Protecting downlink control information in cellular communication networks

Abstract

According to an example aspect of the present invention, a method is provided, comprising: determining at least one possible downlink control information for scheduling data transmission by a user equipment, checking a scrambled version of the at least one possible downlink control information to determine whether the scrambled version of the at least one possible downlink control information defines valid downlink control information, sending the scrambled version of the at least one possible downlink control information, and scheduling data transmission based on the at least one possible downlink control information, and if it is determined that the scrambled version of the at least one possible downlink control information defines valid downlink control information, scheduling interfering transmission based on the scrambled version of the at least one possible downlink control information.

Description

Technical Field

[0001] Various example embodiments relate generally to cellular communication networks and, more particularly, to protecting downlink control information in such networks. Background Art

[0002] In various cellular networks, such as those operating according to Long Term Evolution (LTE) and / or 5G radio access technology, downlink control information is required to at least inform user equipment (UE) of its resource allocation. 5G radio access technology may also be referred to as New Radio (NR) access technology. LTE has been widely deployed since its introduction and is still under development by the Third Generation Partnership Project (3GPP). Similarly, 3GPP has also developed standards for 5G / NR. One of the topics under discussion in 3GPP is security, and since downlink control information informs UEs of their resource allocation, there is a need to provide improved methods, apparatus, and computer programs for protecting downlink control information in wireless networks. Summary of the Invention

[0003] According to some aspects, the subject matter of the independent claims is provided. Some embodiments are defined in the dependent claims. The scope of protection sought by various embodiments of the present invention is given by the independent claims. The embodiments, examples, and features described in this specification that do not fall within the scope of the independent claims (if any) are to be construed as examples useful for understanding the various embodiments of the present invention.

[0004] According to a first aspect of the present invention, a first method for a base station is provided for scheduling data transmission for a user equipment and interference transmission for an eavesdropper using a single downlink control channel transmission, the first method comprising: determining at least one possible downlink control information for the user equipment to schedule the data transmission; checking a scrambled version of the at least one possible downlink control information to determine whether the scrambled version of the at least one possible downlink control information defines valid downlink control information; sending a scrambled version of the at least one possible downlink control information and scheduling the data transmission based on the at least one possible downlink control information; and if it is determined that the scrambled version of the at least one possible downlink control information defines valid downlink control information, scheduling the interference transmission based on the scrambled version of the at least one possible downlink control information.

[0005] In some embodiments, the scrambled version of the at least one possible downlink control information may indicate at least a resource allocation for the user equipment after descrambling, and the effective downlink control information defined by the scrambled downlink control information includes at least a resource allocation for the interfering transmission.

[0006] In some embodiments, the first method may further comprise scrambling the at least one possible downlink control information using a physical layer security key associated with the user equipment.

[0007] In some embodiments, the first method may further comprise deciding not to schedule the interfering transmission based on the scrambled version of the at least one possible downlink control information if it is determined that the scrambled version of the at least one possible downlink control information does not define valid downlink control information.

[0008] In some embodiments, the effective downlink control information may at least indicate time and frequency resources controlled by the base station.

[0009] In some embodiments, the first method may further include: if it is determined that the scrambled version of the at least one downlink control information does not indicate valid downlink control information, allocating another possible downlink control information for the user equipment; checking the scrambled version of the another possible downlink control information to determine whether the scrambled version of the another possible downlink control information defines another valid downlink control information; and sending the scrambled version of the another possible downlink control information to the user equipment, and scheduling the data transmission based on the another possible downlink control information.

[0010] In some embodiments, the first method may further include: sending data to the user equipment on resources indicated by the at least one possible downlink control information for the user equipment; and sending an interference message on resources indicated by the valid downlink control information.

[0011] In some embodiments, the first method may further comprise: receiving a data transmission on resources indicated by at least one possible downlink control information for the user equipment; and identifying a security threat based on the transmission received on the resources indicated by the valid downlink control information.

[0012] In some embodiments, the first method may further include: scrambling the at least one possible downlink control information using a first scrambling sequence to obtain a scrambled version of the at least one possible downlink control information; and scrambling cyclic redundancy check bits of the scrambled version of the at least one possible downlink control information using a second scrambling sequence. The first method may further include: selecting the second scrambling sequence from a sequence set, wherein the sequence set corresponds to a physical layer security key associated with the user equipment.

[0013] In some embodiments, the first method may further comprise: if the selected second scrambling sequence does not define the valid downlink control information together with the scrambled downlink control information, changing the second scrambling sequence.

[0014] In some embodiments, the first method may further comprise determining that the scrambled version of the at least one possible downlink control information for the user equipment defines valid downlink control information by identifying a possibility of scheduling another transmission by the base station.

[0015] According to a second aspect of the present invention, a second method for a user equipment is provided, the second method comprising: receiving a scrambled version of at least one downlink control information of the user equipment; decoding the scrambled version of the at least one downlink control information; determining that the decoded scrambled version of the at least one downlink control information provides valid downlink control information for an interference transmission; sending data on resources indicated by the at least one downlink control information; and sending the interference transmission on the resources indicated by the valid downlink control information.

[0016] In some embodiments, the second method may further include: after the decoding, descrambling a scrambled version of the at least one downlink control information to determine the at least one downlink control information.

[0017] In some embodiments, the second method may further comprise descrambling a scrambled version of at least one downlink control information of the user equipment using a physical layer security key associated with the user equipment.

[0018] According to a third aspect of the present invention, there is provided an apparatus for scheduling data transmission for a user equipment and interference transmission for an eavesdropper using a single downlink control channel transmission, the apparatus comprising: a component for determining at least one possible downlink control information for the user equipment to schedule the data transmission; a component for checking a scrambled version of the at least one possible downlink control information to determine whether the scrambled version of the at least one possible downlink control information defines valid downlink control information; a component for sending the scrambled version of the at least one possible downlink control information, and a component for scheduling the data transmission based on the at least one possible downlink control information; and a component for scheduling the interference transmission based on the scrambled version of the at least one possible downlink control information if it is determined that the scrambled version of the at least one possible downlink control information defines valid downlink control information. According to the third aspect, the apparatus may be a base station. The apparatus may include a component for performing the first method.

[0019] According to a fourth aspect of the present invention, there is provided an apparatus comprising: means for receiving a scrambled version of at least one downlink control information of a user equipment; means for decoding the scrambled version of the at least one downlink control information; means for determining that the decoded scrambled version of the at least one downlink control information provides effective downlink control information for an interfering transmission; means for sending data on resources indicated by the at least one downlink control information; and means for sending the interfering transmission on resources indicated by the effective downlink control information. According to the fourth aspect, the apparatus may be a user equipment. The apparatus may include means for performing the second method.

[0020] According to a fifth aspect of the present invention, there is provided an apparatus for scheduling data transmission for a user equipment and interference transmission for an eavesdropper using a single downlink control channel transmission, the apparatus comprising at least one processing core, at least one memory, wherein the at least one memory comprises computer program code, the at least one memory and the computer program code being configured to, together with the at least one processing core, cause the apparatus to at least perform: determining at least one possible downlink control information for the user equipment to schedule the data transmission; checking a scrambled version of the at least one possible downlink control information to determine whether the scrambled version of the at least one possible downlink control information defines valid downlink control information; sending the scrambled version of the at least one possible downlink control information and scheduling the data transmission based on the at least one possible downlink control information; and if it is determined that the scrambled version of the at least one possible downlink control information defines valid downlink control information, scheduling the interference transmission based on the scrambled version of the at least one possible downlink control information. According to the fifth aspect, the apparatus may be a base station. The at least one memory and the computer program code may be configured to, together with the at least one processing core, cause the apparatus to at least perform the first method.

[0021] According to a sixth aspect of the present invention, there is provided an apparatus comprising at least one processing core and at least one memory, wherein the at least one memory comprises computer program code, the at least one memory and the computer program code being configured to, together with the at least one processing core, cause the apparatus to at least perform: receiving a scrambled version of at least one downlink control information of the user equipment; decoding the scrambled version of the at least one downlink control information; determining that the decoded scrambled version of the at least one downlink control information provides valid downlink control information for an interfering transmission; sending data on the resources indicated by the at least one downlink control information; and sending the interfering transmission on the resources indicated by the valid downlink control information. According to the sixth aspect, the apparatus may be a user equipment. The at least one memory and the computer program code may be configured to, together with the at least one processing core, cause the apparatus to at least perform the second method.

[0022] According to a seventh aspect of the present invention, there is provided a non-transitory computer-readable medium having stored thereon a set of computer-readable instructions, which, when executed by at least one processor, cause an apparatus to perform at least the first method.

[0023] According to an eighth aspect of the present invention, there is provided a non-transitory computer-readable medium having stored thereon a set of computer-readable instructions, which, when executed by at least one processor, cause an apparatus to perform at least the second method.

[0024] According to a ninth aspect of the present invention, there is provided a computer program configured to execute the first method. According to a tenth aspect of the present invention, there is provided a computer program configured to execute the second method. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 illustrates an exemplary network scenario according to at least some embodiments of the present invention;

[0026] Figure 2 Protection of downlink control information according to at least some embodiments of the present invention is shown;

[0027] Figure 3 Protection of downlink control information and CRC is shown according to at least some embodiments of the present invention;

[0028] Figure 4 An exemplary process according to at least some embodiments of the present invention is shown;

[0029] Figure 5 shows example apparatus capable of supporting at least some embodiments of the present invention;

[0030] Figure 6A flowchart illustrating a first method according to at least some embodiments of the present invention; and

[0031] Figure 7 A flow chart of a second method according to at least some embodiments of the present invention is shown. DETAILED DESCRIPTION

[0032] The security of downlink control information in a cellular communication network may be improved by the processes described herein. In some embodiments of the present invention, possible downlink control information for a first user equipment (UE) may be scrambled, and a scrambled version of the possible downlink control information may be checked to ensure that the scrambled version of the possible downlink control information for the first UE defines valid downlink control information, and if so, an interfering transmission may be scheduled based on the scrambled version of the possible downlink control information.

[0033] Therefore, the scrambled version of the downlink control information can be decoded by an eavesdropper (such as the second UE). That is, the eavesdropper can decode the scrambled version of the possible downlink control information to identify the downlink control information associated with the interfering transmission. The eavesdropper may therefore decode the misleading resource allocation. Therefore, for example, in the case of downlink data transmission, the base station BS can send data to the first UE on the resources allocated to the first UE. The BS can also send an interfering transmission on the interfering resources, such as some other data or a dummy transmission block, to mislead the eavesdropper. Similarly, in the case of uplink data transmission, the first UE can send data to the BS on the resources allocated to the first UE and perform an interfering transmission on the interfering resources to mislead the eavesdropper.

[0034] Figure 1 An exemplary network scenario is shown in accordance with at least some embodiments of the present invention. Figure 1 An exemplary network scenario may include a first UE 110, a second UE 120, a BS 130, and a core network 140. The first UE 110 and the second UE 120 may include, for example, smartphones, cellular phones, machine-to-machine (M2M) nodes, machine-type communication (MTC) nodes, Internet of Things (IoT) nodes, car telemetry units, laptops, tablet computers, or virtually any kind of suitable wireless user equipment or mobile station (i.e., terminal).

[0035] exist Figure 1In an exemplary network scenario system, a first UE 110 may be attached to or connected to a BS 130 via an air interface 115 for wireless communication. BS 130 may be considered, for example, a serving BS for first UE 110. The air interface 115 between the first UE 110 and the BS 130 may be configured according to a radio access technology (RAT) that both the first UE 110 and the BS 130 are configured to support. The air interface 115 may include, for example, one or more beams between the first UE 110 and the BS 130.

[0036] Examples of cellular RATs include Long Term Evolution (LTE), New Radio (NR) (also known as fifth generation 5G), and MulteFire. For example, in the context of LTE, BS 130 may be referred to as an eNB, while in the context of NR, BS 130 may be referred to as a gNB. In any case, embodiments of the present invention are not limited to any particular wireless technology. Rather, embodiments of the present invention may be used in any wireless communication system where it is desired to protect downlink control information.

[0037] BS 130 may be connected to core network 140 directly or through at least one intermediate node. BS 130 may be connected to core network 140 through wired connection 135. Core network 140, in turn, may be connected to another network (e.g., a global interconnection network) through a global interconnection network. Figure 1 (not shown) coupling, so that connection to other networks can be obtained.

[0038] In some embodiments of the present invention, the first UE 110 and the BS 130 may be legitimate participants in the communication, while the second UE 120 may be a potential eavesdropper. That is, the first UE 110 and the BS 130 wish to communicate securely over the air interface 115, while the second UE 120 may attempt to intercept and decrypt the communication between the BS 130 and the first UE 110, even though the second UE 120 is not the legitimate recipient of the communication.

[0039] Figure 1 An exemplary network scenario is shown in which an eavesdropper (such as a second UE 120) attempts to monitor and decode data transmissions between a BS 130 (such as a gNB) and a first UE 110. Especially when the data transmissions between the BS 130 and the first UE 110 are performed over a long period of time, it becomes feasible to break the high-level security protocols and decode accurate information.

[0040] Therefore, the security of data transmission over wireless networks remains an important issue. For example, it is crucial to ensure that private data can only be accessed by legitimate recipients (such as the first UE 110) and not by eavesdroppers and imposters (such as the second UE 120). In many cases, jamming and eavesdropping are two major attacks on the physical layer of wireless networks.

[0041] In some embodiments of the present invention, BS 130 may protect downlink control channel transmissions (such as a physical downlink control channel (PDCCH)) by encrypting (i.e., scrambling) downlink control information for first UE 110. That is, BS 120 (such as a gNB) may encrypt bits transmitted on the PDCCH. Typically, downlink control information may refer to downlink control information (DCI), such as that specified in the 3rd Generation Partnership Project (3GPP) standard specifications.

[0042] For example, in the case of downlink data transmission, a single downlink control channel transmission sent by BS 130 can be used to ensure that a scrambled version of the possible downlink control information schedules a downlink shared channel (such as a physical downlink shared channel (PDSCH)) for first UE 110 and another downlink shared channel (such as an interference resource) for misleading an eavesdropper (such as second UE 120). Similarly, in the case of uplink data transmission, a single downlink control channel transmission can be used to ensure that a scrambled version of the possible downlink control information schedules an uplink shared channel (such as a physical uplink shared channel (PUSCH)) for first UE 110 and another uplink shared channel (i.e., an interference resource) for misleading an eavesdropper (such as second UE 120).

[0043] In addition, physical layer security (PLS) can be used to improve the confidentiality of wireless communications. PLS utilizes the inherent randomness of the transmission channel, for example, the uniqueness of the channel model between two physical locations in space and time. For example, the physical parameters can evolve randomly in less than a second to ensure the security of the physical layer. The PLS key used for encryption can be based on the transmission channel, arrival direction / departure direction, transmit beam index / receive beam index, path loss, etc. For example, the PLS key associated with or belonging to the first UE 110 can refer to a key derived based on the transmission channel between the first UE 110 and the BS 130. The PLS key of the first UE 110 can be derived separately at both the first UE 110 and the BS 130, for example, by assuming the reciprocity of the transmission channel between the first UE 110 and the BS 130.

[0044] PLS can be used to create an additional protection barrier, for example, to prevent the success of various attacks. In addition, PLS can be a good alternative to higher-level security protocols because the confidentiality of communications can be ensured without the need for a prior distribution of security keys. Therefore, additional information exchanges can be avoided. For example, symmetric key cryptosystems may be computationally efficient, but such cryptosystems cause delays and reduce throughput. On the other hand, public key algorithms are computationally intensive and energy-consuming while causing delays and reduced throughput. Therefore, PLS is suitable for example for Internet of Things (IoT) devices, because IoT devices typically have limited resources (e.g., processing power, communication capabilities, and battery). For both embedded solutions and communication standards, the security of IoT devices has evolved from a dispensable add-on to a must-have component because of the large number of attacks, such as those against connected cars or connected medical devices.

[0045] Therefore, there is a need to design new and robust security protocols based on PLS. For emerging wireless communication networks such as 5G / NR networks, currently used application layer solutions appear to be inefficient and insecure. Therefore, PLS can be used as an alternative or to provide an additional level of protection to form a well-integrated security solution with other solutions, effectively protecting the confidentiality and privacy of data communications in, for example, 5G / NR wireless networks.

[0046] Therefore, although the embodiments of the present invention can be applied to any wireless communication system that wishes to protect downlink control information, it should be recognized that, at least in the case of 5G / NR, it is necessary to use PLS to enhance security at the physical layer. For example, at least one challenge in current 5G / NR networks is that there is no solution to provide an additional level of security for data transmission.

[0047] Some embodiments of the present invention address the above challenges by providing a security solution, wherein the uniqueness of the wireless channel and / or the transmitted signal can be exploited by scrambling the downlink control information using a PLS key, thereby achieving secure communication and avoiding interference and eavesdropping.

[0048] Figure 2 Protection of downlink control information according to at least some embodiments of the present invention is shown. Figure 2In the embodiment of the present invention, DCI is represented by 210, the scrambling sequence generated by PLS is represented by 220, the scrambled DCI 210 is represented by 230, and the cyclic redundancy check CRC of the scrambled DCI 230 is represented by 240. DCI 210 can generally be referred to as downlink control information of a user equipment (such as the first UE 110). The scrambling sequence generated by PLS can also be referred to as a PLS key. In some embodiments of the present invention, the scrambled DCI 230 can be referred to as a scrambled version of DCI 210.

[0049] DCI 210 may be used for subsequent downlink data transmission or uplink data transmission, such as PDSCH or PUSCH, respectively, and DCI 210 may be transmitted on, for example, a PDCCH. In general, a PDCCH may be referred to as a single downlink control channel transmission. For transmission of DCI 210, BS 130 may encrypt (i.e., scramble) DCI 210 by encrypting at least some bits transmitted on the PDCCH to employ data protection. DCI 210 may also be referred to as a possible DCI for first UE 110.

[0050] Taking resource allocation for downlink data transmission as an example, BS 130 may use DCI 210 of first UE 110 and scramble DCI 210 using a PLS key associated with UE 110. That is, BS 130 may scramble DCI 210 using a scrambling sequence generated by PLS 220, where the scrambling sequence generated by PLS 220 is available at UE 110 and BS 130. Therefore, BS 130 may generate scrambled DCI 230 based on DCI 210 and the scrambling sequence generated by PLS 220.

[0051] After generating the scrambled DCI 230, the BS 130 may generate a CRC 240 by calculating a CRC value on the scrambled DCI 230. In addition, the BS 130 may append the CRC 240 (such as a distributed CRC in NR) to the scrambled DCI 230 and encode the scrambled DCI 230 together with the CRC 240. Since the CRC 240 may be appended to the scrambled DCI 230, both the first UE 110 and the second UE 120 may calculate a CRC value upon receiving the scrambled DCI 230 and the CRC 240, and determine that the CRC has passed if decoding of the scrambled DCI 230 is successful, i.e., the calculated CRC value corresponds to the CRC 240.

[0052] In some embodiments of the present invention, BS 130 may ensure that scrambled DCI 230 provides at least one valid resource assignment or allocation for an interfering resource (i.e., an interfering transmission). The interfering resource may be a combination of time and frequency resources, possibly controlled by BS 130. That is, BS 130 may determine whether the interfering resource can be scheduled based on the scrambled DCI 230. The scrambled DCI (i.e., the unscrambled DCI 230) may indicate the interfering resource. That is, if an eavesdropper decodes the scrambled DCI 230 without descrambling, the decoded scrambled DCI 230 may indicate the interfering resource. After generating the scrambled DCI 230 and determining that the interfering resource can be scheduled, BS 130 may schedule the interfering transmission based on the scrambled DCI 230.

[0053] The scrambled DCI 230 may then be transmitted. Thus, if an eavesdropper (such as second UE 120) receives the scrambled DCI 230 and attempts to decode it, decoding may succeed even without descrambling. Consequently, second UE 120 may determine resource allocation for interfering resources based on the decoded scrambled DCI 230 and assume that data transmission to or from first UE 110 will occur on interfering resources.

[0054] In addition, BS 130 may ensure that scrambled DCI 230 provides other DCI fields without requiring descrambling, so that any eavesdropper (such as second UE 120) can successfully decode the downlink shared channel indicated by the at least one valid interfering resource assignment. For example, BS 130 may determine that scrambled DCI 230 provides at least one interfering resource assignment without requiring descrambling, for example, by inspecting that decoded scrambled DCI 230 defines at least one valid interfering resource assignment that does not even require descrambling by any eavesdropper. BS 130 may also transmit a downlink shared channel, such as a PDSCH, on the at least one valid interfering resource to ensure that at least one data transmission is also present in the fields defined by decoded scrambled DCI 230, even without requiring descrambling. For example, an interference message may be transmitted on the at least one valid interfering resource instead of transmitting the actual data for first UE 110.

[0055] Alternatively, or in addition, only some, but not all, fields in DCI 210 may be scrambled to obtain scrambled DCI 230. That is, only a portion of DCI 210 may be scrambled using the PLS key associated with first UE 110 to generate scrambled DCI 230, and thus scrambled DCI 230 may include unscrambled portions. Thus, greater flexibility may be provided for scheduling of BS 130.

[0056] In addition, in some embodiments of the present invention, multi-UE scenarios with security requirements can be addressed. For example, BS 130 can send multiple scrambled DCIs, where each scrambled DCI is associated with a different UE and is scrambled using the PLS key of the associated UE. That is, each UE can have a different DCI payload. In this case, BS 130 can also ensure that the transmission of multiple scrambled DCIs defines at least one valid interference resource allocation without the need for descrambling, thereby saving overhead by not allocating multiple interference resources (such as interfering PDSCHs).

[0057] After generating the scrambled DCI 230 and possibly the CRC 240, the BS 130 may transmit two downlink shared channels, such as the PDSCH. For example, the BS 130 may transmit data to the first UE 110 on the resources indicated by the scrambled DCI 230 (i.e., on the resources indicated by the DCI 210) after descrambling. That is, the data may be data destined for the first UE 110, and the resources indicated by the scrambled DCI 230 after being descrambled may be the actual content of the DCI 210. In addition, the BS 130 may transmit an interference message for an eavesdropper (such as the second UE 120) on the resources indicated by the scrambled but not descrambled DCI 230, i.e., the eavesdropper only decodes the scrambled DCI 230 without descrambling it. Therefore, the eavesdropper may be misled by transmitting the interference message on the interfering resources.

[0058] The first UE 110 may then, upon receiving the scrambled DCI 230, decode the scrambled DCI 230 and descramble the decoded scrambled DCI using the PLS key associated with the first UE 110. Thus, after decoding and descrambling, the first UE 110 may recover the actual DCI 210 and identify the resources indicated by the scrambled DCI 230. Thus, the first UE 110 may receive data from the BS 130 on the resources indicated by the DCI 210 and, for example, decode the correct downlink shared channel (such as the PDSCH) transmission from the BS 130. That is, the first UE 110 may communicate with the BS 130 on the resources indicated by the DCI 210 (i.e., the descrambled DCI).

[0059] An eavesdropper (such as second UE 120) can decode scrambled DCI 230 after receiving it from BS 130, but the eavesdropper may not be able to descramble the decoded and scrambled DCI 230 because the eavesdropper does not know the PLS key associated with first UE 110. In some embodiments, if CRC 240 is used, the eavesdropper can decode the scrambled DCI 230 because the CRC often passes if there are no errors in the transmission. Therefore, the eavesdropper may decode misleading resource allocations, i.e., resource allocations for interfering resources indicated by scrambled but unscrambled DCI 230. Because BS 130 can send interference messages on interfering resources, the eavesdropper may receive the interference messages. Therefore, if the eavesdropper is, for example, an impostor, the eavesdropper may send feedback (such as HARQ-ACK) in response to the interference message, and BS 130 may identify the presence of the impostor based on the received feedback. In some embodiments, the interference message may include, for example, a transport block (such as a dummy transport block).

[0060] A similar mechanism can also be used for uplink data transmission. In this case, the resources indicated by DCI 210 and scrambled but not descrambled DCI 230 can be uplink shared channels (such as PUSCH resources). After receiving, first UE 110 can decode and descramble the scrambled DCI 230, and then first UE 110 can send data to BS 130 on the resources indicated by DCI 210. In other words, first UE 110 can communicate with BS 130 on the resources indicated by DCI 210 (i.e., the descrambled DCI).

[0061] The first UE 110 may also transmit an interference message on the resources indicated by the scrambled, but not descrambled, DCI 230, because an eavesdropper (such as the second UE 120) may attempt to eavesdrop on the transmission of the first UE 110. The eavesdropper may therefore be busy decoding the interference message, making it more secure to transmit data to the BS 130 on the resources indicated by the DCI 210. That is, the first UE 110 may decode the scrambled DCI 230 to determine that the decoded and scrambled DCI 230 provides valid DCI for the interfering transmission, and then transmit the interference message, i.e., the interfering transmission on the resources indicated by the valid DCI. The first UE 110 may also descramble the decoded and scrambled DCI 230 corresponding to the valid DCI to obtain DCI 210.

[0062] If an eavesdropper (i.e., an imposter) attempts to replace the first UE 110 and the BS 130 and uses interfering resources for transmission (such as PDSCH and PUSCH transmissions) to, for example, schedule HARQ-ACK or send a retransmission request, the BS 130 can identify the imposter or a general threat based on the transmission received on the resources indicated by the scrambled DCI 230 (i.e., the transmission received on the interfering resources). In other words, the BS 130 can identify the threat because there is a transmission on resources that are not allocated to a given UE (e.g., the first UE 110).

[0063] Figure 3 Protection of downlink control information and CRC is shown according to at least some embodiments of the present invention. Figure 3 In, similar to Figure 2 , DCI is represented by 310, the scrambling sequence generated by PLS is represented by 320, the scrambled DCI 310 is represented by 330, and the CRC of the scrambled DCI 330 is represented by 340. In addition, Figure 3 In FIG, the second scrambling sequence is represented by 325 and the scrambled CRC is represented by 350.

[0064] Figure 3 Two-step scrambling is shown, where DCI 310 may first be scrambled using a scrambling sequence generated by PLS 320 to obtain scrambled DCI 330, similar to Figure 2 In the embodiment of the present invention, the DCI 210 may be scrambled using a scrambling sequence generated by the PLS 220 to obtain scrambled DCI 230. In addition, the CRC 340 may be scrambled to obtain a scrambled CRC 350. For example, when calculating the CRC check value or bits for the scrambled DCI 330, the CRC 340 may be scrambled. In some embodiments, the CRC 340 may be scrambled using another second scrambling sequence 325, wherein the second scrambling sequence 325 may not be generated using the PLS. That is, the second scrambling sequence may be different from the PLS key associated with the first UE 110 (i.e., the first scrambling sequence).

[0065] That is, the second scrambling sequence 325 may not be a parameter generated by the PLS, but the second scrambling sequence 325 may be used together with the PLS key to provide BS 130 with additional flexibility in scheduling resource allocation and interference resource allocation (i.e., two transmissions) for UE 110. In addition, the second scrambling sequence 325 may be used to provide additional security. For example, similar to that defined in the 3GPP standard specification, the CRC 340 may be scrambled using the second scrambling sequence 325 based on the radio network temporary identifier (RNTI). In some embodiments, the second scrambling sequence 325 may be known to BS 130 and both UEs (UE 110 and UE 120), or may be known to BS 130 and only UE 110. The second scrambling sequence 325 may be preconfigured, for example, like the RNTI.

[0066] In some embodiments of the present invention, the PLS key associated with UE 110 may correspond to a second scrambling sequence 325. That is, there may be a set of second scrambling sequences 325, and BS 130 may select a sequence 325 from the set of scrambling sequences 325, where the selected scrambling sequence 325 corresponds to the PLS key associated with UE 110. Thus, there may be a one-to-one relationship between the selected second scrambling sequence 325 and the PLS key associated with UE 110, such that both BS 130 and UE 110 may obtain the same understanding of the second scrambling sequence 325 and both may select the same second scrambling sequence 325 based on the PLS key associated with UE 110. If the selected second scrambling sequence does not define a valid DCI for the interfering transmission together with the scrambled DCI 330, BS 130 may change the second scrambling sequence 325 to, for example, another sequence in the set. BS 130 may then check again whether the changed second scrambling sequence together with the scrambled DCI 330 defines a valid DCI for the interfering transmission.

[0067] In some embodiments of the present invention, a CRC check with multiple second scrambling sequences 325 may be applied at the receiver side (e.g., at UE 110) to find a PLS key that matches the used second scrambling sequence 325. Thus, BS 130 may have greater flexibility because there may be multiple options for scrambled DCI 330, which further makes it easier to schedule interfering resources such as PDSCH or PUSCH while transmitting on the resources allocated for UE 110.

[0068] Figure 4An example process according to at least some embodiments of the present invention is shown. For example, the example process may be performed by BS 130 (such as a gNB). At the beginning of the example process, BS 130 may determine that new data can be scheduled for UE 110 (i.e., for downlink data transmission) and, for example, that UE 110 can use PLS. However, if BS 130 determines that new data is to be scheduled for transmission from UE 110 (i.e., for uplink data transmission), the example process may similarly apply.

[0069] Upon determining that new data is available for transmission to UE 110, BS 130 may determine transmission parameters for downlink control channel transmission (such as PDCCH transmission) at step 410. The transmission parameters may include, for example, the DCI format, aggregation level, etc. used for the downlink control channel transmission. At step 420, BS 130 may consider scheduling information (such as PDSCH scheduling information) for downlink data transmission. The scheduling information may include, for example, resource allocations (such as time and frequency resources) for the first UE 110. The scheduling information for downlink data transmission may ultimately determine the exact content of the scrambled or unscrambled DCI to be transmitted.

[0070] At step 430, BS 130 may use the PLS key associated with UE 110 to transmit the DCI of UE 110 (eg, Figure 1 210 in the scrambled DCI). In step 430, BS 130 may also determine whether BS 130 can allocate resources for interference (i.e., interference resources) based on the scrambled DCI. That is, BS 130 may determine whether interference resources can be scheduled based on the scrambled DCI, where the scrambled DCI indicates interference resources if, for example, it is decoded by an eavesdropper (e.g., second UE 120) without being descrambled. BS 130 may determine that the scrambled DCI defines valid downlink control information by identifying the possibility that BS 130 may schedule another transmission (e.g., an interfering transmission).

[0071] For example, BS 130 may determine whether interfering resources may be allocated by checking whether the scrambled DCI of UE 110 indicates or defines valid DCI without descrambling. Valid DCI may, for example, indicate time and frequency resources controlled by BS 130. That is, BS 130 may check the scrambled DCI to determine whether the scrambled DCI (i.e., a scrambled version of at least one possible DCI of first UE 110) defines valid DCI. BS 130 may, for example, check whether the scrambled DCI defines DCI in a correct format (e.g., in a format specified in a 3GPP standard specification).

[0072] If, at step 430, it is determined that the scrambled DCI does not indicate valid DCI, BS 130 may decide not to schedule an interfering transmission based on the scrambled DCI, and the example process may proceed to step 435. At step 435, BS 130 may determine whether a maximum number of attempts has been reached. If the maximum number of attempts has not been reached, the example process may loop back to step 420. However, if, at step 435, it is determined that the maximum number of attempts has been reached, the example process may proceed to step 445.

[0073] At step 445, BS 130 may schedule first UE 110 using resources, and the resources may be determined by the DCI of first UE 110 (eg, Figure 2 210 in the DCI 210), and the PLS key of the first UE 110 may be used (e.g., Figure 2 scrambles the DCI of the first UE 110 using the scrambling sequence 220 in , to generate a scrambled DCI of the first UE 110 (e.g. Figure 2 230 in the scrambled DCI). Thereafter, BS 130 may perform control channel coding and send only the encoded scrambled DCI in a downlink control channel transmission without scheduling any interfering resources.

[0074] On the other hand, if it is determined at step 430 that the scrambled DCI defines a valid DCI (e.g., if decoded by the eavesdropper but not descrambled by the eavesdropper), the example process may proceed to step 440. At step 440, BS 130 may also schedule first UE 110 using resources, which may be indicated by the DCI for first UE 110, and may scramble the DCI for first UE 110 using, for example, a PLS key associated with first UE 110 to generate scrambled DCI for first UE 110. Thereafter, BS 130 may schedule an interfering transmission based on the scrambled DCI for first UE 110. BS 130 may perform control channel coding and transmit in a downlink control channel transmission including the encoded scrambled DCI, wherein the DCI that was scrambled but not descrambled by the eavesdropper indicates a valid DCI (e.g., resources for the interfering transmission).

[0075] That is, in steps 420 to 435, BS 130 may check various possibilities to ensure that it can schedule two transmissions (e.g., PDSCH transmissions), one using scrambled, undescrambled DCI, and another using the actual DCI (i.e., scrambled and then descrambled DCI). Therefore, if step 430 determines that the interfering resource cannot be scheduled, if the process returns to step 430 via steps 435 and 420, another resource, i.e., another DCI, may be allocated to first UE 110. The indication regarding the other DCI may be scrambled using the PLS key associated with first UE 110. BS 130 may then determine whether another valid DCI (i.e., an interfering transmission) can be scheduled based on the scrambled indication regarding the other DCI. If it is determined that the other valid DCI can be scheduled, BS 130 may send the scrambled other DCI. If both transmissions can be scheduled, BS 130 may proceed to the next step, step 440.

[0076] In some embodiments of the present invention, other PLS enhancement functions may be applied in addition to the embodiments described herein.

[0077] Figure 5 An example apparatus capable of supporting at least some embodiments of the present invention is shown. Device 500 is shown, which may include, for example Figure 1 The first UE 110 or BS 130, or the device 500 may be configured to control its functions when it is installed therein. The device 500 includes a processor 510, which may include, for example, a single-core or multi-core processor, wherein a single-core processor includes one processing core and a multi-core processor includes more than one processing core. The processor 510 may generally include a control device. The processor 510 may include more than one processor. The processor 510 may be a control device. The processor 510 may include at least one application-specific integrated circuit (ASIC). The processor 510 may include at least one field-programmable gate array (FPGA). The processor 510 may be a component for executing the method steps in the device 500. The processor 510 may be configured at least in part by computer instructions to perform actions.

[0078] The processor may include circuitry, or be constituted as one or more circuits, configured to perform the stages of the method according to the embodiments described herein. As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) a pure hardware circuit implementation, such as an implementation in analog circuitry and / or digital circuitry only, and (b) a combination of hardware circuitry and software, such as, as applicable: (i) a combination of analog hardware circuitry and / or digital hardware circuitry with software / firmware, and (ii) any portion of a hardware processor with software (including a digital signal processor), software, and memory working together to enable a device (such as a server) to perform various functions, and (c) a hardware circuit and / or processor (such as a microprocessor or a portion of a microprocessor) that requires software (e.g., firmware) for operation, but where the software is not required for operation, the software may not be present.

[0079] This definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers (for example, and if applicable to a particular claim element) a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, cellular network device, or other computing device or network device.

[0080] Device 500 may include memory 520. Memory 520 may include random access memory and / or permanent memory. Memory 520 may include at least one RAM chip. Memory 520 may include, for example, solid-state, magnetic, optical, and / or holographic memory. Memory 520 may be at least partially accessible to processor 510. Memory 520 may be at least partially included in processor 510. Memory 520 may be a component for storing information. Memory 520 may include computer instructions that processor 510 is configured to execute. When computer instructions configured to cause processor 510 to perform certain actions are stored in memory 520, and device 500 as a whole is configured to operate under the direction of processor 510 using the computer instructions from memory 520, processor 510 and / or at least one of its processing cores may be considered to be configured to perform the certain actions. Memory 520 may be at least partially included in processor 510. Memory 520 may be at least partially external to device 500 but accessible to device 500.

[0081] Device 500 may include a transmitter 530. Device 500 may include a receiver 540. Transmitter 530 and receiver 540 may be configured to transmit and receive information, respectively, in accordance with at least one cellular or non-cellular standard. Transmitter 530 may include more than one transmitter. Receiver 540 may include more than one receiver. Transmitter 530 and / or receiver 540 may be configured to operate in accordance with, for example, Global System for Mobile Communications (GSM), Wideband Code Division Multiple Access (WCDMA), 5G / NR, Long Term Evolution (LTE), IS-95, Wireless Local Area Network (WLAN), Ethernet, and / or Worldwide Interoperability for Microwave Access (WiMAX) standards.

[0082] The device 500 may include a near field communication (NFC) transceiver 550. The NFC transceiver 550 may support at least one NFC technology, such as NFC, Bluetooth, Wibree, or similar technology.

[0083] Device 500 may include a user interface UI 560. UI 560 may include at least one of a display, a keyboard, a touch screen, a vibrator arranged to signal a user by vibrating device 500, a speaker, and a microphone. The user may be able to operate device 500 via UI 560, for example, to accept an incoming phone call, initiate a phone call or video call, browse the internet, manage digital files stored in memory 520 or on a cloud accessible via transmitter 530 and receiver 540 or via NFC transceiver 550, and / or play games.

[0084] Device 500 may include or be configured to receive a subscriber identity module 570. Subscriber identity module 570 may include, for example, a subscriber identity module (SIM) card that may be installed in device 500. Subscriber identity module 570 may include information identifying a subscription of a user of device 500. Subscriber identity module 570 may include cryptographic information that may be used to verify the identity of the user of device 500 and / or facilitate encryption of transmitted information and billing of the user of device 500 for communications accomplished through device 500.

[0085] Processor 510 may be configured with a transmitter for outputting information from processor 510 to other devices within device 500 via electrical conductors within device 500. Such a transmitter may include a serial bus transmitter, configured to output information to memory 520 via at least one electrical conductor for storage therein. As an alternative to a serial bus, the transmitter may include a parallel bus transmitter. Similarly, processor 510 may include a receiver, configured to receive information from processor 510 via electrical conductors within device 500 from other devices within device 500. Such a receiver may include a serial bus receiver, configured to receive information from receiver 540 via at least one electrical conductor for processing within processor 510. As an alternative to a serial bus, the receiver may include a parallel bus receiver.

[0086] The device 500 may include Figure 5 Other devices not shown in the figure. For example, if device 500 comprises a smartphone, it may include at least one digital camera. Some devices 500 may include a rear-facing camera and a front-facing camera, where the rear-facing camera may be used for digital photography and the front-facing camera may be used for video calling. Device 500 may include a fingerprint sensor for at least partially authenticating the user of device 500. In some embodiments, device 500 lacks at least one of the aforementioned devices. For example, some devices 500 may lack NFC transceiver 550 and / or user identity module 570.

[0087] The processor 510, memory 520, transmitter 530, receiver 540, NFC transceiver 550, UI 560, and / or user identity module 570 can be interconnected in a variety of different ways via electrical conductors within the device 500. For example, each of the above devices can be individually connected to a main bus within the device 500 to allow the devices to exchange information. However, as will be understood by those skilled in the art, this is merely an example, and various ways of interconnecting at least two of the above devices can be selected according to the embodiment without departing from the scope of the present invention.

[0088] Figure 6 1 is a flow chart of a first method according to at least some embodiments of the present invention. The stages of the illustrated first method may be performed by a base station, such as base station 130, or in a control device configured to control its functions when installed therein. The first method may be used to schedule data transmissions for user equipment and jamming transmissions for eavesdroppers using a single downlink control channel transmission.

[0089] The first method may include, at step 610, determining at least one possible downlink control information for a user equipment to schedule data transmission. The first method may also include, at step 620, checking a scrambled version of the at least one possible downlink control information to determine whether the scrambled version of the at least one possible downlink control information defines valid downlink control information. Additionally, the first method may include, at step 630, sending a scrambled version of the at least one possible downlink control information and scheduling data transmission based on the at least one possible downlink control information. Finally, the first method may include, at step 640, if it is determined that the scrambled version of the at least one possible downlink control information defines valid downlink control information, scheduling an interfering transmission based on the scrambled version of the at least one possible downlink control information.

[0090] Figure 7 is a flow chart of a second method according to at least some embodiments of the present invention.The stages of the second method shown may be performed by a UE such as the first UE 110, or by a control device configured to control its functions, possibly when installed therein.

[0091] The second method may include, at step 710, receiving a scrambled version of at least one downlink control information from a user equipment. The second method may also include, at step 720, decoding the scrambled version of the at least one downlink control information. The first method may include, at step 730, determining that the decoded scrambled version of the at least one downlink control information provides valid downlink control information for the interfering transmission. Additionally, the second method may include, at step 740, transmitting data on resources indicated by the at least one downlink control information. Finally, the second method may include, at step 750, transmitting the interfering transmission on the resources indicated by the valid downlink control information.

[0092] It should be understood that the embodiments disclosed herein are not limited to the specific structures, process steps, or materials disclosed herein, but are extended to equivalents recognized by those skilled in the relevant art. It should also be understood that the terms used herein are only used to describe specific embodiments and are not intended to be limiting.

[0093] Reference throughout this specification to an embodiment or an embodiment means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" throughout this specification are not necessarily all referring to the same embodiment. When terms such as "approximately" or "substantially" are used to refer to values, the exact value is also disclosed.

[0094] As used herein, for convenience, multiple items, structural elements, constituent elements and / or materials may appear in a general list. However, these lists should be interpreted as if each member in the list is individually identified as a separate and unique member. Therefore, in the absence of contrary instructions, any single member in the list should not be interpreted as a de facto equivalent of any other member in the same list simply based on their appearance in a common group. In addition, various embodiments and examples of the present invention may be mentioned here together with alternatives to its various components. It should be understood that such embodiments, examples and alternatives should not be interpreted as de facto equivalents of each other, but should be considered as independent and autonomous representations of the present invention.

[0095] In an exemplary embodiment, an apparatus (eg, the first UE 110 or the BS 130) may include means for performing the above embodiments and any combination thereof.

[0096] In an exemplary embodiment, a computer program may be configured to generate a method according to the above embodiments and any combination thereof. In an exemplary embodiment, a computer program product contained on a non-transitory computer readable medium may be configured to control a processor to perform a process including the above embodiments and any combination thereof.

[0097] In an exemplary embodiment, an apparatus (e.g., a first UE 110 or a BS 130) may include at least one processor and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, using the at least one processor, cause the apparatus to at least perform the foregoing embodiments and any combination thereof.

[0098] In addition, the described features, structures or characteristics can be combined in any suitable manner in one or more embodiments. In the foregoing description, many specific details, such as examples of lengths, widths, shapes, etc., are provided to provide a comprehensive understanding of the embodiments of the present invention. However, those skilled in the relevant art will recognize that the present invention can be implemented without one or more of the specific details, or using other methods, components, materials, etc. In other cases, well-known structures, materials or operations are not shown or described in detail to avoid obscuring various aspects of the present invention.

[0099] Although the above examples illustrate the principles of the present invention in one or more specific applications, it should be understood by those skilled in the art that various modifications may be made to the form, use, and details of implementation without inventiveness and without departing from the principles and concepts of the present invention. Therefore, the present invention is not intended to be limited except as set forth in the claims below.

[0100] The verbs "to comprise" and "to include" are used in this document as open limitations that neither exclude nor require the presence of unrecited features. Features recited in the dependent claims are freely combinable with each other unless expressly stated otherwise. Furthermore, it should be understood that the use of "a" or "an" throughout this document is intended to be singular and does not exclude plural reference.

[0101] Industrial Applicability

[0102] At least some embodiments of the present invention may find industrial application in communication networks where secure transmission over an air interface is required, such as in networks operating according to 3GPP standards.

[0103] List of abbreviations

[0104] 3GPP Third Generation Partnership Project

[0105] BS Base Station

[0106] CRC Cyclic Redundancy Check

[0107] CSI channel status information

[0108] DCI Downlink Control Information

[0109] FDD Frequency Division Duplex

[0110] GSM Global System for Mobile Communications

[0111] IMSI International Mobile Subscriber Identity

[0112] IoT

[0113] LTE Long Term Evolution

[0114] M2M Machine to Machine

[0115] MTC Machine Type Communication

[0116] NFC (Near Field Communication)

[0117] PLS Physical Layer Security

[0118] NR New Radio

[0119] PDCCH Physical Downlink Control Channel

[0120] PDSCH Physical Downlink Shared Channel

[0121] PUSCH Physical Uplink Shared Channel

[0122] RAT Radio Access Technology

[0123] RNTI Radio Network Temporary Identifier

[0124] SIM Subscriber Identity Module

[0125] UE User Equipment

[0126] UI User Interface

[0127] WCDMA Wideband Code Division Multiple Access

[0128] WiMAX Worldwide Interoperability for Microwave Access

[0129] WLAN Wireless Local Area Network

[0130] Reference Signs List

[0131]

[0132]

Claims

1. A method for a base station for scheduling data transmission for a user equipment and interference transmission for an eavesdropper using a single downlink control channel transmission, comprising: - determining at least one downlink control information for the user equipment to schedule the data transmission; - checking a scrambled version of the at least one downlink control information to determine whether the scrambled version of the at least one downlink control information defines valid downlink control information that has not been descrambled; - sending the scrambled version of the at least one downlink control information, and scheduling the data transmission based on the at least one downlink control information; - if it is determined that the scrambled version of the at least one downlink control information defines valid downlink control information, scheduling the interfering transmission based on the scrambled version of the at least one downlink control information; - if it is determined that the scrambled version of the at least one downlink control information does not define valid downlink control information, deciding not to schedule the interfering transmission based on the scrambled version of the at least one downlink control information; as well as -Using a physical layer security key associated with the user equipment to scramble the at least one downlink control information, wherein the physical layer security key is generated based on a transmission channel, an arrival direction or a departure direction, a transmit beam index or a receive beam index, and a path loss between the user equipment and the base station.

2. The method of claim 1 , wherein the scrambled version of the at least one downlink control information indicates at least a resource allocation for the user equipment after descrambling, and the effective downlink control information defined by the scrambled downlink control information includes at least a resource allocation for the interfering transmission.

3. The method according to claim 1 or 2, wherein the valid downlink control information indicates at least time and frequency resources controlled by the base station.

4. The method according to claim 1 or 2, further comprising: - if it is determined that the scrambled version of the at least one downlink control information does not indicate valid downlink control information, allocating further downlink control information for the user equipment; - checking the scrambled version of the further downlink control information to determine whether the scrambled version of the further downlink control information defines further valid downlink control information; as well as - sending the scrambled version of the further downlink control information to the user equipment and scheduling the data transmission based on the further downlink control information.

5. The method according to claim 1 or 2, further comprising: - sending data to the user equipment on the resources indicated by the at least one downlink control information for the user equipment; as well as -Sending an interference message on the resources indicated by the valid downlink control information.

6. The method according to claim 1 or 2, further comprising: - receiving data transmission on resources indicated by the at least one downlink control information for the user equipment; as well as - Identifying a security threat based on a transmission received on the resources indicated by the valid downlink control information.

7. The method according to claim 1 or 2, further comprising: - scrambling the at least one downlink control information using a first scrambling sequence to obtain the scrambled version of the at least one downlink control information; as well as - scrambling cyclic redundancy check bits of the scrambled version of the at least one downlink control information using a second scrambling sequence.

8. The method according to claim 7, further comprising: - selecting the second scrambling sequence from a set of sequences, wherein the set of sequences corresponds to a physical layer security key associated with the user equipment.

9. The method according to claim 7, further comprising: - if the selected second scrambling sequence does not define the valid downlink control information together with the scrambled downlink control information, changing the second scrambling sequence.

10. A method for a user device, comprising: - receiving a scrambled version of at least one downlink control information of a user equipment; - decoding the scrambled version of the at least one downlink control information; - determining that the decoded scrambled version of the at least one downlink control information provides valid downlink control information that is not descrambled for the interfering transmission; - sending data on the resources indicated by the at least one downlink control information; -sending the interfering transmission on the resources indicated by the valid downlink control information; - after said decoding, descrambling said scrambled version of said at least one downlink control information to determine said at least one downlink control information; as well as -Using a physical layer security key associated with the user equipment to descramble the scrambled version of at least one downlink control information of the user equipment, wherein the physical layer security key is generated based on the transmission channel, arrival direction or departure direction, transmission beam index or reception beam index, and path loss between the user equipment and the base station.

11. An apparatus comprising at least one processing core, at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processing core, cause the apparatus to at least perform: - determining at least one downlink control information for a user equipment to schedule data transmission; - checking a scrambled version of the at least one downlink control information to determine whether the scrambled version of the at least one downlink control information defines valid downlink control information that has not been descrambled; - sending the scrambled version of the at least one downlink control information, and scheduling the data transmission based on the at least one downlink control information; - if it is determined that the scrambled version of the at least one downlink control information defines valid downlink control information, scheduling an interfering transmission based on the scrambled version of the at least one downlink control information; - if it is determined that the scrambled version of the at least one downlink control information does not define valid downlink control information, deciding not to schedule the interfering transmission based on the scrambled version of the at least one downlink control information; as well as -Using a physical layer security key associated with the user equipment to scramble the at least one downlink control information, wherein the physical layer security key is generated based on the transmission channel, arrival direction or departure direction, transmission beam index or reception beam index, and path loss between the user equipment and the base station.

12. The apparatus of claim 11, wherein the at least one memory and the computer program code are further configured to, together with the at least one processing core, cause the apparatus to at least perform the method of any one of claims 2 to 9.

13. An apparatus comprising at least one processing core, at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processing core, cause the apparatus to at least perform: - receiving a scrambled version of at least one downlink control information of a user equipment; - decoding the scrambled version of the at least one downlink control information; - determining that the decoded scrambled version of the at least one downlink control information provides valid downlink control information that is not descrambled for the interfering transmission; - sending data on the resources indicated by the at least one downlink control information; -sending the interfering transmission on the resources indicated by the valid downlink control information; - after said decoding, descrambling said scrambled version of said at least one downlink control information to determine said at least one downlink control information; as well as The scrambled version of at least one downlink control information of the user equipment is descrambled using a physical layer security key associated with the user equipment, wherein the physical layer security key is generated based on a transmission channel, an arrival direction or a departure direction, a transmit beam index or a receive beam index, and a path loss between the user equipment and a base station.

14. An apparatus for communication, comprising: - means for determining at least one downlink control information for a user equipment for scheduling data transmission; - means for checking a scrambled version of said at least one downlink control information to determine whether said scrambled version of said at least one downlink control information defines valid downlink control information that has not been descrambled; - means for sending the scrambled version of the at least one downlink control information, and means for scheduling the data transmission based on the at least one downlink control information; - means for scheduling interfering transmissions based on the scrambled version of the at least one downlink control information if it is determined that the scrambled version of the at least one downlink control information defines valid downlink control information; - means for deciding not to schedule the interfering transmission based on the scrambled version of the at least one downlink control information if it is determined that the scrambled version of the at least one downlink control information does not define valid downlink control information; as well as -A component for scrambling the at least one downlink control information using a physical layer security key associated with the user equipment, wherein the physical layer security key is generated based on a transmission channel, an arrival direction or a departure direction, a transmit beam index or a receive beam index, and a path loss between the user equipment and a base station.

15. The apparatus of claim 14, further comprising means for performing the method of any one of claims 2 to 9.

16. An apparatus for communication, comprising: - means for receiving a scrambled version of at least one downlink control information of a user equipment; - means for decoding said scrambled version of said at least one downlink control information; - means for determining that the decoded scrambled version of the at least one downlink control information provides valid downlink control information that is not descrambled for the interfering transmission; - means for sending data on resources indicated by the at least one downlink control information; - means for sending the interfering transmission on resources indicated by the valid downlink control information; - means for descrambling said scrambled version of said at least one downlink control information after said decoding to determine said at least one downlink control information; as well as The scrambled version component is used to descramble the at least one downlink control information of the user equipment using a physical layer security key associated with the user equipment, wherein the physical layer security key is generated based on the transmission channel, arrival direction or departure direction, transmission beam index or reception beam index, and path loss between the user equipment and the base station.

17. A non-transitory computer-readable medium having stored thereon a set of computer-readable instructions, which, when executed by at least one processor, cause an apparatus to at least perform the method according to any one of claims 1 to 9 or 10.

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