Communication method and apparatus

Abstract

A communication method and apparatus, which belong to the technical field of communications. The method comprises: receiving a first reference signal, wherein the first reference signal is used for determining L1 first phases and L2 first amplitudes, and L1 and L2 are positive integers; on the basis of the L1 first phases and the L2 first amplitudes, determining a first channel matrix, wherein the first channel matrix comprises K first elements, the phases of the K first elements are respectively K first phases among the L1 first phases, the amplitudes of the K first elements are respectively K first amplitudes among the L2 first amplitudes, and K is a positive integer less than or equal to L1 and less than or equal to L2; and generating a key on the basis of the first channel matrix. In this way, a first apparatus can re-determine a key generation material. Compared with a solution in which a key is directly generated on the basis of an amplitude and a phase which are estimated by means of a reference signal, the solution can improve the randomness of keys, thereby facilitating an improvement in the security of communications.

Description

Communication method and apparatus

[0001] This application claims priority to the Chinese Patent Application No. 202411340516.0, filed on September 24, 2024, and entitled "Communication method and apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, and more particularly, to a communication method and apparatus. BACKGROUND

[0003] The physical layer key generation technology based on channel entropy can be a technology that both communication parties generate a random key from a channel by using channel reciprocity based on measurement of the physical communication channel. The main steps of the physical layer key generation technology include channel measurement, randomness extraction, channel quantization, information reconciliation, and amplification. Compared with the key generation method based on pseudo-random number generator, the physical layer key generation technology can generate a highly random key stream and support dynamic update, thereby ensuring the freshness of the key. In addition, the physical layer key generation does not need to rely on a root key at a high level, but only needs to generate a key through lightweight channel measurement and negotiation between the two communication parties, greatly reducing the risk of key leakage.

[0004] However, how to improve the randomness of the key is a problem to be solved. SUMMARY

[0005] The present application provides a communication method and apparatus, which can improve the randomness of the key.

[0006] In a first aspect, a communication method is provided. The execution subject of the method provided in the first aspect can be a first apparatus. In the absence of special description, the first apparatus in the present application can be a terminal device or a network device, can also be a component (for example, a processor, a chip, or a chip system, etc.) in the terminal device or the network device, or can also be a logic module or software that can realize all or part of the functions of the terminal device or the network device. For ease of description, the first apparatus is taken as an example for description hereinafter.

[0007] The method comprises: receiving a first reference signal, the first reference signal being used to determine L1 first phases and L2 first amplitudes, L1 and L2 being positive integers; determining a first channel matrix according to the L1 first phases and the L2 first amplitudes, the first channel matrix comprising K first elements, phases of the K first elements being K first phases in the L1 first phases, amplitudes of the K first elements being K first amplitudes in the L2 first amplitudes, K being a positive integer less than or equal to L1 and less than or equal to L2; and generating a key according to the first channel matrix.

[0008] The first device can be an encryption end, for example, the key generated by the first device can be used to encrypt information (e.g., signaling or data) sent by the first device. The first device can also be a decryption end, for example, the key generated by the first device can be used to decrypt information (e.g., signaling or data) received by the first device.

[0009] Based on the above scheme, the first device can determine at least one amplitude (e.g., L2 first amplitudes) and at least one phase (e.g., L1 first phases) according to the reference signal. The first device can select part or all of the above at least one amplitude (e.g., K first amplitudes) and part or all of the above at least one phase (e.g., K first phases), and re-determine the key generation material (e.g., the first channel matrix). Compared with the scheme of directly estimating the amplitude and phase according to the reference signal for key generation, the above scheme can improve the randomness of the key, thereby helping to improve the security of communication.

[0010] In some implementations, the first channel matrix is determined according to the L1 first phases and the L2 first amplitudes, including: determining the first channel matrix according to the first index, the second index, the L1 first phases and the L2 first amplitudes, wherein the first index is the index of the K first phases, and the second index is the index of the K first amplitudes.

[0011] Based on the above scheme, the first device can filter out K first amplitudes and K first phases from L1 first amplitudes and L1 first phases according to the first index and the second index, respectively, which has less processing overhead.

[0012] In some implementations, the first index is the index of the K second phases, and the positions of the K second phases in the L1 second phases are the same as the positions of the K first phases in the L1 first phases; wherein the average up-down line difference of the K second phases is less than or equal to a first threshold value, and / or the average correlation coefficient of the K second phases is less than or equal to a second threshold value, the average up-down line difference of the K second phases is determined according to the K second phases and K third phases in the L1 third phases, and the positions of the K third phases in the L1 third phases are the same as the positions of the K first phases in the L1 first phases; wherein the K second phases are determined according to an uplink reference signal, and the K third phases are determined according to a downlink reference signal, or the K second phases are determined according to a downlink reference signal, and the K third phases are determined according to an uplink reference signal.

[0013] Based on the above scheme, the second phase corresponding to the first index satisfies the requirement of low correlation and good reciprocity. Therefore, the K first phases corresponding to the first index are likely to satisfy the requirement of low correlation and good reciprocity. The above scheme can improve the quality of the K first phases used to generate the key, thereby further improving the randomness and consistency of the key.

[0014] In some implementations, the second index is an index of K second amplitudes, positions of the K second amplitudes in L2 second amplitudes are same as positions of the K first amplitudes in the L2 first amplitudes; wherein, an average up-down difference of the K second amplitudes is less than or equal to a third threshold value, and / or, an average correlation coefficient of the K second amplitudes is less than or equal to a fourth threshold value, the average up-down difference of the K second amplitudes is determined according to the K second amplitudes and K third amplitudes in L2 third amplitudes, positions of the K third amplitudes in the L2 third amplitudes are same as positions of the K first amplitudes in the L2 first amplitudes; wherein, the K second amplitudes are determined according to an uplink reference signal, the K third amplitudes are determined according to a downlink reference signal, or, the K second amplitudes are determined according to the downlink reference signal, the K third amplitudes are determined according to the uplink reference signal.

[0015] Based on the above scheme, the second amplitude corresponding to the second index satisfies the requirement of low correlation and good reciprocity. Therefore, the K first amplitudes corresponding to the second index are likely to satisfy the requirement of low correlation and good reciprocity. The above scheme can improve the quality of the K first amplitudes used to generate the key, thereby further improving the randomness and consistency of the key.

[0016] In some implementations, according to the first channel matrix, the key is generated, including: determining a second channel matrix according to the first channel matrix, the second channel matrix including K second elements, phases of the K second elements being a sum of the K first phases and a first parameter; generating the key according to the second channel matrix.

[0017] Based on the above scheme, the first device can add the first parameter to the K first phases to obtain the phases of the K second elements. The phases of the second elements can be uniformly distributed in a larger range, thereby improving the rate of key generation. In addition, the above scheme can not increase the up-down difference of the phases of the second elements, thereby guaranteeing the consistency of the generated key.

[0018] In some implementations, the first parameter is predefined or preconfigured; or the method further includes: receiving or sending first information, the first information being used to indicate the first parameter.

[0019] Based on the above scheme, the first parameter can be a parameter known by the two parties of communication (e.g., the first device and the second device), so that the two parties of communication can use the same parameter to determine the key generation material (e.g., the second channel matrix), thereby improving the consistency of the key.

[0020] In some implementations, the initial phase of the first reference signal is determined according to the second parameter, and / or the method further includes: transmitting a second reference signal, an initial phase of the second reference signal being determined according to the first parameter.

[0021] Based on the above scheme, the initial phase of the first reference signal can be determined according to the second parameter. In this way, the first device can add the K first phases (carrying the second parameter) determined by the first reference signal to the first parameter, so as to jointly determine the phase for generating the key with the opposite end (e.g., the second device) of the first device. The initial phase of the second reference signal transmitted by the first device can be determined according to the first parameter. In this way, the opposite end of the first device can add the phase (carrying the first parameter) determined by the second reference signal to the second parameter, so as to jointly determine the phase for generating the key with the first device. In the above scheme, the first device and the opposite end of the first device determine the parameters without plaintext interaction, so that the phase for generating the key is uniformly distributed in a larger range. Therefore, the above scheme can improve the rate of key generation while ensuring security.

[0022] In some implementations, the key is determined according to a third parameter and a quantization threshold, where the third parameter is a spectral norm of the first channel matrix or a spectral norm of the second channel matrix, the second channel matrix including K second elements, phases of the K second elements being a sum of the L1 first phases and the first parameter; and the quantization threshold is determined according to K.

[0023] Based on the above scheme, the quantization threshold can be determined according to K. In this case, the larger the value of K is, the higher the consistency of the key is. Therefore, by using the above quantization threshold, the consistency of the key can be controlled by the value of K.

[0024] In some implementations, the quantization threshold is 2σ e K 1 / 4 , where σ eThe maximum standard deviation of the average uplink-downlink difference of the K first elements or the maximum standard deviation of the average uplink-downlink difference of the K second elements, phases of the K second elements being a sum of the L1 first phases and the first parameter, wherein the average uplink-downlink difference of the K first elements is determined according to K second phases, K third phases, K second amplitudes and K third amplitudes, the average uplink-downlink difference of the K second elements is determined according to the K second phases, the K third phases, the K second amplitudes, the K third amplitudes and the first parameter; wherein the K second phases are determined according to the uplink reference signal, the K third phases are determined according to the downlink reference signal, or the K second phases are determined according to the downlink reference signal, the K third phases are determined according to the uplink reference signal; wherein the K second amplitudes are determined according to the uplink reference signal, the K third amplitudes are determined according to the downlink reference signal, or the K second amplitudes are determined according to the downlink reference signal, the K third amplitudes are determined according to the uplink reference signal.

[0025] Based on the above-mentioned quantization threshold, the consistency of the key can be further improved.

[0026] In some implementations, the L1 first phases include L1' fourth phases and L1'' fifth phases, L1' and L1'' are positive integers less than L1, one of the L1' fourth phases is a difference between a receiving initial phase of the first antenna and a receiving initial phase of the second antenna, wherein the key is used to encrypt information sent through the first antenna, the key is used to encrypt information sent through the second antenna; or, one of the L1'' fifth phases is a difference between a sending initial phase of the first antenna and a sending initial phase of the second antenna, wherein the key is used to decrypt information sent through the first antenna, the key is used to decrypt information sent through the second antenna.

[0027] Based on the above scheme, the first antenna and the second antenna can be two antennas corresponding to the same device, and thus the L1 fourth phases can be differences between receiving initial phases of the two antennas corresponding to the same device; the L1'' fifth phases can be differences between sending initial phases of the two antennas corresponding to the same device. Those skilled in the art can understand that the antennas corresponding to the same device often use the same clock. Even if the initial phase (for example, the sending initial phase or the receiving initial phase) of one antenna drifts, since the initial phase of the other antenna also drifts, the difference between the initial phases of the two antennas corresponding to the same device is relatively stable. Therefore, the first phase based on which the first device generates the key is relatively stable. Compared with the scheme of generating the key directly based on the initial phase, the above scheme is less affected by the phase drift of the two communication parties. Therefore, the above scheme can further improve the consistency of the key.

[0028] In a second aspect, a communication device is provided, which includes a processing circuit (or processor) and an input-output interface (which can also be referred to as an interface circuit) for inputting and / or outputting signals, and the processing circuit is configured to perform the first aspect and any possible method of the first aspect.

[0029] In some implementations, the processing circuit is configured to communicate with other devices through the interface circuit, and perform the first aspect and any possible method of the first aspect.

[0030] In a third aspect, a communication device is provided. The communication device can include units or modules for performing the functions of the communication device.

[0031] In some implementations, the communication device can include modules or units or means corresponding to the methods / operations / steps / actions described in the first aspect and any possible implementation of the first aspect, which can be hardware circuits, software, or a combination of hardware circuits and software.

[0032] The device includes a processing unit and a transceiver unit. The transceiver unit is configured to receive a first reference signal, the first reference signal being used to determine L1 first phases and L2 first amplitudes, L1 and L2 being positive integers; the processing unit is configured to determine a first channel matrix according to the L1 first phases and the L2 first amplitudes, the first channel matrix including K first elements, phases of the K first elements being K first phases of the L1 first phases, and amplitudes of the K first elements being K first amplitudes of the L2 first amplitudes, K being a positive integer less than or equal to L1 and less than or equal to L2; and the processing unit is further configured to generate a key according to the first channel matrix.

[0033] In some embodiments, the processing unit is specifically configured to determine the first channel matrix according to the first index, the second index, the L1 first phases and the L2 first amplitudes, wherein the first index is an index of the K first phases, and the second index is an index of the K first amplitudes.

[0034] In some embodiments, the first index is an index of K second phases, and positions of the K second phases in the L1 second phases are same as positions of the K first phases in the L1 first phases; wherein an average up-down difference of the K second phases is less than or equal to a first threshold value, and / or an average correlation coefficient of the K second phases is less than or equal to a second threshold value, and the average up-down difference of the K second phases is determined according to the K second phases and K third phases in L1 third phases, and positions of the K third phases in the L1 third phases are same as positions of the K first phases in the L1 first phases; wherein the K second phases are determined according to an uplink reference signal, and the K third phases are determined according to a downlink reference signal, or the K second phases are determined according to a downlink reference signal, and the K third phases are determined according to an uplink reference signal.

[0035] In some embodiments, the second index is an index of K second amplitudes, and positions of the K second amplitudes in the L2 second amplitudes are same as positions of the K first amplitudes in the L2 first amplitudes; wherein an average up-down difference of the K second amplitudes is less than or equal to a third threshold value, and / or an average correlation coefficient of the K second amplitudes is less than or equal to a fourth threshold value, and the average up-down difference of the K second amplitudes is determined according to the K second amplitudes and K third amplitudes in L2 third amplitudes, and positions of the K third amplitudes in the L2 third amplitudes are same as positions of the K first amplitudes in the L2 first amplitudes; wherein the K second amplitudes are determined according to an uplink reference signal, and the K third amplitudes are determined according to a downlink reference signal, or the K second amplitudes are determined according to a downlink reference signal, and the K third amplitudes are determined according to an uplink reference signal.

[0036] In some embodiments, the processing unit is specifically configured to determine a second channel matrix according to the first channel matrix, and the second channel matrix comprises K second elements, and phases of the K second elements are a sum of the K first phases and a first parameter; and generate the key according to the second channel matrix.

[0037] In some embodiments, the first parameter is predefined or preconfigured; or the transceiver is further configured to receive or transmit first information, and the first information is used to indicate the first parameter.

[0038] In some embodiments, the initial phase of the first reference signal is determined according to a second parameter, and / or the transceiver is further configured to: transmit a second reference signal, an initial phase of the second reference signal being determined according to the first parameter.

[0039] In some embodiments, the key is determined according to a third parameter and a quantization threshold, wherein the third parameter is a spectral norm of the first channel matrix or a spectral norm of a second channel matrix, the second channel matrix comprising K second elements, phases of the K second elements being a sum of the L1 first phases and the first parameter; wherein the quantization threshold is determined according to K.

[0040] In some embodiments, the quantization threshold is 2σ e K 1 / 4 , wherein σ e is a maximum standard deviation of an average up-down difference of the K first elements or a maximum standard deviation of an average up-down difference of K second elements, phases of the K second elements being a sum of the L1 first phases and the first parameter, wherein the average up-down difference of the K first elements is determined according to K second phases, K third phases, K second amplitudes, and K third amplitudes, the average up-down difference of the K second elements is determined according to the K second phases, the K third phases, the K second amplitudes, the K third amplitudes, and the first parameter; wherein the K second phases are determined according to an uplink reference signal, the K third phases are determined according to a downlink reference signal, or the K second phases are determined according to the downlink reference signal, the K third phases are determined according to the uplink reference signal; wherein the K second amplitudes are determined according to the uplink reference signal, the K third amplitudes are determined according to the downlink reference signal, or the K second amplitudes are determined according to the downlink reference signal, the K third amplitudes are determined according to the uplink reference signal.

[0041] In some embodiments, the L1 first phases comprise L1’ fourth phases and L1” fifth phases, L1’ and L1” being positive integers less than L1, one of the L1’ fourth phases being a difference between a receive initial phase of a first antenna and a receive initial phase of a second antenna, wherein the key is used to encrypt information transmitted through the first antenna, the key is used to encrypt information transmitted through the second antenna; or one of the L1” fifth phases being a difference between a transmit initial phase of the first antenna and a transmit initial phase of the second antenna, wherein the key is used to decrypt information transmitted through the first antenna, the key is used to decrypt information transmitted through the second antenna.

[0042] In a fourth aspect, a computer readable storage medium is provided, having stored thereon a computer program or instructions, which when executed by a processor, cause any of the methods of the first aspect to be performed (or implemented).

[0043] In a fifth aspect, a computer program product is provided, comprising a computer program or instructions, which when executed by a processor, cause any of the methods of the first aspect to be performed (or implemented).

[0044] In a sixth aspect, a communication apparatus is provided, comprising a processor configured to cause any of the methods of the first aspect to be performed (or implemented) by executing computer program (or computer executable instructions) stored in the memory and / or by logic circuitry.

[0045] In a possible implementation, the apparatus further comprises a memory. In a possible implementation, the processor and the memory are integrated together. In another possible implementation, the memory is located outside the communication apparatus. The processor can comprise one or more processors.

[0046] In a possible implementation, the communication apparatus further comprises a communication interface configured to enable the communication apparatus to communicate with other devices, such as transmitting or receiving data and / or signals. Exemplarily, the communication interface can be a transceiver, a circuit, a bus, a module or other types of communication interface.

[0047] In an implementation form, the communication apparatus of the second aspect, the third aspect or the sixth aspect can be a chip or a chip system.

[0048] In a seventh aspect, a chip is provided, comprising a processor configured to invoke computer program or computer instructions in a memory to cause any of the implementation forms of the first aspect to be performed (or implemented).

[0049] In some implementation forms, the processor is coupled to the memory via an interface.

[0050] The description of the beneficial effects of any of the second aspect to the seventh aspect can refer to the description of the beneficial effects of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0051] FIG. 1 is a schematic diagram of a communication system.

[0052] FIG. 2 is a schematic diagram of another communication system.

[0053] FIG. 3 is a schematic flowchart of a communication method according to an embodiment of the present application.

[0054] FIG. 4 is a schematic diagram of channel estimation in a multi-antenna system according to an embodiment of the present application.

[0055] FIG. 5 is a schematic diagram of antenna combination and channel combination according to an embodiment of the present application.

[0056] FIG. 6 is a schematic diagram of distribution of K first phases according to an embodiment of the present application.

[0057] FIG. 7 is a schematic diagram of double-threshold quantization according to an embodiment of the present application.

[0058] FIG. 8 is a schematic flowchart of another communication method according to an embodiment of the present application.

[0059] FIG. 9 is a schematic block diagram of a communication apparatus according to an embodiment of the present application.

[0060] FIG. 10 is a schematic block diagram of another communication apparatus according to an embodiment of the present application.

[0061] FIG. 11 is a schematic block diagram of still another communication apparatus according to an embodiment of the present application.

[0062] FIG. 12 is a schematic block diagram of still another communication apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0063] In the present application, the terms and / or descriptions in different embodiments are consistent and can be referred to each other if there is no special description and logical conflict, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0064] In the present application, "at least one" means one or more, and "multiple" means two or more. "And / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the following cases: A exists alone, A and B exist together, B exists alone, where A and B can be singular or plural. In the literal description of the present application, the character " / " generally represents that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions means any combination of these items, including any combination of single item or multiple items. For example, at least one of a, b and c can represent: a, or b, or c, or a and b, or a and c, or b and c, or a, b and c. Where a, b and c can be single or multiple.

[0065] In the present application, "first", "second", and various numerical numbers (e.g., #1, #2, etc.) indicate the differentiation for the convenience of description, and are not used to limit the scope of the embodiments of the present application. For example, different messages are differentiated, rather than used to describe a specific order or sequence. It should be understood that the objects thus described can be interchanged under appropriate circumstances, so as to be able to describe solutions other than the embodiments of the present application.

[0066] In the present application, "when", "in the case of", and "if" and the like descriptions all refer to the objective situation in which the device will make corresponding processing, and are not limited in time, and do not require the device to have a judgment action when implemented, nor does it mean that there are other limitations.

[0067] In the present application, "indicate" or "for indicating" can include direct indication and indirect indication. When describing that certain indication information is used to indicate A, it can include that the indication information directly indicates A or indirectly indicates A, and it does not mean that A must be carried in the indication information.

[0068] The indication manner involved in the embodiments of the present application should be understood as covering various methods that can enable the to-be-indicated party to know the to-be-indicated information. The to-be-indicated information can be sent as a whole, or can be sent separately into multiple sub-information, and the sending period and / or sending time of these sub-information can be the same or different, and the present application does not limit the sending method.

[0069] The "indication information" in the embodiments of the present application can be explicit indication, that is, directly indicated through signaling, or obtained according to the parameters indicated by the signaling, combined with other rules or combined with other parameters or through derivation. It can also be implicit indication, that is, obtained according to rules or relationships, or according to other parameters, or through derivation. The present application does not make specific limitations on this.

[0070] In the present application, "protocol" can refer to a standard protocol in the communication field, which can include 5G protocol, new radio (NR) protocol, and related protocols applied in future communication systems, and the present application does not limit this. "Predefined" can include predefinition. For example, protocol definition. "Preconfigured" can be implemented by pre-storing corresponding codes, tables or other methods that can be used to indicate related information in the device, and the present application does not limit the implementation manner.

[0071] In this application, “communication” can also be described as “data transmission”, “information transmission”, “data processing” and the like. “Transmission” includes “sending” and “receiving”. Exemplarily, the transmission can be uplink transmission, for example, the terminal device can send a signal to the network device; the transmission can also be downlink transmission, for example, the network device can send a signal to the terminal device; the transmission can also be sidelink transmission, for example, the terminal device can send a signal to another terminal device. Exemplarily, “transmission” can be air interface level transmission, or can be signal sending at chip input (I) / output (O) port, rather than air interface level transmission.

[0072] In this application, “message”, “information”, “signal” or “information element (IE)” and the like can be used interchangeably, and the name of the message or information is not limited in any way, as long as the corresponding function can be implemented.

[0073] “Sending information to XX (device)” can be understood as that the destination of the information is the device. It can include directly or indirectly sending information to the device. “Receiving information from XX (device), or receiving information from XX (device)” can be understood as that the source of the information is the device, and it can include directly or indirectly receiving information from the device. The information can be processed as necessary between the source and the destination of the information sending, for example, format change and the like, but the destination can understand the valid information from the source. Similar expressions in this application can be understood similarly, and will not be described here. In addition, “sending” can also be understood as “output” of the chip interface, and “receiving” can also be understood as “input” of the chip interface. In other words, “sending” or “receiving” can be performed between devices, for example, the network device and the terminal device send or receive through the air interface respectively, and “sending” or “receiving” can also be performed within the device, for example, through a bus, a wire or an interface to send or receive between components, modules, chips, software modules or hardware modules within the device.

[0074] In this application, words such as “exemplarily” and “for example” are used to represent examples, illustrations or descriptions, and to present concepts in a specific way. Any embodiment or design scheme described as “example” in this application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. In the embodiments of this application, “of”, “corresponding”, “corresponding” and “associated” can be used interchangeably at times, and it should be pointed out that when the distinction is not emphasized, the meanings expressed are consistent.

[0075] In this application, the configuration can be signaling configuration, or can be described as configuration signaling. For example, the signaling configuration includes configuration by signaling sent by a network device, which can be a radio resource control (RRC) message, downlink control information (DCI), or a system information block (SIB). For another example, the signaling configuration includes configuration between network devices. Wherein, the network device can include an access network device, a core network device, or a management plane device, etc. Optionally, the signaling configuration can also be configured to a terminal device or a network device by pre-configuration, or configured to a terminal device or a network device by pre-configuration. Here, the pre-configuration is to define or configure the value of the corresponding parameter in advance in the protocol, and store it in the terminal device or the network device when communicating with the terminal device or the network device. The pre-configured message can be modified or updated under the condition that the terminal device or the network device is connected to the network.

[0076] The present application will present various aspects, embodiments or features around a system that can include a plurality of devices, components, modules, etc. Each system can include devices, components, modules, etc. other than the illustrated devices, components, modules, etc. and / or can not include all of the devices, components, modules, etc. discussed in conjunction with the figures.

[0077] The service scenarios described in the embodiments of the present application are used to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems as new service scenarios appear.

[0078] In various embodiments of the present application, the size of the serial number of each process does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The terms "include", "contain", "have" and their variants mean "include but not limited to", unless otherwise specifically emphasized.

[0079] The technical solutions of the embodiments of the present application can be applied to various communication systems, including but not limited to: long term evolution (LTE) system, new radio (NR) system, etc. fifth generation (5G) communication system, etc. thA mobile communication system can include a 5th-Generation (5G) mobile communication system, a narrow band internet of things (NB-IoT) system, an enhanced machine-type communication (eMTC) system, an enhanced mobile broadband (eMBB) system, an ultra reliable low latency communications (URLLC) system, a satellite communication system, an LTE-machine-to-machine (LTE-M) system, or a system evolved from the 5G system, such as a future mobile communication system.

[0080] FIG. 1 is a schematic diagram of a communication system 100. As shown in FIG. 1, the communication system 100 includes a radio access network 110 and a core network 120. Optionally, the communication system 100 can further include an Internet 130. The radio access network 110 can include at least one network device (e.g., 111a and 111b in FIG. 1) and at least one terminal device (e.g., 112a-112j in FIG. 1). The terminal device is connected to the network device in a wireless manner. The network device is connected to the core network 120 in a wireless or wired manner. The core network 120 can include one or more core network devices. The core network device and the network device can be independent and different physical devices, or the functions of the core network device and the logical functions of the network device can be integrated into the same physical device, or a physical device can integrate the functions of part of the core network device and part of the network device. The terminal device and the terminal device, and the network device and the network device can be connected to each other in a wired or wireless manner. The terminal device and the terminal device, the network device and the network device, and the terminal device and the network device can communicate with each other in a wireless manner through air interface resources. Exemplarily, the air interface resources can include at least one of time domain resources, frequency domain resources, code resources, and space resources. It should be noted that FIG. 1 is only a schematic diagram, and the communication system 100 can further include other network devices, such as a wireless relay device and a wireless backhaul device, which are not shown in FIG. 1.

[0081] The network device can be any device with wireless transceiver function, for example, the network device can be a base station for accessing terminal devices to a radio access network (RAN). The network device can also be referred to as an access network device or an access network node. It can be understood that in systems using different wireless access technologies, the names of devices with network device functions can be different. For convenience of description, the apparatuses providing wireless communication access functions for terminal devices in the embodiments of the present application are collectively referred to as base stations. In the embodiments of the present application, the network device includes but is not limited to various forms of macro base stations (such as 111a in FIG. 1), micro base stations or indoor stations (such as 111b in FIG. 1), pico base stations, small stations, balloon stations, relay stations, access points, etc. The network device can include evolved node B (eNB or eNodeB) in LTE, access point (AP) in wireless fidelity (WiFi) system, wireless relay node, wireless backhaul node, transmission point (TP) or transmission reception point (TRP), etc. It can also include next generation NodeB (gNB) or transmission point (TRP or TP) in 5G system, one or a group of (including multiple antenna panels) antenna panels of a base station in 5G system, network nodes constituting a gNB or a transmission point, such as a baseband unit (BBU) or a distributed unit (DU), and can also include network devices, servers or vehicle-mounted devices, etc. in networks evolved after 5G. The network device can also be a module or unit that completes part of the function of the base station, for example, it can be a central unit (CU) or a DU.

[0082] In the embodiments of the present application, the apparatus for implementing the function of the network device can be a network device, or an apparatus capable of supporting the network device to implement the function, such as a chip system, which can be installed in the network device. The chip system can be composed of a chip, or can include a chip and other discrete devices.

[0083] In another possible scenario, a plurality of network devices cooperates to assist a terminal to implement wireless access, and different network devices respectively implement part of functions of a base station. For example, a network device can be a CU, a DU, a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. The CU and the DU can be separately arranged, or can be included in the same network element, for example, in a BBU. The RU can be included in a radio frequency device or a radio frequency unit, for example, in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0084] In different systems, the CU (or CU-CP and CU-UP), the DU, or the RU can also have different names, but those skilled in the art can understand their meanings. For example, in an open radio access network (O-RAN) system, the CU can also be referred to as an O-CU (open CU), the DU can also be referred to as an O-DU, the CU-CP can also be referred to as an O-CU-CP, the CU-UP can also be referred to as an O-CU-UP, and the RU can also be referred to as an O-RU. For the convenience of description, the CU, the CU-CP, the CU-UP, the DU, and the RU are taken as examples for description in this application. Any one of the CU (or the CU-CP, the CU-UP), the DU, and the RU in this application can be implemented by means of a software module, a hardware module, or a combination of a software module and a hardware module. The embodiments of this application do not limit the specific technology and the specific device form adopted by the network device.

[0085] The terminal device can be a device providing voice and / or data connectivity to users; the terminal device can also be a device having wireless connection function. The terminal device can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; can also be deployed on water surface (such as ships, etc.); can also be deployed in the air (such as airplanes, balloons and satellites, etc.). The terminal device can also be referred to as user equipment (UE), access terminal, terminal, subscriber unit, subscriber station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, wireless network device, user agent or user apparatus. In the embodiments of the present application, the terminal device includes but is not limited to: cellular phone, mobile phone, wireless data card, wireless modem, pad, laptop computer, notebook computer, palm computer, mobile internet device (MID), computer with wireless transceiver function, cordless phone, session initiation protocol (SIP) phone, smart phone, wireless local loop (WLL) station, personal digital assistant (PDA), handset with wireless communication function, computing device or other device connected to wireless modem, vehicle-mounted device (such as automobile, bicycle, electric vehicle, airplane, ship, train, high-speed rail, etc.), wearable device (such as smart watch, smart bracelet, pedometer, smart glasses, etc.), satellite terminal, terminal device in Internet of Things or Internet of Vehicles, and any form of terminal in future network, relay user equipment or terminal in future evolved public land mobile network (PLMN), etc.The terminal device can also be a virtual reality (VR) device, an augmented reality (AR) device, a smart point of sale (POS) machine, a customer-premises equipment (CPE), a light UE, a reduced capability UE (REDCAP UE), a machine type communication (MTC) terminal, a terminal device in industrial control, a terminal device in self driving, a terminal device in telemedicine, a terminal device in smart grid, a wireless terminal in transportation safety, a terminal device in smart city, a terminal device in smart home, a haptic terminal device, a smart home device (e.g., a refrigerator, a television, an air conditioner, an electricity meter, etc.), a smart robot, a mechanical arm, a plant device, a wireless terminal in self driving, or a flight device (e.g., a smart robot, a hot air balloon, a drone, an airplane), etc. The terminal device can also be a vehicle device, such as a whole vehicle device, a vehicle-mounted module, a vehicle-mounted chip, an on board unit (OBU), or a telematics box (T-BOX), etc. The terminal device can also be other devices with terminal functions, for example, the terminal device can also be a device in device to device (D2D) communication. The embodiments of the present application are not limited in this regard.

[0086] In the embodiments of the present application, the device for implementing the function of the terminal device can be a terminal device, or a device capable of supporting the terminal device to implement the function, such as a chip or a chip system, which can be installed in the terminal device. The chip system can be composed of a chip, or can include a chip and other discrete devices. In the technical solutions of the embodiments of the present application, the device for implementing the function of the terminal device is a terminal device, which can also be referred to as a terminal. In the following description, the terminal device can be taken as an example of a UE.

[0087] The roles of the base station and the terminal can be relative, for example, the helicopter or the drone 112i in FIG. 1 can be configured as a mobile base station, and for those terminals 112j accessing the wireless access network 110 through 112i, the terminal 112i is a base station; but for the base station 111a, 112i is a terminal, that is, 111a and 112i communicate through a wireless air interface protocol. Of course, 111a and 112i can also communicate through a base station-to-base station interface protocol, in which case 112i is also a base station relative to 111a. Therefore, the base station and the terminal can be collectively referred to as a communication device, and 111a and 111b in FIG. 1 can be referred to as a communication device with a base station function, and 112a-112j in FIG. 1 can be referred to as a communication device with a terminal function.

[0088] The network device and the terminal device can communicate through a wireless link. The transmission link from the network device to the terminal device can be referred to as a downlink (DL) or a downlink channel, for transmitting a downlink signal. The transmission link from the terminal device to the network device can be referred to as an uplink (UL) or an uplink channel, for transmitting an uplink signal. The transmission link from one terminal device to another terminal device can be referred to as a sidelink (SL) or a sidelink channel, for transmitting a sidelink signal.

[0089] FIG. 2 is a schematic diagram of another communication system. Referring to FIG. 2, the network device can communicate with one or more terminal devices.

[0090] An exemplary application scenario is that a third-party user can send a request message to the network device, which can be used to request data interaction with the terminal device. The network device and the terminal device can respectively generate a physical layer key. The generated physical layer key can be used to protect the transmission of the data of the third-party user between the network device and the terminal device. The generated physical layer key can also be used to protect the transmission of signaling information between the network device and the terminal device. For example, the third-party user can be an application server, another terminal, or other users.

[0091] The mainstream physical layer key generation technology can generate a key according to the amplitude of the channel. The amplitude of the channel can be the channel strength when the electromagnetic signal reaches the receiver, which has strong reciprocity. However, in a static scenario, the amplitude of the channel is relatively stable, and the key generated based on the amplitude often has the characteristic of poor randomness.

[0092] Therefore, how to improve the randomness of the key is a technical problem to be solved.

[0093] FIG. 3 is a schematic flowchart of a communication method 300 according to an embodiment of the present application. The method 300 can improve the randomness of a key. Optional operations in the method 300 are shown in dashed lines in FIG. 3. The method 300 is described by way of example with respect to the interaction between a first device and a second device. The first device and the second device in the method 300 are described first.

[0094] Unless specifically stated, the first device in the method of the present application can be a terminal device or a network device, or can be a component (e.g., a processor, a chip, or a chip system, etc.) in a terminal device or a network device, or can be a logical module or software, etc. capable of implementing all or part of the functions of a terminal device or a network device.

[0095] Unless specifically stated, the second device in the method of the present application can be a terminal device or a network device, or can be a component (e.g., a processor, a chip, or a chip system, etc.) in a terminal device or a network device, or can be a logical module or software, etc. capable of implementing all or part of the functions of a terminal device or a network device.

[0096] The specific examples of the first device and the second device are described below, which are referred to as scenario example 1 to scenario example 4. For ease of description, the first device is taken as a terminal device or a network device, and the second device is taken as a terminal device or a network device in the following description.

[0097] In scenario example 1, the first device can be a terminal device, and the second device can be a network device.

[0098] In scenario example 2, the first device can be a network device, and the second device can be a terminal device.

[0099] In scenario example 3, the first device can be a network device, and the second device can be another network device.

[0100] In scenario example 4, the first device can be a terminal device, and the second device can be another terminal device.

[0101] The operations in the method 300 are described below with respect to the interaction between the first device and the second device, in combination with FIG. 3.

[0102] In S310, the first device receives a first reference signal from the second device, the first reference signal being used to determine L1 first phases and L2 first amplitudes, L1 and L2 being positive integers. Correspondingly, the second device sends the first reference signal to the first device.

[0103] The first reference signal can be a reference signal (RS). The first reference signal can be information known to the first device and the second device. The first reference signal can reflect characteristics of a channel between the first device and the second device.

[0104] The present application does not limit the specific form of the first reference signal. Illustratively, in scenario example 1, the first reference signal can be a downlink reference signal, for example, a channel state information (CSI)-RS. In scenario example 2, the first reference signal can be an uplink reference signal, for example, a sounding reference signal (SRS).

[0105] In some possible implementations, the method 300 further includes: determining, by the first device, L1 first phases and L2 first amplitudes according to the first reference signal. For example, the first device can perform channel estimation according to the first reference signal to determine L1 first phases and L2 first amplitudes. The L1 first phases and the L2 first amplitudes can reflect characteristics of a channel from the second device to the first device.

[0106] S320, determining, by the first device, a first channel matrix according to the L1 first phases and the L2 first amplitudes.

[0107] The first channel matrix includes K first elements, phases of the K first elements are K first phases of the L1 first phases, amplitudes of the K first elements are K first amplitudes of the L2 first amplitudes, and K is a positive integer less than or equal to L1 and less than or equal to L2.

[0108] Illustratively, taking one first element in the first channel matrix as an example, the first element can be in the form of a complex exponential function, for example, |h|e jθ The first amplitude can be an amplitude h of the first element, and the first phase can be a phase θ of the first element. Wherein, j can represent an imaginary number.

[0109] The above S320 can also be understood as: selecting, by the first device, K first phases from the L1 first phases and K first amplitudes from the L2 first amplitudes, and recombining one first phase of the K first phases and one first amplitude of the K first amplitudes into one first element. Further, the first device can recombine the K first phases and the K first amplitudes into K first elements. Further, the first device can combine the K first elements into the first channel matrix.

[0110] In some examples, the L1 first phases and the L2 first magnitudes can be magnitudes and phases of elements in a channel matrix (denoted as H) estimated by the first device. In some possible implementations, the positions of the K first phases in the L1 first phases are different from the positions of the K first magnitudes in the L2 first magnitudes. For example, the phase of an element 1 in the K first elements can be the phase of an element 2 in the H; the magnitude of the element 1 can be the magnitude of an element 3 (different from the element 2) in the H. In other words, the phase and the magnitude of at least one element in the K first elements can be from different elements in the H.

[0111] The above examples are merely for the convenience of understanding and do not limit the actual generation of the first channel matrix by the first device.

[0112] At S330, the first device generates a key according to the first channel matrix.

[0113] For example, the first device can generate the key according to the first channel matrix as key generation material and a physical layer key generation algorithm.

[0114] The key can be used to encrypt information sent by the first device to the second device. The key can be used to decrypt information received by the first device from the second device. The above-mentioned "information" that is sent or received can be data and / or signaling, which is not limited in the present application. The signaling can be underlying signaling (for example, physical layer signaling) or other signaling.

[0115] Based on the above scheme, the first device can determine at least one magnitude (for example, the L2 first magnitudes) and at least one phase (for example, the L1 first phases) according to the reference signal. The first device can select part or all of the at least one magnitude (for example, the K first magnitudes) and part or all of the at least one phase (for example, the K first phases) to determine the key generation material (for example, the first channel matrix). Compared with the scheme of directly generating the key according to the magnitudes and phases estimated from the reference signal, the above scheme can improve the randomness of the key, thereby helping to improve the security of communication.

[0116] Correspondingly, the second device performs similar operations as S310 to determine at least one phase and at least one magnitude for the reference signal sent by the first device. The second device can perform similar operations as S320 to select K phases and K magnitudes from the at least one phase and the at least one magnitude to determine the channel matrix. The second device can perform similar operations as S330 to generate the key.

[0117] The following describes an example in which the first device determines the L1 first phases.

[0118] In some examples, the L1 first phases can be phases obtained by the first device performing channel estimation on the first reference signal.

[0119] For example, the first device can perform channel estimation on the first reference signal to obtain a channel matrix. For example, the channel matrix can include L1 elements, and phases of the L1 elements can be taken as the L1 first phases. L1 can be equal to L2. Amplitudes of the L1 elements can be taken as the L2 first amplitudes.

[0120] In other words, the L1 first phases can be phases in a channel matrix obtained by the first device.

[0121] In other examples, the L1 first phases can be further processed from phases obtained by the first device performing channel estimation on the first reference signal. Details are described below.

[0122] In some possible implementations, the L1 first phases include L1’ fourth phases and L1” fifth phases. L1’ and L1” are positive integers less than L1. For example, L1 = L1’ + L1”. In other words, the L1 first phases can be composed of the L1’ fourth phases and the L1” fifth phases. However, the present application is not limited thereto, and L1 can also be greater than L1’ + L1”.

[0123] In some examples, the first device can correspond to a first antenna and a second antenna. The first device can receive the first reference signal from the second device through the first antenna and the second antenna. The key generated in S330 can be used to encrypt information sent through the first antenna. The key can be used to encrypt information sent through the second antenna.

[0124] In the case where the first device is a terminal device or a network device, the first antenna and the second antenna corresponding to the terminal device or the network device can be understood as the first antenna and the second antenna being antennas of the terminal device or the network device. In the case where the first device is a component in a terminal device or a network device, the component corresponding to the first antenna and the second antenna can be understood as the first antenna and the second antenna being antennas used in conjunction with the component. Other antennas corresponding to other devices can be understood with reference to the above.

[0125] For example, the first device can subtract a phase estimated from the first reference signal received through the second antenna from a phase estimated from the first reference signal received through the first antenna to obtain a fourth phase. Further, the L1’ fourth phases can be obtained by the first device processing reference signals received through two antennas corresponding to the first device.

[0126] In some examples, the second device can correspond to the first antenna and the second antenna. The second device can send the first reference signal to the first device through the first antenna and the second antenna. The key generated in S330 can be used to decrypt the information sent through the first antenna (i.e., the information sent by the second device). The key can be used to decrypt the information sent through the second antenna.

[0127] The L1" fifth phases can be obtained by the first device processing the reference signals sent by the second device through the two antennas.

[0128] The following describes specific examples of the L1' fourth phases and / or the L1" fifth phases in combination with FIG. 4.

[0129] FIG. 4 is a schematic diagram of channel estimation in a multi-antenna system according to an embodiment of the present application. The first device can correspond to M1 antennas, and the second device can correspond to M2 antennas. M1 can be an integer greater than 1, and / or M2 can be an integer greater than 1. M1 can be equal to M2, or can not be equal to M2.

[0130] The M1 antennas corresponding to the first device can send signals to the M2 antennas corresponding to the second device. The M2 antennas corresponding to the second device can also send signals to the M1 antennas corresponding to the first device. The multi-antenna system shown in FIG. 4 can also be understood as an M1 x M2 multiple input multiple output (MIMO) system.

[0131] In the multi-antenna system shown in FIG. 4, any two antennas corresponding to the first device and any one antenna corresponding to the second device can be regarded as an antenna combination. Any one antenna corresponding to the first device and any two antennas corresponding to the second device can also be regarded as an antenna combination.

[0132] The following describes an antenna combination of two antennas (denoted as antenna 1 and antenna 2) corresponding to the first device and one antenna (denoted as antenna 3) corresponding to the second device. Those skilled in the art can understand that an antenna combination of one antenna corresponding to the first device and two antennas corresponding to the second device is similar to the following example, and thus will not be described in detail.

[0133] The first device can receive a reference signal 1 (e.g., a first reference signal) from the second device. The reference signal 1 can pass through a transmitting channel of the second device, a spatial channel, and a receiving channel of the first device. Wherein, a phase of a channel from the antenna 3 to the antenna 1 (denoted as channel 1) can be denoted as ∠h1, and a phase of a channel from the antenna 3 to the antenna 2 (denoted as channel 2) can be denoted as ∠h2. A random initial phase of the antenna 1 corresponding to the first device as the receiving channel is denoted as A random initial phase of the antenna 2 corresponding to the first device as the receiving channel is denoted as A random initial phase of the antenna 3 corresponding to the second device as the transmitting channel is denoted as

[0134] A phase of the reference signal 1 on the channel 1 and the channel 2 can be expressed by the following formula:

[0135] Wherein, ω c = 2πf c , f c may be a subcarrier frequency of the reference signal 1. τ1 can represent a time delay of the air interface transmission of the reference signal 1 on the channel 1, and τ2 can represent a time delay of the air interface transmission of the reference signal 1 on the channel 2.

[0136] The first device can determine a fourth phase θ 12 according to the following formula:

[0137] It can be understood that the above fourth phase is obtained by processing the reference signal 1 received by the two antennas (i.e., the antenna 1 and the antenna 2, or referred to as the first antenna and the second antenna) corresponding to the first device. Therefore, the above fourth phase θ 12 may belong to L1’ fourth phases.

[0138] In an example of L1” fifth phases, the first antenna and the second antenna correspond to the second device. Specific examples of the L1” fifth phases are similar to the specific examples of the L1’ fourth phases, and will not be described again.

[0139] Based on the above scheme, the first antenna and the second antenna can be two antennas corresponding to the same device, and thus the L1' fourth phases can be the difference between the receiving initial phases of the two antennas corresponding to the same device, and the L1" fifth phases can be the difference between the sending initial phases of the two antennas corresponding to the same device. Those skilled in the art can understand that the antennas corresponding to the same device often use the same clock. Even if the initial phase (for example, the sending initial phase or the receiving initial phase) of one antenna drifts, since the initial phase of the other antenna also drifts, the difference between the initial phases of the two antennas corresponding to the same device is relatively stable. Therefore, the first phase based on which the first device generates the key is relatively stable. Compared with the scheme of generating the key directly based on the initial phase, the above scheme is less affected by the phase drift of the communication parties. Therefore, the above scheme can further improve the consistency of the key.

[0140] In some possible implementations, the first device or the second device can further improve the reciprocity of the key generation material through information interaction. Details are as follows.

[0141] Taking the first device corresponding to the first antenna and the second antenna as an example, the foregoing example can be performed before the key generation stage (for example, before S310). After the foregoing example, the first device obtains the phase θ 12 . Next, through information interaction between the second device and the first device, the first device can obtain the difference (denoted as a phase difference parameter) between the phase θ 12 obtained by the second device (denoted as a phase θ' 12 ). In this way, in the key generation stage, the first device can process the phase obtained by the first device using the phase difference parameter, so that the processed phase is close to the phase obtained by the second device, thereby improving the reciprocity of the key generation material. Details are as follows.

[0142] The first device can send a reference signal 1' to the second device. The reference signal 1' can pass through the sending channel of the first device, the space channel, and the receiving channel of the second device. Wherein, the phase of the channel (denoted as a channel 1') from the antenna 1 to the antenna 3 can be denoted as ∠h'1, and the phase of the channel (denoted as a channel 2') from the antenna 2 to the antenna 3 can be denoted as ∠h'2. The random initial phase of the antenna 1 corresponding to the first device as the sending channel is denoted as The random initial phase of the antenna 2 corresponding to the first device as the sending channel is denoted as The random initial phase of the antenna 3 corresponding to the second device as the receiving channel is denoted as

[0143] For ease of description, it is assumed that the first and second devices operate in time division duplex (TDD) mode. Channel 1 and channel 1' can be considered as the same channel, and channel 2 and channel 2' can be considered as the same channel. The phase of reference signal 1' on channels 1' and 2' can be expressed by the following formula:

[0144] Where, ω c =2πf c f c It can be the subcarrier frequency of reference signal 1'. τ1 can represent the time delay of reference signal 1's over-the-air transmission on channel 1' (or channel 1), and τ2 can represent the time delay of reference signal 1's over-the-air transmission on channel 2' (or channel 2).

[0145] The second device can determine the phase θ′ according to the following formula. 12 :

[0146] The first device can receive the indicated phase θ′ from the second device. 12 The information. Furthermore, the first device can be based on the phase θ. 12 and phase θ′ 12 Determine the phase difference parameters.

[0147] The following assumes that the phase difference parameter is equal to the phase θ. 12 Subtract phase θ′ 12 For example, the phase difference parameter Δθ can be expressed by the following formula.

[0148] in, This is the initial phase difference between two antennas corresponding to the same device (i.e., the first device). Antennas corresponding to the same device often use the same clock. Even Drifting occurs, due to Corresponding drift will also occur. Relatively stable. Similarly, It is also relatively stable. Therefore, the phase difference parameter Δθ is a time-stable initial quantity that is only related to the hardware of the first device. Thus, the above scheme is less affected by the phase drift of the communicating parties.

[0149] After estimating the phase difference parameter Δθ through the above process, during the key generation stage, the first and second devices can interact with the reference signal and perform channel estimation and phase calculation respectively.

[0150] For example, the first device can calculate the phase of the reference signal on channel 1 minus the phase of the reference signal on channel 2 to obtain a first phase (for ease of description, it is assumed below that the first phase belongs to the K first phases screened by the first device). The first device can subtract the phase difference parameter from the first phase to obtain a processed phase. The first device can generate a key according to the processed phase. For example, S330 includes: the first device subtracts the phase difference parameter from the phase of one first element in the first channel matrix to obtain a processed first element; and the first device generates a first key according to the processed first channel matrix, the processed first channel matrix including the processed first element.

[0151] The second device can calculate the phase of the reference signal on channel 1' minus the phase of the reference signal on channel 2', and perform similar operations to S320 and S330 according to the phase to generate a key.

[0152] The above examples take two antennas corresponding to the first device and one antenna corresponding to the second device as an antenna combination, but the present application is not limited thereto. One antenna corresponding to the first device and two antennas corresponding to the second device as an antenna combination can also achieve the effects of the embodiments of the present application.

[0153] The above examples take the first device to determine the phase difference parameter and generate the key according to the phase difference parameter, the first phase screened and the channel estimation in the key generation stage. However, the present application is not limited thereto. In other examples, the first device can directly generate the key according to the first phase, and the second device can determine the phase difference parameter and generate the key based on the phase difference parameter, the phase screened and the channel estimation.

[0154] The device that determines the phase difference parameter and the device that uses the phase difference parameter can be the same device or different devices. The above examples take the device that determines the phase difference parameter and the device that uses the phase difference parameter as the same device, but the present application is not limited thereto. For example, the first device can send the indication information of the phase difference parameter to the second device after determining the phase difference parameter, and the second device can use the phase difference parameter. In this way, the first device can still directly generate the key according to the first phase, and the second device can generate the key based on the phase difference parameter, the phase screened and the channel estimation.

[0155] The above phase difference parameter can be obtained by one channel estimation of the first device and the second device, or can be obtained by multiple channel estimations. In other words, the phase difference parameter can be a statistical value of multiple channel estimations.

[0156] For example, the above antenna combination can share Wherein, C can represent the combination number, and "*" can represent the multiplication sign.

[0157] The channel combination corresponding to each antenna combination can be denoted as <h i ,h j >, i and j are different, and i and j are positive integers less than or equal to For example, the channel between antenna 1 and antenna 3 can be denoted as h1, the channel between antenna 2 and antenna 3 can be denoted as h2, and the channel combination corresponding to the antenna combination shown in FIG. 4 can be denoted as <h1, h2>.

[0158] Wherein, the channel phase pair (or referred to as the phase feature) obtained by each antenna combination can be <θ′ ij -Δθ ij ,θ′ ij >. For example, the channel phase pair shown in FIG. 4 can be <θ′ 12 -Δθ 12 ,θ′ 12 >.

[0159] FIG. 5 is a schematic diagram of antenna combination and channel combination provided by an embodiment of the present application. FIG. 5 takes the first device as BS and the second device as UE as an example. Wherein, the transmission end of the reference signal is denoted as Tx, and the reception end of the reference signal is denoted as Rx.

[0160] FIG. 5 takes a 3*2 MIMO system as an example. M1=3, M2=2, and there are antenna combinations in total. Respective shown by (a) to (i) in FIG. 5. Wherein, each antenna combination can correspond to a channel combination. Each antenna combination can correspond to a phase feature combination. In this way, the 9 antenna combinations can correspond to 9 phase feature combinations respectively, denoted as phase feature combination one to phase feature combination nine.

[0161] Exemplarily, For example, the L1 first phases can be L1 θ′ ij -Δθ ij , or L1 θ′ ij . In other words, there can be L1 uplink-downlink reciprocal channel phase pairs <θ′ ij -Δθ ij ,θ′ ij > between the first device and the second device.

[0162] Exemplarily, L2=M1*M2. For example, there can be L2 uplink-downlink reciprocal channel modulus pairs between the first device and the second device.

[0163] Those skilled in the art can understand that the above examples take the first device and the second device transmitting the reference signals to each other in the TDD mode as an example, but the present application is not limited thereto. For example, the first device and the second device can work in other modes (for example, a frequency division duplexing (FDD) mode).

[0164] In addition, examples in which the first antenna and the second antenna correspond to the second device can refer to the above examples in which the first antenna and the second antenna correspond to the first device, and details are not repeated.

[0165] The following describes examples in which the first device determines the K first phases and the K first amplitudes.

[0166] In some possible implementation manners, S320 includes determining the first channel matrix according to the first index, the second index, the L1 first phases, and the L2 first amplitudes.

[0167] The first index can be an index of the K first phases. In other words, the first index can be used to indicate the K first phases. For example, the first index can represent positions of the K first phases in the L1 first phases. For example, assuming that the first index starts from 0, the first index can be 0, 1, and 3, so that the first, second, and fourth phases in the L1 first phases can belong to the K first phases.

[0168] The second index can be an index of the K first amplitudes. Specific examples are similar to the above examples of the first index, and details are not repeated.

[0169] In some examples, the first index and / or the second index can be determined by the first device. For example, the first device determines positions of phases with better performance in all channel-estimated phases by performance of the phases obtained through previous channel estimation and a key, to generate the first index. For another example, the first device determines positions of amplitudes with better performance in all channel-estimated amplitudes by performance of the amplitudes obtained through previous channel estimation and a key, to generate the second index.

[0170] In other examples, the first index and / or the second index can be predefined or preconfigured.

[0171] In still other examples, the first index and / or the second index can be indicated by the second device. For example, the second device can send indication information of the first index and / or the second index to the first device. The first device can determine the first index and / or the second index according to the indication information.

[0172] The above examples can be combined with each other. For example, the first index can be determined by the first device, and the second index can be predefined. For another example, the first index can be preconfigured, and the second index can be determined by the second device.

[0173] Based on the above scheme, the first device can filter out K first amplitudes and K first phases from L1 first amplitudes and L1 first phases according to the first index and the second index, and the processing overhead is small.

[0174] The following describes an example of determining the first index.

[0175] In some possible implementation manners, the first index is an index of the K second phases, and positions of the K second phases in the L1 second phases are the same as positions of the K first phases in the L1 first phases.

[0176] The L1 second phases can be determined by a downlink reference signal or an uplink reference signal. The L1 second phases and the L1 first phases can be determined in a similar manner. The difference is that the L1 first phases are determined in the key generation stage, and the L1 second phases are determined before the key generation stage.

[0177] The first index is an index of the K second phases. In other words, the first index can be used to indicate the K second phases. For example, the first index can represent positions of the K second phases in the L1 second phases.

[0178] The above scheme can also be understood as follows: Before the key generation stage, the first device, the second device, or another device can select K second phases that satisfy a certain property from the L1 second phases, and record positions of the K second phases in the L1 second phases as the first index.

[0179] In the key generation stage, the first device can select K first phases from the L1 first phases according to the above first index. It can be understood by those skilled in the art that the K first phases are more likely to satisfy a property similar to the K second phases.

[0180] The following describes examples of the property satisfied by the K second phases. The examples are respectively referred to as property example 1 and property example 2.

[0181] Property example 1: An average uplink-downlink difference of the K second phases can be less than or equal to a first threshold value.

[0182] The average uplink-downlink difference of the K second phases can be determined according to the K second phases and K third phases of the L1 third phases. For example, the average uplink-downlink difference of one of the K second phases can be the standard deviation of the difference between the second phase and one of the K third phases. As can be appreciated by one skilled in the art, the smaller the average uplink-downlink difference of the K second phases, the better the consistency of the key generated according to the K second phases.

[0183] The positions of the K third phases in the L1 third phases are the same as the positions of the K first phases in the L1 first phases. In other words, the K third phases in the L1 third phases correspond one-to-one to the K second phases in the L1 second phases.

[0184] The L1 second phases and the L1 third phases can be determined according to the uplink reference signal and the downlink reference signal respectively, or determined according to the downlink reference signal and the uplink reference signal respectively. For example, the L1 second phases are determined according to the uplink reference signal, and the L1 third phases are determined according to the downlink reference signal. Alternatively, the L1 second phases are determined according to the downlink reference signal, and the L1 third phases are determined according to the uplink reference signal.

[0185] For example, the first threshold value can be set according to the requirement for key consistency, for example, the first threshold value can be 0.1.

[0186] The average uplink-downlink difference can also be referred to as reciprocity difference, reciprocity parameter or other names, which are not limited in the present application.

[0187] For example 2, the average correlation coefficient of the K second phases can be less than or equal to a second threshold value.

[0188] For example, the second threshold value can be set according to the requirement for key randomness, for example, the second threshold value can be 0.2.

[0189] The following describes the operation process of determining the first index by taking the first device as an example. However, the present application does not limit the subject of determining the first index, and the first index can also be determined by the second device or other devices.

[0190] The following describes the process of determining the first index by taking the first device as a network device and the second device as a terminal device, and taking the second phase as a phase determined by the uplink reference signal and the third phase as a phase determined by the downlink reference signal as an example. In some possible implementations, the process of determining the first index can include S11-S15, which are described in detail as follows.

[0191] S11, the network device and the terminal device can perform N rounds of channel estimation, and obtain N pairs of uplink and downlink channel matrices respectively. Among them, the network device can obtain L1 phases (denoted as second phases), denoted as Wherein, U can represent uplink. The terminal device can obtain L1 phases (denoted as third phases), denoted as Wherein, D can represent downlink. Wherein, θ(n) can represent the phase obtained in the n-th round of N rounds of channel estimation.

[0192] S12, the terminal device can send L1 third phases to the network device. The network device can calculate the uplink and downlink difference of the i-th second phase in the L1 second phases

[0193] For example, the formula is The network device can calculate the average uplink and downlink difference according to the uplink and downlink difference of different n values Wherein, the average uplink and downlink difference can also be called standard deviation, and std() can be a standard deviation function.

[0194] The network device can retain L11 second phases in the L1 second phases, and the average uplink and downlink difference of the L11 second phases is less than or equal to the first threshold Thr1. Exemplarily, the first device can obtain a set of L11 second phases Wherein, Cardinality() can represent the cardinality function, which can be used to calculate the number of elements in

[0195] S13, the network device can calculate the correlation between any two of the L11 second phases. Denote the correlation set of the L11 second phases as Wherein

[0196] S14: The first device selects all combinations with a number of K from the L11 second phases, and calculates the average correlation coefficient of each combination.

[0197] For example, assuming that the L11 second phases obtained in S13 are The first device can select K=3 second phases from the L11=4 second phases for key generation, and there are four combinations Wherein, the average correlation coefficient of combination is The average correlation coefficients of other combinations are not described.

[0198] ​​S15, the first device determines a combination in which the average correlation coefficient is less than or equal to a second threshold. The second phases in the combination are the K second phases described above. The positions of the K second phases in the combination in the L1 second phases can be the first indexes.

[0199] Exemplarily, the second threshold can be the average correlation coefficient of the combination in which the average correlation coefficient is the smallest in the combinations obtained by S14. In other words, one example of S15 can be that the first device determines the combination in which the average correlation coefficient is the smallest in the combinations obtained by S14, and the second phases in the combination are the K second phases described above. For example, the first indexes wherein, arg min() can represent the index of the K second phases (K = 3) when the function reaches the minimum value.

[0200] In the key generation phase, the first indexes The corresponding second phases can be used to generate the key.

[0201] The above S11 to S15 take the first device determining the first indexes according to the second phases obtained by the uplink reference signals as an example. However, the present application is not limited thereto. For example, the execution subject of the above S11 to S15 can also be the second device or other devices. For another example, the above second phases can also be downlink reference phases.

[0202] Based on the above scheme, the second phases corresponding to the first indexes meet the requirements of lower correlation and better reciprocity. Therefore, the K first phases corresponding to the first indexes meet the requirements of lower correlation and better reciprocity with a high probability. The above scheme can improve the quality of the K first phases used to generate the key, thereby further improving the randomness and consistency of the key.

[0203] The examples of determining the second indexes are similar to the examples of determining the first indexes, and the examples of determining the second indexes are briefly introduced below. The parts not introduced can be referred to the foregoing examples of the first indexes.

[0204] In some possible implementation manners, the second indexes are indexes of the K second amplitudes, and positions of the K second amplitudes in the L2 second amplitudes are same as positions of the K first amplitudes in the L2 first amplitudes.

[0205] The second indexes are indexes of the K second amplitudes. In other words, the second indexes can be used to indicate the K second amplitudes. For example, the second indexes can represent positions of the K second amplitudes in the L2 second amplitudes.

[0206] The above scheme can also be understood as follows: before the key generation phase, the first device, the second device, or other devices can select K second amplitudes that satisfy certain properties from the L2 second amplitudes, and record the positions of the K second amplitudes in the L2 second amplitudes as second indexes.

[0207] In the key generation phase, the first device can select K first amplitudes from the L2 first amplitudes according to the above second indexes. Those skilled in the art can understand that the K first amplitudes have a high probability of satisfying similar properties to the K second amplitudes.

[0208] Examples of the properties satisfied by the K second amplitudes are described below. They are respectively referred to as property example 3 and property example 4.

[0209] Property example 3: the average up-down difference of the K second amplitudes is less than or equal to a third threshold value.

[0210] The average up-down difference of the K second amplitudes is determined according to the K second amplitudes and K third amplitudes from the L2 third amplitudes, and the positions of the K third amplitudes in the L2 third amplitudes are the same as the positions of the K first amplitudes in the L2 first amplitudes.

[0211] Property example 4: the average correlation coefficient of the K second amplitudes is less than or equal to a fourth threshold value.

[0212] The K second amplitudes are determined according to uplink reference signals, the K third amplitudes are determined according to downlink reference signals, or the K second amplitudes are determined according to downlink reference signals, and the K third amplitudes are determined according to uplink reference signals.

[0213] The following describes an example in which the first device is a network device, the second device is a terminal device, the second amplitude is an amplitude determined by an uplink reference signal, and the third amplitude is an amplitude determined by a downlink reference signal. In some possible implementations, the process of determining the second indexes can include S21 to S25, which are described in detail below.

[0214] S21, the network device and the terminal device can perform N rounds of channel estimation to obtain N pairs of uplink and downlink channel matrices. The network device can obtain L2 amplitudes (referred to as second amplitudes), denoted as The terminal device can obtain L2 amplitudes (referred to as third amplitudes), denoted as

[0215] Other descriptions can be referred to the description of S11.

[0216] S22, the terminal device can send the L2 third amplitudes to the network device. The network device can calculate the up-down difference of the i-th second amplitude in the L2 second amplitudes

[0217] For example, the formula is The network device can obtain the difference between the uplink and downlink according to different n values The average difference between the uplink and downlink can be calculated The average difference between the uplink and downlink can also be referred to as the standard deviation, and std() can be a standard deviation function.

[0218] The network device can retain L21 second amplitudes from the L2 second amplitudes, where the average difference between the uplink and downlink of the L21 second amplitudes is less than or equal to a third threshold Thr2. For example, the first device can obtain a set of L21 second amplitudes Where Cardinality() can represent a cardinality function, which can be used to calculate the number of elements in .

[0219] S23, the network device can calculate the correlation between any two second amplitudes in the L21 second amplitudes. Let the obtained correlation set of the L21 second amplitudes be Where

[0220] S24: The first device selects all combinations of K number of second amplitudes from the L21 second amplitudes, and calculates the average correlation coefficient of each combination.

[0221] For example, assume that the L21 second amplitudes obtained by S23 are The first device can select K=3 second amplitudes from the L21=4 second amplitudes for key generation, and there are four combinations Where the average correlation coefficient of the combination is The average correlation coefficients of other combinations are not described in detail.

[0222] S25, the first device determines the combination whose average correlation coefficient is less than or equal to a fourth threshold. The second amplitudes in the combination are the K second amplitudes described above. The positions of the K second amplitudes in the combination in the L2 second amplitudes can be the second indexes.

[0223] For example, the second threshold can be the average correlation coefficient of the combination with the smallest average correlation coefficient in the combinations obtained by S24. In other words, an example of S25 can be that the first device determines the combination with the smallest average correlation coefficient in the combinations obtained by S24, and the second amplitudes in the combination are the K second amplitudes described above. For example, the second indexes Where arg min() can represent the index (K=3) of the K second amplitudes when the function obtains the minimum value.

[0224] In the key generation phase, the second index The corresponding second amplitude can be used to generate the key.

[0225] Based on the above scheme, the second amplitude corresponding to the second index satisfies the requirement of low correlation and good reciprocity. Therefore, the K first amplitudes corresponding to the second index satisfy the requirement of low correlation and good reciprocity with a high probability. The above scheme can improve the quality of the K first amplitudes used to generate the key, thereby further improving the randomness and consistency of the key.

[0226] Some examples of generating the key are introduced below.

[0227] In some implementations, S330 includes: determining, by the first device, a second channel matrix according to the first channel matrix, wherein the second channel matrix includes K second elements, and the phase of each of the K second elements is the sum of the first phase and a first parameter; and generating, by the first device, the key according to the second channel matrix. The first parameter can be a specific phase value.

[0228] For example, the first device can add the phase of the first element in the first channel matrix (i.e., the first phase) to the first parameter to obtain a new phase. The new phase can be used as the phase of the element (i.e., the second element) in the new channel matrix (i.e., the second channel matrix). In other words, the first device can further process the first channel matrix determined by the channel estimation and the screening to obtain the second channel matrix, and then generate the key according to the second channel matrix.

[0229] In some examples, the first device can add the K first phases to the K first parameters respectively to obtain the phase of the K second elements. The K first parameters can be the same parameters or different parameters. For example, two of the K first parameters can be different.

[0230] For example, all of the K first parameters can be 0. For another example, some of the K first parameters can be 0. In other words, some of the K first phases can be added to some parameters respectively, while the other first phases remain unchanged, thereby obtaining the phase of the K second elements.

[0231] For example, the first parameter can be used to make the distribution of the K first phases between 0 and 2π, or between -π and π. Examples of the first parameter are introduced below in connection with FIG. 6.

[0232] FIG. 6 is a diagram of distribution of K first phases according to an embodiment of the present application. The horizontal axis of FIG. 6 can be time (e.g., in microseconds), and the vertical axis can be phase (e.g., in radians).

[0233] Under certain channel conditions (e.g., a static scene), the time delay of the channel varies less, and thus the range of the obtained phase varies less. For example, as shown in FIG. 6, the range of the phase varies between 0.05 and 0.2, and the range is small.

[0234] To improve the rate of key generation, the phases of the key generation material can approach a uniform distribution in [0, 2π], or a uniform distribution in [-π, π]. Illustratively, the key generation material can be a channel matrix. Singular value quantization can be performed on the channel matrix to generate a key. Those skilled in the art can understand that, when the phase approaches a uniform distribution in [0, 2π], or a uniform distribution in [-π, π], the singular values of the channel matrix formed by the phase have a large range, and thus the rate of key generation is high. Therefore, the phases of the first elements in the first channel matrix can be preprocessed before key generation.

[0235] Illustratively, assume that K = 4. Assume that the indices of the K first phases are 1, 2, 3, and 4, and thus the K first phases are

[0236] In the related scheme 1, the processed phases can be calculated as where min can represent a minimum function, and max can represent a maximum function. i = 1, 2, 3, 4. The range of the processed phases can be normalized to [0, 2π]. However, the related scheme 1 also amplifies the up-down difference of the phases, which can reduce the consistency of the key. In addition, the related scheme 1 can increase outliers in multiple phases (e.g., ).The increase of the outliers can affect the result of normalization, and thus increase the average up-down difference and reduce the consistency of the key.

[0237] Some examples provided by embodiments of the present application are described below.

[0238] The phase of the i-th second element in the K second elements can be where may represent a first parameter. Wherein, The formula can represent a uniform distribution on 0 to 2π.

[0239] Based on the above scheme, the first device can add the first parameter to the K first phases to obtain the phases of the K second elements. The phases of the second elements can be uniformly distributed in a larger range, thereby improving the rate of key generation. In addition, compared with the related scheme 1, the above scheme can not increase the up-down difference of the phases of the second elements, thereby guaranteeing the consistency of the generated key.

[0240] In some possible implementation ways, the first parameter is predefined or preconfigured.

[0241] In some possible implementation ways, the method 300 further includes that the first device receives first information from the second device, the first information being used to indicate the first parameter. Correspondingly, the second device sends the first information to the first device.

[0242] In some possible implementation ways, the method 300 further includes that the first device receives first information from the second device, the first information being used to indicate the first parameter. Correspondingly, the second device sends the first information to the first device.

[0243] Based on the above scheme, the first parameter can be a parameter known by both parties of communication (for example, the first device and the second device), so that both parties of communication can use the same parameter to determine the key generation material (for example, the second channel matrix), thereby improving the consistency of the key.

[0244] In some possible implementation ways, the initial phase of the first reference signal is determined according to a second parameter. The second parameter can be a parameter determined by the second device. In this way, the expression of the L1 first phases can include the second parameter (or the expression of the K first phases can include the second parameter). For ease of description, the above content can also be briefly described as: the L1 first phases carry the second parameter.

[0245] The method 300 can further include that the first device sends a second reference signal to the second device, the initial phase of the second reference signal being determined according to the first parameter. Correspondingly, the second device receives the second reference signal from the first device.

[0246] The initial phase of the first reference signal is determined according to the second parameter, which can be understood as that the expression of the initial phase of the first reference signal includes the second parameter. For example, the second device can set the initial phase of the first reference signal as the second parameter or an expression including the second parameter. Considering the random initial phase of the transmission channel of the second device, the actual transmitted initial phase of the first reference signal can not be strictly equal to the second parameter, but those skilled in the art can understand that the expression of the actual transmitted initial phase of the first reference signal contains the second parameter.

[0247] The initial phase of the second reference signal is determined according to the first parameter. The above can be understood with reference to the above description, and will not be described in detail.

[0248] An example of the above scheme is described below.

[0249] Exemplarily, the first device can determine the first parameter and carry it in the reference signal (e.g., the second reference signal) sent by the first device.

[0250] Correspondingly, the second device can determine the second parameter and carry it in the reference signal (e.g., the first reference signal) sent by the second device.

[0251] Further, the first device can perform channel estimation on the reference signal carrying the second parameter received from the second device to obtain a phase carrying the second parameter. Then, the first device can add the phase (carrying the second parameter) to the first parameter determined by the first device to determine the phase of the second element (the phase carrying the sum of the first parameter and the second parameter).

[0252] Correspondingly, the second device can perform channel estimation on the reference signal carrying the first parameter received from the first device to obtain a phase carrying the first parameter. Then, the second device can add the phase (carrying the first parameter) to the second parameter determined by the second device to determine a phase carrying the sum of the first parameter and the second parameter.

[0253] The above "A carries B" can be understood as A is related to B, or the expression of A contains B. For example, the phase carrying the second parameter can be understood as the phase is related to the second parameter, or the expression of the phase contains the second parameter.

[0254] An example of the above scheme is described below in combination with the antenna combination shown in FIG. 4.

[0255] In the key generation phase, the reference signals (e.g., the second reference signal and the first reference signal) sent by the first device and the second device can increase an initial random phase compared with the statistical phase. The above initial random phase is generated by the first device and the second device at will. For example, the second device can increase a random initial phase on the first reference signal sent to the antenna 1 and the antenna 2 respectively And Wherein, The first device can estimate the first reference signal to obtain phases ∠h1 and ∠h2 as follows:

[0256] Wherein, the description of the above parameters can be referred to the description of FIG. 4, and will not be described in detail.

[0257] The first phase θ1 obtained by the first device is 12For example, the first parameter can be a random initial phase.

[0258] The second parameter can be a random initial phase. The first parameter can be subject to a uniform distribution over -π to π.

[0259] The second parameter can be determined by the second device. The first device can determine the first phase based on the first parameter. That is, the first phase is added to the first parameter to obtain the phase of the second element for key generation.

[0260] Similarly, the first device can also add a random initial phase and to the second reference signal transmitted by the antenna 1 and the antenna 2 respectively when transmitting the second reference signal.

[0261] where ω c = 2πf c , f c may be the subcarrier frequency of the second reference signal. τ r may represent the time delay of the air interface transmission of the second reference signal on the channel 1', and τ2may represent the time delay of the air interface transmission of the second reference signal on the channel 2'.

[0262] The first phase' θ' of the second device can be determined according to the following formula: 12

[0263] The second parameter can be determined by the second device. The second device can determine the first phase' based on the second parameter. That is, the first phase' is added to the second parameter to obtain the phase for key generation.

[0264] Further, in some possible implementations, the above scheme can also be combined with an example of a "phase difference parameter". For example, the first device can use a phase difference parameter Δθ 12 In this way, the first device can add the first phase, the phase difference parameter and the first parameter to obtain The result is closer to the of the second device, thereby improving the consistency of the key.

[0265] ​Based on the above scheme, the initial phase of the first reference signal can be determined according to the second parameter. In this way, the first device can add the K first phases (carrying the second parameter) determined by the first reference signal to the first parameter, so as to determine the phase for generating the key together with the opposite end (for example, the second device) of the first device. The initial phase of the second reference signal sent by the first device can be determined according to the first parameter. In this way, the opposite end of the first device can add the phase (carrying the first parameter) determined by the second reference signal to the second parameter, so as to determine the phase for generating the key together with the first device. In the above scheme, the first device and the opposite end of the first device determine the parameters without plaintext interaction, so that the phase for generating the key is uniformly distributed in a larger range. Therefore, the above scheme can improve the rate of key generation while ensuring security.

[0266] In some examples, the key can be used for single-threshold quantization determination of the key generation material.

[0267] In other examples, the key can be used for double-threshold quantization determination of the key generation material.

[0268] Exemplarily, the key generation material can be the first channel matrix, the second channel matrix, the first channel matrix processed based on the phase difference parameter, or the second channel matrix processed based on the phase difference parameter.

[0269] The following describes an example of generating a key according to a quantization threshold.

[0270] In some possible implementations, the key is determined according to a third parameter and a quantization threshold. For example, the key generated by the first device can be determined by double-threshold quantization of the third parameter. The threshold of the double-threshold quantization is the quantization threshold.

[0271] The third parameter can also be referred to as a spectral norm of the key generation material. For example, the third parameter can be a spectral norm of the first channel matrix or a spectral norm of the second channel matrix. For another example, the third parameter can be a spectral norm of the first channel matrix processed based on the phase difference parameter, or a spectral norm of the second channel matrix processed based on the phase difference parameter.

[0272] The spectral norm can also be referred to as a maximum singular value or other names, which are not limited in the present application.

[0273] The quantization threshold can be determined according to K. For example, the quantization threshold can be positively correlated with K. For another example, the quantization threshold can be linearly correlated with K. 1 / 4 In the embodiments of the present application, K and K can be replaced with each other, and are not distinguished.

[0274] Based on the above scheme, the quantization threshold can be determined according to K. In this case, the greater the value of K, the higher the consistency of the key. Therefore, by using the above quantization threshold, the consistency of the key can be controlled by the value of K.

[0275] Optionally, the quantization threshold is 2σ e K 1 / 4 .

[0276] wherein σ e may be the maximum standard deviation of the average up-down line difference of the K first elements or the maximum standard deviation of the average up-down line difference of the K second elements.

[0277] An example of the maximum standard deviation of the average up-down line difference of the K first elements is introduced below.

[0278] The average up-down line difference of the K first elements can be determined according to the K second phases, the K third phases, the K second amplitudes, and the K third amplitudes.

[0279] Exemplarily, the maximum standard deviation of the average up-down line difference of the K first elements wherein, may be the average up-down line difference of the K first elements.

[0280] Exemplarily, the average up-down line difference of the K first elements may represent the n-th time in the N rounds of channel estimation.

[0281] wherein, may be the K second phases. may be the K third phases. Wherein i may represent the first index.

[0282] wherein, may be the K second amplitudes, may be the K third amplitudes. Wherein i may represent the second index.

[0283] An example of the maximum standard deviation of the average up-down line difference of the K second elements is introduced below.

[0284] The average up-down line difference of the K second elements can be determined according to the K second phases, the K third phases, the K second amplitudes, the K third amplitudes, and the first parameter.

[0285] Exemplarily, the maximum standard deviation of the average up-down line difference of the K second elements wherein, may be the average up-down line difference of the K second elements.

[0286] Exemplarily, the average up-down line difference of the K second elements n can represent the n-th time in N rounds of channel estimation.

[0287] wherein, may be the sum of K second phases and the first parameter. may be the sum of K third phases and the first parameter. Wherein, i can represent the first index.

[0288] wherein, may be K second amplitudes, may be K third amplitudes. Wherein, i can represent the second index.

[0289] The descriptions of the above second phase, third phase, second amplitude and third amplitude refer to the previous examples and will not be repeated.

[0290] In some possible implementations, the above quantization threshold can be predefined or preconfigured. In other possible implementations, the above quantization threshold can be determined by the first device, the second device or other devices. Further, the device determining the above quantization threshold can send indication information of the quantization threshold to the first device and / or the second device.

[0291] For example, in the case of the quantization threshold being 2σ e K 1 / 4 , the following can be obtained:

[0292] ||(|H1|)| op -|(|H2|)| op |≤|H1-H2| op =σ e |S| op

[0293] Wherein, the matrix H1 can be the first channel matrix or the second channel matrix determined according to the uplink reference signal, and the matrix H2 can be the first channel matrix or the second channel matrix determined according to the downlink reference signal. The elements in the matrix S are subject to independent identical distribution (IID) and standard Gaussian distribution. may represent the probability that the difference between the singular values of the channel matrices obtained by the uplink and the downlink respectively exceeds the threshold value 2σ e K 1 / 4 . The formula “||H1-H2||” represents the operator norm. op

[0294] It can be seen that the larger K is, the smaller the above probability is, and thus the higher the consistency rate of key generation is.

[0295] ​Based on the above quantization threshold, the consistency of the key can be further improved.

[0296] Exemplarily, it is assumed that K=4. It is assumed that the indexes of the K first amplitudes are 1, 2, 3 and 4, so that the K first amplitudes are {h1, h2, h3, h4}. It is assumed that the indexes of the K first phases are 1, 2, 3 and 4, so that the K first phases are {θ1, θ2, θ3, θ4}. The indexes of the K first amplitudes can also be discontinuous, for example, 1, 3, 4, 6.

[0297] Exemplarily, the first device determines the first channel matrix H(n) in the n th channel estimation in N rounds of channel estimation.

[0298] The first device performs singular value decomposition (SVD) on the first channel matrix H(n) to obtain the maximum singular value (or called spectral norm) {σ(n)}. The above {σ(n)} can also be referred to as a third parameter.

[0299] An example of performing SVD on the second channel matrix to obtain the spectral norm of the second channel matrix is described above and will not be repeated.

[0300] FIG. 7 is a schematic diagram of a double-threshold quantization provided by an embodiment of the present application. The horizontal and vertical coordinates and units in FIG. 7 can be referred to the example of FIG. 6 and will not be repeated.

[0301] The first device can perform double-threshold quantization on the time sequence of the third parameter within a certain time. For example, as shown in FIG. 7, according to the mean of the third parameter and the above quantization threshold Thr Q = 2σ e K 1 / 4 , the upper bound (UB) of quantization and the lower bound (LB) of quantization can be determined. Exemplarily, UB = mean + Thr Q ; LB = mean - Thr Q .

[0302] According to the relationship between the time sequence of the third parameter and the UB and LB, there are three kinds of quantization results. If an element in the time sequence of the third parameter is less than LB, it is quantized to bit 0; if an element in the time sequence of the third parameter is greater than LB and less than UB, it is quantized to intermediate state X; if an element in the time sequence of the third parameter is greater than UB, it is quantized to bit 1.

[0303] If one element in the time series of the third parameter is equal to LB, it can be quantized to bit 0 or intermediate state X. If one element in the time series of the third parameter is equal to UB, it can be quantized to bit 1 or intermediate state X, which is not limited in the present application.

[0304] In some possible implementation manners, the first device and the second device can interact the indexes of the bits quantized to X respectively determined by the first device and the second device, and remove the bits corresponding to the indexes, so as to determine the key.

[0305] Exemplarily, it is assumed that the first device can determine the string "001X11010X" according to the third parameter and the quantization threshold. It is assumed that the second device determines the string "0X1110110X".

[0306] The first device can send indication information indicating indexes 4 and 10. The second device can send indication information indicating indexes 2 and 10.

[0307] In this way, the first device can remove the bits of indexes 2, 4 and 10, and determine the key as 0111010. The third device can remove the bits of indexes 2, 4 and 10, and determine the key as 0110110.

[0308] For ease of description, it is defined that A 2 = K. Exemplarily, Wherein, may represent rounding down. The quantization threshold can also be represented as 2σ e A 1 / 2 or

[0309] The following describes the interaction between the network device and the terminal device as an example.

[0310] In scene example 1, the following terminal device can be the first device, and the network device can be the second device.

[0311] In scene example 2, the following terminal device can be the second device, and the network device can be the first device.

[0312] FIG. 8 is a schematic flowchart of another communication method 700 provided by an embodiment of the present application. The following briefly introduces the key generation process in the method 700.

[0313] The method 700 takes the network device determining the first index and the second index as an example. In the method 700, the process of key generation can be divided into two stages. In the first stage, the network device and the terminal device can estimate the statistical characteristics (for example, the amplitude and the phase) of the uplink and downlink channels, determine the first index and the second index and other parameters, and prepare for the subsequent key generation. In the second stage, the network device and the terminal device can use the parameters generated in the first stage to synthesize the key material in a predetermined manner, and complete the key generation.

[0314] In the whole process of key generation, the first stage and the second stage can not be performed continuously. In a possible implementation, the network device and the terminal device perform the estimation of the statistical characteristics in the first stage periodically in a long period. After completing the estimation of the statistical characteristics, the network device can update the parameters required for the key generation in the second stage once. In the method 700, the updating of the parameters can be embodied as updating the second configuration information. In the case where the second configuration information is not updated, the network device and the terminal device can use the existing second configuration information to perform the key generation in the second stage.

[0315] The operations of the method 700 will be described below in combination with FIG. 8.

[0316] S710, the network device sends first configuration information to the terminal device, and the first configuration information can be used to configure a time-frequency resource for sending a reference signal. Correspondingly, the terminal device receives the first configuration information from the network device.

[0317] For example, the first configuration information can be carried in RRC signaling or other messages.

[0318] The first stage will be described below.

[0319] S720, the network device sends a first trigger signal to the terminal device, and the first trigger signal can be used to trigger the terminal device to perform the operation in the first stage. Correspondingly, the terminal device receives the first trigger signal from the network device.

[0320] For example, the operation in the first stage can include S722 to S730.

[0321] S722, the network device and the terminal device interact with the reference signal, and respectively perform channel estimation.

[0322] For example, the network device and the terminal device can respectively send the reference signal on the time-frequency resource indicated by the first configuration information.

[0323] For example, S722 can be performed in a TDD mode. For example, the network device sends the reference signal to the terminal device on a TDD frequency band. The terminal device sends the reference signal to the network device on the TDD frequency band.

[0324] The network device performs channel estimation to obtain the uplink channel characteristics (e.g., the second phase and the second amplitude). The terminal device performs channel estimation to obtain the downlink channel characteristics. For example, the third phase and the third amplitude. For another example, the channel coefficients or other parameters reflecting the channel characteristics.

[0325] S724, the terminal device sends the indication information of the uplink channel characteristics to the network device. Correspondingly, the network device receives the indication information of the uplink channel characteristics of the terminal device.

[0326] For example, the indication information of the uplink channel characteristics can be used to indicate the uplink channel characteristics determined by the terminal device.

[0327] S726, the network device performs statistical characteristic estimation according to the uplink channel characteristics and the downlink channel characteristics.

[0328] Exemplarily, after S726, the network device can obtain at least one of the first index, the second index, the phase difference parameter, the quantization threshold or the first parameter. The first parameter can be a parameter known by both the network device and the terminal device, so that the phases used to generate the key are uniformly distributed in a larger range, thereby improving the rate of key generation.

[0329] S728, the network device performs channel evaluation and selection.

[0330] For example, the network device can evaluate and select multiple channels of a multi-antenna system. The multi-antenna system (e.g., the system shown in FIG. 4) can have multiple channels. In the key generation algorithm, all the channels can not be used. The network device can evaluate the reciprocity and correlation of different channels in this stage, and select several channels with good reciprocity and low correlation for key generation.

[0331] S730, the network device sends the second configuration information to the terminal device, and the second configuration information can indicate the key generation parameter. Correspondingly, the terminal device receives the second configuration information from the network device.

[0332] The key generation parameter can be used to indicate at least one of the first index, the second index, the phase difference parameter, the quantization threshold or the first parameter. The first parameter can be a parameter known by both the network device and the terminal device, so that the phases used to generate the key are uniformly distributed in a larger range, thereby improving the rate of key generation.

[0333] The following introduces an example of the second stage.

[0334] S740, the network device sends a second trigger signal to the terminal device, and the second trigger signal can be used to trigger the terminal device to perform a second-stage operation. Correspondingly, the terminal device receives the second trigger signal from the network device.

[0335] For example, the second-stage operation can include S742-S746.

[0336] S742, the network device and the terminal device interact reference signals, respectively performing channel estimation.

[0337] For example, the network device and the terminal device can respectively send reference signals on time-frequency resources indicated by the first configuration information.

[0338] Exemplarily, S742 can be performed in a TDD mode. For example, the network device sends a reference signal to the terminal device on a TDD frequency band. The terminal device sends a reference signal to the network device on the TDD frequency band.

[0339] Taking the network device as the first device, the network device can obtain L1 first phases and L2 first amplitudes by performing S732.

[0340] Taking the terminal device as the first device, the terminal device can obtain L1 first phases and L2 first amplitudes by performing S732.

[0341] S744, the terminal device and the network device respectively perform key material extraction and synthesis.

[0342] Taking the network device as the first device, the network device can perform any of the examples in S320.

[0343] Taking the terminal device as the first device, the terminal device can perform any of the examples in S320.

[0344] S746, the terminal device and the network device respectively perform key generation.

[0345] Taking the network device as the first device, the network device can perform any of the examples in S330.

[0346] Taking the terminal device as the first device, the terminal device can perform any of the examples in S330.

[0347] Exemplarily, in S746, the network device and the terminal device can interact information to negotiate the generation of the key. For example, the network device and the terminal device can interact an index corresponding to a bit of a quantized value X as an intermediate state, which can be referred to the description of FIG. 7.

[0348] The embodiments of the present application can be applied to an O-RAN scenario. For example, the network device in the method 700 can be split into a first network element and a second network element. The first network element can be an O-CU, and the second network element can be an O-DU and / or an O-RU.

[0349] The operations performed by the network device in S710 and S720 can be performed by the first network element.

[0350] The operations performed by the network device in the method 700 other than S710 and S720 can be performed by the second network element. For example, the O-DU and the O-RU can jointly complete the sending of the signal and the channel estimation (for example, S722, S724, S730, S740, or S742). For another example, the operations of the statistical feature estimation, the channel evaluation and selection, and the key material extraction can be implemented by the O-DU network element. For example, the O-DU can perform S726, S728, S744, or S746.

[0351] In some possible implementations, after S746, the method 700 further includes that the second network element sends the key to the first network element. Correspondingly, the first network element receives the key from the second network element. In other words, the second network element can deliver the key to the first network element.

[0352] The following describes a device embodiment corresponding to the method embodiment of the present application. The following only briefly introduces the device, and the specific implementation steps and details of the scheme can be referred to the foregoing method embodiments.

[0353] To implement the functions in the method provided by the present application, the communication device can include hardware structures and / or software modules to implement the above functions in the form of hardware structures, software modules, or hardware structures plus software modules. Whether a certain function in the above functions is implemented in the form of hardware structure, software module, or hardware structure plus software module depends on the specific application and design constraints of the technical solution.

[0354] FIG. 9 is a schematic block diagram of a communication device 1000 according to an embodiment of the present application. The communication device 1000 includes a processor 1010 and a communication interface 1020. Optionally, the processor 1010 and the communication interface 1020 can be connected to each other through a bus. The communication device 1000 can be the first device or the second device.

[0355] Optionally, the communication device 1000 can also include a memory 1040. The memory 1040 includes, but is not limited to, a random access memory (RAM), a read only memory (ROM), a cache, an erasable programmable read only memory (EPROM), a synchronous dynamic random access memory (SDRAM), a hard disk drive (HDD), a solid-state drive (SSD), or a compact disc read-only memory (CD-ROM). The memory 1040 is used for storing relevant instructions and / or data. The memory 1040 can be integrated with the processor 1010 or provided separately.

[0356] The processor 1010 can include one or a combination of a central processing unit (CPU), an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a microprocessor unit (MPU), a microcontroller unit (MCU), a graphics processing unit (GPU), a field programmable gate array (FPGA), an artificial intelligence processor (AI processor), or a neural processing unit (NPU). In the case of the processor 1010 being a CPU, the CPU can be a single-core CPU or a multi-core CPU. However, the present application is not limited thereto, and the processor 1010 can be one or more GPUs, and can also be one or more tensor processing units (TPUs). Among them, the processor 1010 can be a signal processor, a chip, or other integrated circuits that can implement the method of the present application, or a part of the foregoing processor, chip, or integrated circuit for processing functions. In addition, the communication interface 1020 can also be an input / output interface for input or output of signals or data, and can also be an input / output circuit.

[0357] Exemplarily, the communication apparatus 1000 is a first apparatus, and the processor 1010 is configured to perform the following operations: receiving a first reference signal, the first reference signal being used to determine L1 first phases and L2 first amplitudes, L1 and L2 being positive integers; determining a first channel matrix according to the L1 first phases and the L2 first amplitudes, the first channel matrix including K first elements, phases of the K first elements being K first phases in the L1 first phases, and amplitudes of the K first elements being K first amplitudes in the L2 first amplitudes, K being a positive integer less than or equal to L1 and less than or equal to L2; and generating a key according to the first channel matrix.

[0358] In a possible implementation, the communication interface 1020 can be a transceiver. The transceiver can include a transmitter and a receiver, the transmitter being configured to perform a transmitting operation, and the receiver being configured to perform a receiving operation. For example, the processor 1010 is configured to control the transceiver to receive and / or transmit signals.

[0359] In a possible implementation, the communication interface 1020 can also be a communication circuit, a pin, an input / output interface, a bus, etc.

[0360] It should be noted that the communication apparatus 1000 can include a transmitter but not a receiver. Alternatively, the communication apparatus 1000 can include a receiver but not a transmitter. Whether the communication apparatus 1000 includes a transmitter and a receiver can depend on whether the communication apparatus 1000 performs the sending action and the receiving action in the above-described schemes.

[0361] The above description is only an exemplary description. Details can be referred to the content shown in the above method embodiments. The implementation of each operation in FIG. 9 can also correspond to the description of the corresponding method embodiments shown in FIG. 3 or FIG. 8.

[0362] For example, the communication apparatus 1000 can be used to perform the schemes shown in FIG. 3 or FIG. 8.

[0363] Exemplarily, the communication apparatus 1000 is a first apparatus, and the communication interface 1020 can be used to receive a first reference signal, etc.

[0364] For other implementations, refer to the detailed description of the above embodiments shown in FIG. 3 or FIG. 8. It should be understood that the specific process of each component performing the above corresponding process has been described in detail in the above method embodiments. For brevity, details are not described here.

[0365] FIG. 10 is a schematic block diagram of another communication apparatus 1100 according to an embodiment of the present application. The communication apparatus 1100 can be a first apparatus or a second apparatus, or a chip or a module of the first apparatus or the second apparatus, and is configured to implement the method according to the embodiments shown in FIG. 3 or FIG. 8. Details can be referred to the related description in the above method embodiments.

[0366] The communication apparatus 1100 includes a transceiver unit 1110 and a processing unit 1120. The transceiver unit 1110 is exemplarily described as follows.

[0367] The transceiver unit 1110 can include a sending unit and a receiving unit. The sending unit is configured to perform the sending action of the communication apparatus, and the receiving unit is configured to perform the receiving action of the communication apparatus. For ease of description, the sending unit and the receiving unit are combined into one transceiver unit in the embodiments of the present application. This is uniformly described here, and details are not described hereinafter. The transceiver unit 1110 can implement corresponding communication functions. The transceiver unit 1110 can also be referred to as a communication interface or a communication module.

[0368] The communication apparatus 1100 can comprise a transmitting unit but not a receiving unit. Alternatively, the communication apparatus 1100 can comprise a receiving unit but not a transmitting unit. Specifically, whether the communication apparatus 1100 comprises a transmitting unit or a receiving unit can depend on whether the communication apparatus 1100 performs the transmitting action or the receiving action in the above-described schemes.

[0369] The transceiver unit 1110 can be configured to receive the first reference signal, for example. The processing unit 1120 can be configured to perform the processing, coordinating, etc. involved in the communication apparatus 1100.

[0370] The above description is merely exemplary. The communication apparatus 1100 can be configured to perform the relevant method or steps in the above-described method embodiments.

[0371] Optionally, the communication apparatus 1100 further comprises a storage unit 1130 configured to store programs or codes for performing the above-described methods. Alternatively, the storage unit 1130 can be configured to store instructions and / or data, and the processing unit 1120 can read the instructions and / or data in the storage unit 1130 to enable the communication apparatus 1100 to implement the above-described method embodiments. For example, the communication apparatus 1100 can be configured to perform the schemes shown in FIG. 3 or FIG. 8.

[0372] The transceiver unit 1110 can be configured to receive a first reference signal, for example, the first reference signal being used to determine L1 first phases and L2 first amplitudes, L1 and L2 being positive integers. The processing unit 1120 can be configured to determine a first channel matrix according to the L1 first phases and the L2 first amplitudes, the first channel matrix comprising K first elements, phases of the K first elements being K first phases among the L1 first phases, amplitudes of the K first elements being K first amplitudes among the L2 first amplitudes, K being a positive integer less than or equal to L1 and less than or equal to L2. The processing unit 1120 can be further configured to generate a key according to the first channel matrix.

[0373] For other implementations, refer to the detailed description of the embodiments shown in FIG. 3 or FIG. 8. The specific processes of the components performing the above-described corresponding processes are described in the above-described method embodiments, which are not repeated here for brevity.

[0374] When the communication apparatus 1000 in FIG. 9 is a chip, the communication interface 1020 can be a transceiver, an input / output circuit or a communication interface of the chip. The processor 1010 can be an integrated processor on the chip, or a microprocessor, or an integrated circuit. The transmitting operation of the first apparatus or the second apparatus in the above-described method embodiments can be understood as the output of the chip, and the receiving operation of the first apparatus or the second apparatus in the above-described method embodiments can be understood as the input of the chip.

[0375] When the communication apparatus 1100 in FIG. 10 is a chip, the transceiver unit 1110 can be a transceiver, an input / output circuit or a communication interface of the chip. The processing unit 1120 can be an integrated processor or a microprocessor or an integrated circuit on the chip. The transmitting operation of the first device or the second device in the method embodiments can be understood as the output of the chip, and the receiving operation of the first device or the second device in the method embodiments can be understood as the input of the chip.

[0376] FIG. 11 is an exemplary block diagram of another communication apparatus 10 according to an embodiment of the present application.

[0377] As shown in FIG. 11, the communication apparatus 10 can include, for example, a chip system 110, a memory 120, a bus 130, a power management module 140, a transceiver 150, and the like.

[0378] The chip system 110 can be an integrated circuit chip with signal processing capability. In implementation, each step of the above method can be completed by integrated logic circuits of hardware or instructions in the form of software in the chip system 110.

[0379] By way of example, and without limitation, the chip system 110 can include a circuit or chip responsible for signal processing (such as a modem chip, also known as a baseband chip, or a system on chip (SoC) chip or a system in package (SIP) chip containing a modem core.

[0380] Optionally, a memory (such as a cache) can also be provided in the chip system 110 for storing instructions and data. In some embodiments, the memory in the chip system 110 is a cache memory. The memory can save instructions or data that have just been used or recycled by the chip system 110. If the chip system 110 needs to use the instructions or data again, it can directly call them from the memory. This avoids repeated access and reduces the waiting time of the chip system 110, thus improving the efficiency of the system.

[0381] In some embodiments, the chip system 110 can include one or more interfaces. The interfaces can include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a universal serial bus (USB) interface, etc.

[0382] The memory 120 can include random access memory (RAM) and read-only memory (ROM). The memory 120 can store computer-readable computer-executable code including instructions that, when executed, cause the processor to perform various functions described herein.

[0383] Optionally, the code can include instructions for implementing aspects of the embodiments disclosed herein, for example, including instructions for determining the first parameter. The code can be stored in a non-transitory computer-readable medium, such as system memory or other type of memory. In some cases, the code can not be directly executable by the chip system 110 but can cause a computer (for example, when compiled and executed) to perform functions described herein. In some cases, the memory 120 can include a basic I / O system that can control basic hardware or software operations, such as interaction with peripheral components or devices.

[0384] Illustratively, the chip system 110 performs various functional applications and data processing of the communication device 10 by running instructions stored in the memory 120. For example, when the communication device 10 performs file transmission with other devices (which can also be terminals or network devices), the chip system 110 of the communication device 10 can invoke computer-executable program code stored in the memory 120 to implement the communication method provided by the embodiments of the present application.

[0385] In addition, the memory 120 can be integrated in the above-mentioned chip system 110, or independent of the chip system 110.

[0386] Exemplarily, the bus 130 can be a USB, used to support mutual communication between various parts in the communication device 10.

[0387] The power management module 140 is used to receive charging input from a charger. Optionally, the power management module 140 can supply power to the communication device 10 (e.g., a battery module of the communication device 10) while charging the communication device 10. As an example but not limitation, the power management module 140 can also supply power to devices other than the communication device 10.

[0388] The transceiver 150 can communicate bi-directionally with one or more antennas, wired or wireless links, for example, the transceiver 150 can represent a wireless transceiver and can communicate bi-directionally with another wireless transceiver. The transceiver 150 can also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. Where the transceiver 150 includes a modem, the modem can be implemented as a baseband processor.

[0389] In some cases, a wireless device can include a single antenna. However, in some cases the device can have more than one antenna, like the antenna 1 and the antenna 2 shown in FIG. 11, which can be capable of concurrently transmitting or receiving multiple wireless transmissions. Exemplarily, the antenna 1 and the antenna 2 are used to emit and receive electromagnetic wave signals. Each antenna in the communication device 10 can be used to cover a single or multiple communication frequency bands. Different antennas can also be multiplexed to improve the utilization of the antennas. For example: the antenna 1 can be multiplexed as a diversity antenna of a wireless local area network. In some other embodiments, the antennas can be used in combination with a tuning switch. The communication device 10 can transmit files to other devices through a wireless communication function.

[0390] In one design, the communication device 10 can correspond to the first device in the above-mentioned method embodiments.

[0391] The device 10 can implement steps or processes corresponding to the steps performed by the first device in the above-mentioned method embodiments, wherein the transceiver 150 can be used to perform transceiver-related operations of the first device in the above-mentioned method embodiments, for example, perform step S310 in the above-mentioned method embodiments; the chip system 110 can be used to perform processing-related operations of the first device in the above-mentioned method embodiments, for example, perform step S330 in the above-mentioned method embodiments.

[0392] In some possible implementations, the communication apparatus 10 can be a terminal device. For example, the communication apparatus 10 can include a short-range communication module 164, a sensor 161, a display 162, or a camera 163, as shown in FIG. 11.

[0393] For example, the short-range communication module 164 can include a module supporting short-range communication, such as WiFi, Bluetooth, and the like.

[0394] For example, the sensor 161 can include a pressure sensor, a gyroscope sensor, a barometric pressure sensor, a magnetic sensor, an acceleration sensor, a distance sensor, a proximity light sensor, a fingerprint sensor, a temperature sensor, a touch sensor, an ambient light sensor, a bone conduction sensor, and the like.

[0395] For example, the display 162 is configured to display images, videos, and the like. The display includes a display panel. The display panel can be a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode (AMOLED), a flex light-emitting diode (FLED), a mini light-emitting diode (LED), a Micro LED, a Micro OLED, a quantum dot light emitting diode (QLED), or the like. For example, in an embodiment of the present application, the display can be configured to display an interface required to be displayed by the communication apparatus 10. For example, the communication apparatus 10 can implement the display function by a graphics processing unit (GPU), the display, and an application processor, or the like. The GPU is a microprocessor for image processing, connected to the display and the application processor. The GPU is configured to perform mathematical and geometric calculations for graphics rendering. The chip system 110 can include one or more GPUs, which execute program instructions to generate or change display information.

[0396] For example, the camera 163 is configured to acquire images, videos, and the like.

[0397] It can be understood that the structure shown in FIG. 11 does not constitute a specific limitation on the communication apparatus 10, and the specific structure of the terminal device and / or the network device can refer to that shown in FIG. 11. In some embodiments, the communication apparatus 10 can also include more or fewer components than those shown in FIG. 11, or combine some components, or split some components, or different component arrangements, etc. Alternatively, some components shown in FIG. 11 can be implemented in hardware, software, or a combination of software and hardware, and the terminal device and / or the network device can be added or reduced components based on the structure given in FIG. 11.

[0398] FIG. 12 is a schematic block diagram of still another communication apparatus 20 according to an embodiment of the present application.

[0399] As shown in FIG. 12, the communication apparatus 20 can include a baseband unit 210, which can communicate with external devices through a cellular radio frequency (RF) transceiver 220 (e.g., if the communication apparatus 20 is a terminal device, the baseband unit 210 can communicate with network devices or terminal devices through the cellular RF transceiver 220; also e.g., if the communication apparatus 20 is a network device, the baseband unit 210 can communicate with terminal devices and / or core network devices through the cellular RF transceiver 220).

[0400] By way of example, the baseband unit 210 can include a computer- readable medium / memory. The baseband unit 210 can be responsible for the general processing of the application including the execution of software stored on the computer-readable medium / memory. The software, when executed by the baseband unit 210, causes the baseband unit 210 to perform the various functions described supra. The computer-readable medium / memory can also be used for storing data that is manipulated by the baseband unit 210 when executing software.

[0401] Optionally, the baseband unit 210 further includes a receiving unit 201, a management unit 202, and a sending unit 203. The management unit 202 includes one or more sub-units shown in FIG. 12 (e.g., a channel matrix reconstruction sub-unit and a key generation sub-unit), wherein the channel matrix reconstruction sub-unit can be used for the operation of determining the first channel matrix or the second channel matrix in the above method embodiments, and the key generation sub-unit can be used for the operation of generating the key in the above method embodiments. The units in the management unit 201 can be stored in the computer-readable medium / memory and / or configured as hardware in the baseband unit 210. Among them, the receiving unit 201 and the sending unit 203 can be referred to as a transceiving unit.

[0402] When the communication apparatus 20 is used to implement the functions of the first device in the above method embodiments, the receiving unit 201 is configured to perform the receiving steps of the first device, the sending unit 203 is configured to perform the sending steps of the first device, and the management unit 202 is configured to perform the processing steps of the first device.

[0403] Exemplarily, when the communication apparatus 20 is configured to implement the functions of the first device in the above-mentioned method embodiments, the receiving unit 201 is configured to receive a first reference signal, the first reference signal being used to determine L1 first phases and L2 first amplitudes, L1 and L2 being positive integers; the management unit 202 is configured to determine a first channel matrix according to the L1 first phases and the L2 first amplitudes, the first channel matrix comprising K first elements, phases of the K first elements being K first phases among the L1 first phases, amplitudes of the K first elements being K first amplitudes among the L2 first amplitudes, K being a positive integer less than or equal to L1 and less than or equal to L2; and the management unit 202 is further configured to generate a key according to the first channel matrix.

[0404] For example, when the apparatus 20 is configured to execute the method in FIG. 3 or FIG. 8, the receiving unit 201 can be configured to execute the step of receiving information in the method; the management unit 202 can be configured to execute the processing steps in the method; and the sending unit 203 can be configured to execute the step of sending information in the method.

[0405] For more details of the receiving unit 201, the management unit 202 and the sending unit 203, please refer to the above-mentioned descriptions in the method embodiments, which will not be repeated here.

[0406] The present application further provides a chip comprising a processor, which is configured to invoke and run instructions stored in a memory, so that a communication apparatus installed with the chip executes the method in any of the above-mentioned examples.

[0407] The present application further provides another chip comprising an input interface, an output interface and a processor, which are connected through internal connection paths, and the processor is configured to execute codes in a memory, and when the codes are executed, the processor is configured to execute the method in any of the above-mentioned examples. Optionally, the chip further comprises a memory configured to store computer programs or codes.

[0408] The present application further provides a processor configured to be coupled with a memory, and configured to execute the method and functions of the communication apparatus in any of the above-mentioned embodiments.

[0409] In another embodiment of the present application, a computer program product comprising computer programs or instructions is provided, and when the computer program product is run on a computer, the method in the above-mentioned embodiments is implemented.

[0410] The present application further provides a computer program, and when the computer program is run on a computer, the method in the above-mentioned embodiments is implemented.

[0411] In another embodiment of the present application, a computer readable storage medium is provided, which stores a computer program. The computer program is executed by a computer to implement the method in the foregoing embodiments.

[0412] The present application also provides a communication system, which comprises a first device and a second device. The first device and the second device are configured to perform the method performed by the first device and the second device in the foregoing embodiments, respectively.

[0413] Those skilled in the art can understand that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solutions. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0414] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0415] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0416] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0417] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0418] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the parts that contribute to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0419] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A communication method characterized by comprising: The method comprises: receiving a first reference signal, the first reference signal being used to determine L1 first phases and L2 first amplitudes, L1 and L2 being positive integers; determining a first channel matrix according to the L1 first phases and the L2 first amplitudes, the first channel matrix comprising K first elements, phases of the K first elements being K first phases in the L1 first phases respectively, amplitudes of the K first elements being K first amplitudes in the L2 first amplitudes respectively, K being a positive integer less than or equal to L1 and less than or equal to L2; generating a key according to the first channel matrix.

2. The method of claim 1, wherein, The determining the first channel matrix according to the L1 first phases and the L2 first amplitudes comprises: determining the first channel matrix according to a first index, a second index, the L1 first phases and the L2 first amplitudes, wherein the first index is an index of the K first phases, and the second index is an index of the K first amplitudes.

3. The method of claim 2, wherein: the first index is an index of K second phases, positions of the K second phases in L1 second phases being same as positions of the K first phases in the L1 first phases; and wherein: an average uplink-downlink difference of the K second phases is less than or equal to a first threshold value, and / or an average correlation coefficient of the K second phases is less than or equal to a second threshold value, the average uplink-downlink difference of the K second phases being determined according to the K second phases and K third phases in L1 third phases, positions of the K third phases in the L1 third phases being same as positions of the K first phases in the L1 first phases; wherein the K second phases are determined according to an uplink reference signal, or the K third phases are determined according to a downlink reference signal.

4. The method of claim 2 or 3, wherein: the second index is an index of K second amplitudes, positions of the K second amplitudes in L2 second amplitudes being same as positions of the K first amplitudes in the L2 first amplitudes; and wherein: an average uplink-downlink difference of the K second amplitudes is less than or equal to a third threshold value, and / or an average correlation coefficient of the K second amplitudes is less than or equal to a fourth threshold value, the average uplink-downlink difference of the K second amplitudes being determined according to the K second amplitudes and K third amplitudes in L2 third amplitudes, positions of the K third amplitudes in the L2 third amplitudes being same as positions of the K first amplitudes in the L2 first amplitudes; wherein the K second amplitudes are determined according to an uplink reference signal, or the K third amplitudes are determined according to a downlink reference signal.

5. The method according to any one of claims 1 to 4, characterized in that, The generating the key according to the first channel matrix comprises: determining, according to the first channel matrix, a second channel matrix, the second channel matrix comprising K second elements, phases of the K second elements being a sum of the K first phases and a first parameter; generating the key according to the second channel matrix.

6. The method of claim 5, wherein, The first parameter is predefined or preconfigured; or The method further comprises: receiving or sending first information, the first information being used for indicating the first parameter.

7. The method of claim 5, wherein, The initial phase of the first reference signal is determined according to a second parameter, and / or The method further comprises: sending a second reference signal, an initial phase of the second reference signal being determined according to the first parameter.

8. The method according to any one of claims 1 to 7, characterized in that, The key is determined according to a third parameter and a quantization threshold, wherein the third parameter is a spectral norm of the first channel matrix or a spectral norm of a second channel matrix, the second channel matrix comprising K second elements, phases of the K second elements being a sum of the L1 first phases and a first parameter; wherein The quantization threshold is determined according to K.

9. The method of claim 8, wherein, The quantization threshold is 2σ e K 1 / 4 , wherein σ e is the maximum standard deviation of the average up-down line difference of the K first elements or the maximum standard deviation of the average up-down line difference of the K second elements, the phase of the K second elements being the sum of the L1 first phases and a first parameter, wherein the average up-down line difference of the K first elements is determined according to K second phases, K third phases, K second amplitudes and K third amplitudes, and the average up-down line difference of the K second elements is determined according to the K second phases, the K third phases, the K second amplitudes, the K third amplitudes and the first parameter; wherein, The K second phases are determined according to uplink reference signals, and the K third phases are determined according to downlink reference signals, or the K second phases are determined according to downlink reference signals, and the K third phases are determined according to uplink reference signals. The K second amplitudes are determined according to uplink reference signals, and the K third amplitudes are determined according to downlink reference signals, or the K second amplitudes are determined according to downlink reference signals, and the K third amplitudes are determined according to uplink reference signals.

10. The method according to any one of claims 1 to 9, characterized in that, The L1 first phases comprise L1’ fourth phases and L1” fifth phases, L1’ and L1” being positive integers less than L1, One of the L1’ fourth phases is a difference between a receiving initial phase of a first antenna and a receiving initial phase of a second antenna, wherein the key is used for encrypting information sent through the first antenna, and the key is used for encrypting information sent through the second antenna; or One of the L1” fifth phases is a difference between a sending initial phase of a first antenna and a sending initial phase of a second antenna, wherein the key is used for decrypting information sent through the first antenna, and the key is used for decrypting information sent through the second antenna.

11. A communications device, characterized by The apparatus comprises at least one module or at least one unit for performing the method of any of claims 1 to 10.

12. A communications device, characterized by The apparatus comprises: at least one processor configured to cause the method of any of claims 1 to 10 to be performed by executing computer programs or instructions.

13. The communication apparatus according to claim 12, wherein The apparatus further comprises a memory configured to store the computer programs or the instructions.

14. A computer-readable storage medium, characterized in that, The computer readable storage medium has stored thereon computer programs or instructions which, when executed, cause the method of any of claims 1 to 10 to be performed. The computer readable storage medium has stored thereon computer programs or instructions which, when executed, cause the method of any of claims 1 to 10 to be performed.

15. A computer program product, characterised in that, comprising computer programs or instructions, which, when executed, implement the method of any of claims 1 to 10.

16. A communications device, characterized by comprising a processor for causing the communication device to perform the method of any of claims 1 to 10 by executing computer programs stored in a memory and / or by logic circuitry.

17. The communication apparatus according to claim 16, wherein further comprising a communication interface for the communication device to communicate with other devices.

18. The communication apparatus according to claim 16 or 17, wherein, further comprising the memory.

19. The communication apparatus according to any one of claims 16-18, wherein, the communication device is a chip or chip system.

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