channels: one frequency channel for DL and another frequency channel for UL transmission. DL and UL can also overlap in time. FDD can also be Half Duplex FDD by using two frequency channels, but there is no DL and UL overlap in time, thus avoiding the use of expensive duplex filters.

[0029] SBFD is a relatively new duplexing scheme and is based on TDD. Specifically, in TDD, only slot (or partial slot) transmissions may be allowed in either the DL or UL direction. In contrast, in SBFD, slot transmissions are allowed in both directions. Similar to TDD, SBFD uses a single frequency channel. UL and DL transmissions can occur on two or more temporarily allocated frequency sub-channels.

[0030] Although SBFD offers several advantages, it also poses challenges of interference. To enable UL reception, in DL, the base station receiver should be protected (i.e., isolated) from its own transmissions (e.g., by more than 80 dB). In FDD, UL and DL transmissions can occur on different frequency channels, and the receiver can be protected from its own transmissions by a duplex filter. In SBFD, UL and DL transmissions can occur on the same frequency channel (but on different frequency sub-channels). These sub-channels can be temporarily allocated based on demand, and in contrast to FDD, it is impractical to use a duplex filter to protect one sub-channel from interference by another sub-channel. Another complication in SBFD implementation is that in FDD, the UL and DL frequency channels are separated by dozens of MHz, while in SBFD, the gap can be several Resource Blocks (RBs) (i.e., hundreds of kHz). Since duplex filters in SBFD are impractical, isolation can be achieved in different ways.

[0031] Certain example embodiments described herein can have various benefits and / or advantages that overcome the disadvantages described herein. For example, certain example embodiments can provide relatively simple and easy-to-implement interference reduction and can be combined with other interference mitigation methods. Thus, certain example embodiments discussed below are directed to improvements in computer-related technologies.

[0032] In some example embodiments, the antenna array can have two or more configurations in a flexible time slot. The configurations can differ based on which antenna elements of the base station are allocated for UL (e.g., used by the base station for receiving (RX)) and which are allocated for DL (e.g., used by the base station for transmitting (TX)). The base station can select the corresponding configuration, which can reduce interference. The precoder vector (hereinafter referred to as the "beamforming coefficient vector") and the interference channel matrix can be used to calculate the interference. Since the interference may depend on the beamforming coefficient vector, the selection can be performed each time the beamforming coefficient vector changes.

[0033] To obtain channel state information (CSI) for antenna configuration using the CSI reporting request mechanism in a flexible time slot, the base station can report to the user equipment (such as Figure 13 the user equipment (UE) 1320 shown in) which antenna configuration is selected for each time interval (e.g., X), and the base station can then request a CSI report for the selected antenna configuration. The UE can calculate the CSI report based on the time interval in which the antenna configuration is consistent with the requested CSI and send the CSI report to the base station.

[0034] To obtain CSI information for antenna configuration using sounding reference signals (SRS) in a flexible time slot, the base station can report to the UE which antenna configuration is selected for each time interval (flexible time slot), and request SRS for the selected antenna configuration. Then the UE can emit SRS and the requested antenna configuration over the time interval.

[0035] Figure 1 Illustrates an example of the time-frequency configuration of SBFD. Although Figure 1 the time slot is illustrated as a time unit, it can be associated with a time slot, symbol, etc. In DL and UL, time slot transmissions can occur in one direction. In X, time slot transmissions can occur in DL and UL. Figure 1 Illustrates an example configuration of a flexible time slot in the frequency domain, where the UL subband is allocated between two DL subbands.

[0036] Figure 2 Illustrates an example of a dual-polarized rectangular antenna array. In the UL time slot, the entire array can be configured for receiving, while in the DL time slot, the entire array can be configured for transmitting. In a flexible time slot, the antenna elements can be split into two subsets: one subset for DL and one subset for UL.

[0037] Various embodiments for configuring a flexible time slot are described herein. Figure 3 Illustrates an example of the enumeration of antenna elements. If as Figure 4For the antenna elements shown in the layout, in the first configuration, antenna elements 0 - 15 can be configured for UL, and antenna elements 16 - 32 can be configured for DL. In the second configuration, antenna elements 0 - 15 can be configured for DL, and antenna elements 16 - 32 can be configured for UL.

[0038] The base station can select one of the first configuration or the second configuration to minimize interference. Assuming a tapped channel and a uniform DL signal, the interference from one or more DL antenna elements to the nth UL antenna element can be defined as where h(m, n) can be the channel coefficient between the mth DL element and the nth UL element. This channel can be a direct link between the antenna elements and / or reflections from clutter. can be the mth coefficient of the DL beamforming coefficient vector.

[0039] In various example embodiments, selecting between the first configuration or the second configuration can include various considerations, such as but not limited to, minimizing the maximum interference power on one or more UL antenna elements according to Equation (1), such that

[0040]

[0041] minimizing the average interference power on one or more UL antenna elements according to Equation (2), such that

[0042]

[0043] and / or minimizing the interference power based on UL beamforming according to Equation (3), such that

[0044]

[0045] where can be the nth coefficient of the UL beamforming coefficient vector, and N can be the number of UL antenna elements. Accordingly, in some examples, minimizing the maximum interference power can be based on the maximum interference power from one or more downlink antenna elements to a given uplink antenna element among multiple uplink antenna elements, minimizing the average interference power from one or more downlink antenna elements to a given uplink antenna element among multiple uplink antenna elements can include determining the average interference power, and / or minimizing the interference power can include applying an uplink beamforming vector.

[0046] In one example, as described herein, minimizing the maximum interference power on one or more UL antenna elements can reduce the dynamic range of the signal at an individual antenna element. The interference can be very large compared to the weak UL signal. It is beneficial to reduce the interference before it reaches the analog RX chain. In another example, minimizing the average interference power on one or more UL antenna elements and / or minimizing the interference power based on UL beamforming can reduce the average interference per element or the interference after RX combining.

[0047] Figure 5 FIG. illustrates an example of a flowchart of a method 500 according to various example embodiments, which method 500 can be performed by a base station (such as Figure 13 the network entity 1310 shown in). The interference for configuration k can be represented by S(k).

[0048] At 501, method 500 can include calculating a beamforming coefficient vector w and / or selecting a beamforming coefficient vector from a codebook, or receiving an index of the beamforming coefficient vector from a UE in a CSI report.

[0049] At 502, method 500 can include estimating a channel coefficient h(m, n).

[0050] At 503, method 500 can include calculating interference for a first configuration or a second configuration according to Equation (1), Equation (2), and / or Equation (3).

[0051] Figure 6 FIG. depicts an example of an antenna array configuration in UL, DL, and a flexible time slot with two configurations. At 504, if S(1) < S(2), the method can include using the first configuration as shown and described with reference to the flexible time slot, i.e., Figure 4 configuration 1 shown in Figure 4 FIG. depicts an antenna array configuration in UL, DL, and a flexible time slot with two configurations. Alternatively, if S(1) ≥ S(2), the method can include using the second configuration, as shown, for example, in the flexible time slot, as Figure 4 configuration 2 shown in.

[0052] Figure 7 FIG. depicts various example embodiments of using two separate antenna panels to increase DL-UL isolation. In this embodiment, assuming that each panel has RX and TX capabilities, in the first configuration, the first panel can be configured for DL, and the second panel can be configured for UL. In the second configuration, UL and DL can be reversed.

[0053] Figure 8depicts certain example embodiments in which a network entity uses one of a first configuration and a second configuration having different numbers of antenna elements in UL and DL subsets. If S(1) < threshold, the network entity may use the first configuration; otherwise, the network entity may use the second configuration.

[0054] As described herein, Figure 5 the method can select an antenna configuration from the first configuration and the second configuration. In an example embodiment, the TX power applied to the antenna elements having the same polarization in the DL subset can be defined according to Equation (4) such that

[0055]

[0056] where p i can be the power of the i-th antenna element (e.g., Figure 4 ).

[0057] After selecting an antenna configuration from the first configuration and the second configuration, the method may further include: if S(m) > threshold_2, reducing S(m) by optimizing P1 and P2 selected at 504, where m is a configuration index.

[0058] CSI can be obtained in various ways in NR / 5G, including channel sounding and CSI reporting. For example, for CSI reporting, the base station can request the UE to perform measurements and provide reports. Two antenna configurations can be used in flexible time slots, where CSI information for the two configurations can be obtained. For example, in some example embodiments, the base station can report to the UE which antenna configuration is selected for each time interval (e.g., flexible time slot), and request a CSI report for one antenna configuration. Then the UE can calculate the CSI report based on the time interval in which the antenna configuration is consistent with the requested CSI report and issue the CSI report to the base station.

[0059] In various example embodiments, the base station can report to the UE which antenna configuration is selected for each time interval (e.g., flexible time slot), and request an SRS for one antenna configuration. Then the UE can transmit the SRS and the requested antenna configuration over the time interval. Note that using SRS in flexible time slots to obtain CSI information is not likely to be used because this may require periodic frequency resource switching in these time slots.

[0060] As Figure 9 shown, when the enumeration in the DL and UL subsets is independent, certain example embodiments can include the enumeration of antenna elements in flexible time slots.

[0061] Figure 10Illustrated is an example flowchart of some example embodiments. For example, the channel between the l-th TX antenna element and the m-th RX antenna element at a predefined TX frequency can be represented by representation. Figure 10 One or more operations of Figure 10 can be performed by a network entity configured to execute these operations, such as Figure 13 the network entity 1310 shown in Figure 13 , which may include a processor 1311 and a memory 1312.

[0062] The processor 1311 can be configured to determine the channel matrix H TX . In one example, the processor 1311 can be configured to determine the channel matrix according to Equation (5) such that

[0063]

[0064] where N TX can be the number of TX antenna elements, and N RX can be the number of RX antenna elements.

[0065] The processor 1311 can be configured to determine the covariance C TX of the channel matrix H TX . In one example, the processor 1311 can be configured to determine the covariance C TX of the channel matrix H TX (also denoted as ), such that

[0066] C TX = H TX (H TX ) H , (6)

[0067] where indicates the TX beamforming coefficient vector. Merely as some examples, the processor 1311 can be configured to determine the beamforming coefficient vector by: selecting the beamforming coefficient vector from a codebook (which can be stored in the memory, such as Figure 13 the memory 1312 shown in Figure 13 ), calculating or otherwise determining the beamforming coefficient vector using eigenvector decomposition, or obtaining the beamforming coefficient vector by any other method.

[0068] indicates the TX beamforming coefficient vector obtained by the transformation W TX . The objective of this transformation is to reduce interference. W TX can be obtained by recursive calculation according to Equation (7), such that

[0069] Wk+1 = f(W k , H TX ), (7)

[0070] where k = 0, …, N iter -1, N iter is the maximum number of iterations. The processor 1311 can initiate the calculation by setting the initial value of the transformed vector W0 to the untransformed vector w TX as follows:

[0071] W0 = w TX (8)

[0072] The processor 1311 can determine the transformation function f(W k , H TX ) according to equation (9) such that

[0073]

[0074] where ||w k || denotes the Euclidean norm. The processor 1311 can continue to perform iterative calculations until the maximum number of iterations N of the predefined target is reached iter , or until other stopping criteria are met. Example stopping criteria include the maximum interference at the RX antenna element. The processor 1311 can assume uniformity and can use equation (10) to determine the signal interference such that

[0075] I = (H TX ) H w TX . (10)

[0076] The processor 1311 can use equation (11) to determine the maximum interference such that

[0077]

[0078] where I k can be the k-th element of the vector I and can indicate the interference at the k-th antenna element. Equation (12) can be used to determine the stopping criterion such that

[0079]

[0080] where is the target value of the maximum interference. When this target value is reached, the iteration stops. The target value of the maximum interference is chosen to be low enough to avoid blocking or saturation of the RX RF circuit.

[0081] Each iteration can increase the suppression of interference and / or cause the transformed beamforming vector to deviate from the original beamforming vector. Thus, in some applications, an example stop criterion can include W k a deviation from w TX greater than a predefined threshold. This deviation level can be measured directly, for example, by the Euclidean distance or by the dot product of two vectors, or indirectly, for example, by the loss of beamforming gain.

[0082] In response to determining that E k is the Euclidean distance between the vector w TX and W k then,

[0083] e k = ||w TX - W k ||, (13)

[0084] Processor 1311 can be configured to use the stop criterion such that:

[0085]

[0086] where is the maximum acceptable value of the Euclidean distance. If this value is exceeded, then processor 1311 can be configured to stop performing iterative calculations, for example, Figure 10 one or more operations of.

[0087] As another example, processor 1311 can be configured to use logical operations (e.g., logical disjunction, logical conjunction, etc.) to cascade two or more stop criteria to form a new stop criterion, for example:

[0088]

[0089] where || indicates logical disjunction.

[0090] H TX is the channel matrix at a specific frequency in the TX band, typically the center frequency of the band. If the band is wide, then for frequencies significantly different from the center frequency, the estimation error results in worse interference cancellation. This can be overcome by introducing sub-bands and calculating the transformed beamforming coefficient vectors for each sub-band. By denotes the frequency vector, where N SB is the number of sub-bands. The elements f k of this vector are the center frequencies of the k-th sub-band. H TX (k) is the channel matrix at the frequency f k and W TX (k) is for H TX (k) and the same untransformed vector wTX The calculated transformed beamforming coefficient vector, W TX (k) is calculated for one or more subbands. In this way, more uniform suppression of interference is achieved across the entire frequency band.

[0091] Figure 11 Another example flowchart of some example embodiments is illustrated. For example, the channel between the l-th TX antenna element and the m-th RX antenna element at a predefined TX frequency can be represented by represented.

[0092] As at least referenced Figure 11 described, the processor 1311 can determine the interference channel matrix H TX (k) of an antenna array having multiple RX elements and multiple TX elements, where each element of the interference channel matrix indicates the physical channel between one uplink antenna element among the multiple uplink antenna elements and one downlink antenna element among the multiple downlink antenna elements. By way of example only, the processor 1311 can be configured to determine the beamforming coefficient vector by: selecting the beamforming coefficient vector from a codebook, calculating or otherwise determining the beamforming coefficient vector using eigenvector decomposition, or obtaining the beamforming coefficient vector by another method or combination of methods.

[0093] At block 1102, the processor 1311 can, for example, use the equation (6) described in reference Figure 11 to determine the covariance of the interference channel matrix.

[0094] At block 1104, the processor 1311 can set the number of iterations to zero. At block 1106, the processor 1311 can set the transformed beamforming coefficient vector W k to be equal to the untransformed beamforming coefficient vector w TX , where the untransformed beamforming coefficient vector W TX is determined by: using one or more of the initial conditions, determining from a codebook, or calculating in some conventional manner such as an eigenvector.

[0095] During the first iteration or the next iteration k, at block 1108, the processor 1311 can determine the new transformed transmit beamforming coefficient vector W k by determining the difference between the product of the covariance of the transformed beamforming coefficient vector W TX and the interference channel matrix C k and the transformed beamforming coefficient vector W Figure 10 (e.g., as provided in equation (9) described in at least reference k+1。At block 1110, the processor 1311 may normalize the new transformed beamforming coefficient vector W k+1 (e.g., as provided in equation (9) at least with reference to Figure 10 ).

[0096] At block 1112, the processor 1311 may determine whether the iteration number k is less than a predefined maximum iteration number N iter . In response to determining that the iteration number k is less than the predefined number, at block 1114, the processor 1311 may determine the interference I at each receiving element based on the new transformed beamforming coefficient vector W k+1 and the corresponding elements of the interference channel matrix (H TX ). H At block 1116, the processor 1311 may determine the power P of the interference at each receiving element based on the interference I at each receiving element

[0097] . In one example, the processor 1311 may use equation (16) to determine the power P of the interference at each receiving element k , such that k

[0098] P k = ||I k || 2 , (16)

[0099] At block 1118, the processor 1311 may select the maximum value I of the power P of the interference I k . In one example, the processor 1311 may be configured to select the maximum interference value based on equation (17), such that max

[0100]

[0101] Figure 10 At block 1120, the processor 1311 may determine whether the maximum interference I at the receiving antenna element is less than or equal to the maximum interference of a predefined target max (e.g., according to equation (12) at least with reference to ). In response to the maximum interference at the receiving antenna element being greater than the maximum interference of the predefined target, at block 1122, the processor 1311 may increment the iteration number k and return to blocks 1108 and 1110, where the new transformed transmit beamforming coefficient vector is determined. Figure 10

[0102] ​In response to one of the following: (i) the number of iterations is greater than a predefined number, or (ii) the maximum interference at the receiving antenna element is less than or equal to the maximum interference of a predefined target, the processor 1311 may be configured to, at block 1124, set the transmit beamforming coefficient vector W TX to be equal to the new transformed beamforming coefficient vector W k+1 . Then the processor 1311 may exit the process Figure 11 described. In other examples, the process Figure 11 may be repeated in response to one or more operating conditions

[0103] In one example, after one or more operations of blocks 1102 to 1124 are completed, the processor 1311 may be configured to cause the antenna array to operate according to the new transformed beamforming coefficient vector

[0104] Figure 12 depicts an example of hardware that may be used in various example embodiments. In particular Figure 12 illustrates that the processes described herein may be performed as part of a beamforming vector recomputation module before or after an inverse fast Fourier transform (IFFT) during beamforming operations. As Figure 12 shown, a radio frequency integrated circuit (RFIC) may communicate with a digital front end (DFE) and an analog front end (FE). The DFE, RFIC, and analog FE may perform any one of IFFT, digital upconversion, peak factor reduction, digital predistortion, digital-to-analog conversion, power amplification, analog upconversion, and / or digital and analog filtering. Additionally Figure 12 illustrates L1 blocks for processing the NR / 5G PDSCH channel. The blocks shown in a) may perform beamforming in the frequency domain, while the blocks shown in b) may perform beamforming in the time domain

[0105] Figure 13 illustrates an example of a system according to certain example embodiments. In one example embodiment, the system may include multiple devices, such as, for example, a network entity 1310 and / or a UE 1320

[0106] The network entity 11310 may be one or more of a base station (e.g., a 3G UMTS NodeB, a 4G LTE evolved NodeB, or a 5G NR next-generation NodeB), a serving gateway, a server, and / or any other access node or a combination thereof

[0107] The network entity 1310 may also include at least one gNB centralized unit (CU) that may be associated with at least one gNB distributed unit (DU). The at least one gNB-CU and the at least one gNB-DU may communicate via the Fifth Generation Core (5GC) via at least one F1 interface, at least one X n -C interface, and / or at least one NG interface.

[0108] The UE 1320 may include one or more mobile devices, such as a mobile phone, a smart phone, a personal digital assistant (PDA), a tablet computer or a portable media player, a digital camera, a pocket video camera, a video game console, a navigation unit (such as a Global Positioning System (GPS) device), a desktop or a laptop computer, a single positioning device (such as a sensor or a smart meter), or any combination thereof. Additionally, the network entity 1310 and / or the UE 1320 may be one or more Citizen Broadband Radio Service Devices (CBSD).

[0109] The network entity 1310 and / or the UE 1320 may include at least one processor, correspondingly denoted as 1311 and 1321. The processors 1311 and 1321 may be embodied by any computing or data processing device, such as a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), or a similar device. The processor may be implemented as a single controller, or multiple controllers or processors.

[0110] As shown at 1312 and 1322, at least one memory may be provided in one or more devices. The memory may be fixed or removable. The memory may include computer program instructions or computer code contained therein. The memories 1312 and 1322 may independently be any suitable storage device, such as a non-transitory computer-readable medium. The term "non-transitory" as used herein may correspond to a limitation on the medium itself (i.e., tangible, rather than a signal), rather than a limitation on the persistence of data storage (e.g., Random Access Memory (RAM) versus Read-Only Memory (ROM)). A hard disk drive (HDD), Random Access Memory (RAM), flash memory, or other suitable memory may be used. The memory may be combined on a single integrated circuit as a processor, or may be separated from one or more processors. Additionally, the computer program instructions stored in the memory and executable by the processor may be in any suitable form of computer program code, e.g., compiled or interpreted computer programs written in any suitable programming language.

[0111] The processors 1311 and 1321, the memories 1312 and 1322, and any subset thereof may be configured to provide with Figures 2 to 12components corresponding to the respective boxes. Although not shown, the device may also include positioning hardware, such as GPS or microelectromechanical systems (MEMS) hardware, which may be used to determine the location of the device. Other sensors are also permitted and may be configured to determine location, altitude, speed, orientation, etc., such as a barometer, compass, etc.

[0112] As Figure 13 shown, transceivers 1313 and 1323 may be provided, and one or more devices may also include at least one antenna, correspondingly shown as 1314 and 1324. The device may have many antennas, such as an antenna array configured for multiple-input multiple-output (MIMO) communication, or multiple antennas for multiple radio access technologies (RATs). For example, other configurations of these devices may be provided. Transceivers 1313 and 1323 may be transmitters, receivers, both transmitters and receivers, or units or devices that may be configured for both transmission and reception.

[0113] The memory and computer program instructions may be configured to, together with a processor of a particular device, cause a hardware device (such as a UE) to perform any of the processes described herein (i.e., Figures 2 to 12 ). Thus, in certain example embodiments, a non-transitory computer-readable medium may be encoded with computer instructions that, when executed in hardware, perform a process, such as one of the processes described herein. Alternatively, certain example embodiments may be executed entirely in hardware.

[0114] In certain example embodiments, an apparatus may include means configured to perform Figures 2 to 12The circuitry of any process or function shown. As used in this application, the term "circuitry" can refer to one or more or all of the following: (a) a hardware-only circuit implementation (such as an implementation only in analog and / or digital circuitry), (b) a combination of hardware circuitry and software, such as (where applicable): (i) a combination of (one or more) analog and / or digital hardware circuitry and software / firmware, and (ii) any part of (one or more) hardware processors (including (one or more) digital signal processors), software, and (one or more) memories that work together to cause a device (such as a mobile phone or a server) to perform various functions), and (c) (one or more) hardware circuitry and / or (one or more) processors, such as (one or more) microprocessors or a part of (one or more) microprocessors, that require software (e.g., firmware) to operate, but the software may be absent when it is not required to operate. This definition of circuitry applies to all uses of the term in this application, including in any claim. As a further example, as used in this application, the term "circuitry" also encompasses an implementation of only hardware circuitry or a processor (or processors) or a part of hardware circuitry or processing and its accompanying software and / or firmware. For example, if applicable to a particular claim element, the term "circuitry" also encompasses a baseband integrated circuit or a processor integrated circuit for a mobile device, or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

[0115] Figure 14 An example of a 5G network and system architecture according to certain example embodiments is shown. A plurality of network functions are shown, which can be implemented as software operating as part of a network device or dedicated hardware, as the network device itself or dedicated hardware, or as a virtual function operating as a network device or dedicated hardware. Figure 14 The network entities and UEs shown can correspondingly be similar to network entity 1310 and UE 1320. A user plane function (UPF) can provide services such as mobility within and between RATs, routing and forwarding of data packets, inspection of packets, user plane quality of service (QoS) handling, buffering of downlink packets, and / or triggering of downlink data notifications. An application function (AF) can be mainly connected to the core network through an interface to facilitate application usage of service routing and interact with the policy framework.

[0116] According to certain example embodiments, processors 1311 and 1321 and memories 1312 and 1322 can be included in a processing circuitry or a control circuitry, or can form a part of the processing circuitry or the control circuitry. Additionally, in some example embodiments, transceivers 1313 and 1323 can be included in a transceiver circuitry, or can form a part of the transceiver circuitry.

[0117] In some example embodiments, an apparatus (e.g., network entity 1310 and / or UE 1320) may include components for performing the methods, procedures, or any variations thereof discussed herein. Examples of such components may include one or more processors, memories, controllers, transmitters, receivers, and / or computer program code for causing the execution of operations.

[0118] The features, structures, or characteristics of the example embodiments described throughout this specification may be combined in any suitable manner in one or more example embodiments. For example, the use throughout this specification of phrases such as "various embodiments", "certain embodiments", "some embodiments", or other similar language refers to the fact that a particular feature, structure, or characteristic described in connection with the example embodiments may be included in at least one example embodiment. Thus, the appearances of the phrases "in various embodiments", "in certain embodiments", "in some embodiments", or other similar language throughout this specification are not necessarily all referring to the same group of example embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments.

[0119] As used herein, "at least one of the following: <list of two or more elements>" and "at least one of <list of two or more elements>" and similar phrases (where the list of two or more elements is joined by "and" or "or") mean at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0120] Additionally, if desired, the different functions or procedures discussed in this disclosure may be performed in a different order and / or simultaneously with each other. Further, if desired, one or more of the described functions or procedures may be optional or may be combined. Accordingly, the description of this disclosure should be regarded as illustrative of the principles and teachings of certain example embodiments and not as a limitation thereof.

[0121] Those of ordinary skill in the art will readily understand that the example embodiments discussed in this disclosure may be practiced with processes in different orders and / or with hardware elements in configurations different from those disclosed. Thus, although some embodiments have been described based on these example embodiments, it will be apparent to those skilled in the art that certain modifications, variations, and alternative configurations will be apparent when staying within the spirit and scope of the example embodiments.

Claims

1. A method for communication, comprising: Determining an interference channel matrix of an antenna array having a plurality of uplink antenna elements and a plurality of downlink antenna elements, wherein each element of the interference channel matrix indicates a physical channel between one uplink antenna element among the plurality of uplink antenna elements and one downlink antenna element among the plurality of downlink antenna elements; Determining an untransformed beamforming coefficient vector; Using the untransformed beamforming coefficient vector and the interference channel matrix to determine (1108) a transformed beamforming coefficient vector; Using the transformed beamforming coefficient vector to determine (1114) the interference at each receiving element of the plurality of uplink antenna elements and the plurality of downlink antenna elements, and determining (1116) the power of the interference at each receiving element of the plurality of uplink antenna elements and the plurality of downlink antenna elements; Determining (1120) the maximum interference of the antenna array as the maximum value of the power of the interference determined at each receiving element; And Operating (1124) the antenna array based on the transformed beamforming coefficient vector in response to the maximum interference being less than or equal to a maximum interference of a predefined target.

2. The method according to claim 1, further comprising: In response to the maximum interference being greater than the maximum interference of a predefined target, using the transformed beamforming coefficient vector and the interference channel matrix to determine a new transformed beamforming coefficient vector.

3. The method according to claim 1, wherein the transformed beamforming coefficient vector is calculated by minimizing at least one of the following: The maximum interference power on one or more uplink antenna elements; The average interference power on one or more uplink antenna elements; or The interference power based on uplink beamforming.

4. The method according to claim 3, wherein: Minimizing the maximum interference power is based on the maximum interference power from one or more downlink antenna elements to a given uplink antenna element among the plurality of uplink antenna elements; Minimizing the average interference power from one or more downlink antenna elements to a given uplink antenna element among the plurality of uplink antenna elements includes: determining the average interference power; or Minimizing the interference power includes: applying an uplink beamforming vector.

5. The method according to claim 1, further comprising: Selecting at least one downlink beamforming coefficient vector from at least one codebook.

6. The method according to claim 1, further comprising: Receiving, in a channel state information report, at least one index of at least one downlink beamforming coefficient vector from a user equipment.

7. The method according to claim 1, further comprising: Determining interference powers corresponding to a plurality of configurations, and selecting a configuration from the plurality of configurations based on the determined interference powers, wherein the selected configuration includes at least one of the following: Antenna array configurations in an uplink time slot, a downlink time slot, and a flexible time slot, and the antenna array configuration in the flexible time slot includes two configurations.

8. The method according to claim 7, wherein the selected configuration comprises: Enumeration of antenna elements in sub-band non-overlapping full-duplex time slots.

9. The method according to claim 8, wherein the enumeration of the antenna elements in the downlink and uplink subsets is independent.

10. A device for communication, comprising: means for determining an interference channel matrix of an antenna array having a plurality of uplink antenna elements and a plurality of downlink antenna elements, wherein each element of the interference channel matrix indicates a physical channel between one uplink antenna element among the plurality of uplink antenna elements and one downlink antenna element among the plurality of downlink antenna elements; means for determining an untransformed beamforming coefficient vector; means for using the untransformed beamforming coefficient vector and the interference channel matrix to determine a transformed beamforming coefficient vector; means for using the transformed beamforming coefficient vector to determine the interference at each receiving element of the plurality of uplink antenna elements and the plurality of downlink antenna elements, and determining the power of the interference at each receiving element of the plurality of uplink antenna elements and the plurality of downlink antenna elements; means for determining the maximum interference of the antenna array based on the power of the interference determined at each receiving element; and means for operating the antenna array based on the transformed beamforming coefficient vector in response to the maximum interference being less than or equal to a predefined target maximum interference.

11. The device according to claim 10, further comprising: means for determining a new transformed beamforming coefficient vector using the transformed beamforming coefficient vector and the interference channel matrix in response to the maximum interference being greater than a predefined target maximum interference.

12. The device according to claim 10, wherein the transformed beamforming coefficient vector is calculated by minimizing at least one of the following: the maximum interference power on one or more uplink antenna elements; the average interference power on one or more uplink antenna elements; or the interference power based on uplink beamforming.

13. The device according to claim 12, wherein: the maximum interference power is minimized based on the maximum interference power from one or more downlink antenna elements to a given uplink antenna element among the plurality of uplink antenna elements; the average interference power from one or more downlink antenna elements to a given uplink antenna element among the plurality of uplink antenna elements is minimized by determining the average interference power; or the interference power is minimized by applying an uplink beamforming vector.

14. The device according to claim 10, further comprising: means for selecting at least one downlink beamforming coefficient vector from at least one codebook.

15. The device according to claim 10, further comprising: means for receiving at least one index of at least one downlink beamforming coefficient vector from a user equipment in a channel state information report.

16. The device according to claim 10 further comprises: A component for determining interference power corresponding to multiple configurations and selecting a configuration from the multiple configurations based on the determined interference power, wherein the selected configuration includes at least one of the following: Antenna array configurations in uplink time slots, downlink time slots, and flexible time slots, wherein the antenna array configuration in the flexible time slot includes two configurations.

17. The apparatus according to claim 16, wherein the selected configuration comprises: Enumeration of antenna elements in sub-band non-overlapping full-duplex time slots.

18. The apparatus according to claim 17, wherein the enumeration of antenna elements in the downlink and uplink subsets is independent.

19. An apparatus for communication, comprising: At least one processor; And At least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least perform the method according to any one of claims 1 to 9.

20. A non-transitory computer-readable medium comprising program instructions that, when executed by a device, cause the device to at least perform the method according to any one of claims 1 to 9.

21. An apparatus for communication, comprising circuitry configured to perform the method according to any one of claims 1 to 9.

22. A computer program product comprising instructions that, when executed by a device, cause the device to perform the method according to any one of claims 1 to 9.

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