Spectrum sharing method for cognitive satellite networks based on blockchain smart contract verification

Abstract

The present application discloses a cognitive satellite network spectrum sharing method based on blockchain smart contract verification. The present application is applied to a cognitive dual-satellite network system, which includes: a master satellite and a slave satellite; wherein the master satellite and the slave satellite cover the same area; the method steps include: sending a spectrum lease frame through a terminal of the master satellite; receiving and parsing the spectrum lease frame at a terminal of the slave satellite to obtain a spectrum band that can be leased; and sending a corresponding spectrum request frame according to the spectrum lease frame; the terminal of the master satellite receives and parses the spectrum request frame to obtain a spectrum band requested for lease and a corresponding lease fee; matching the spectrum band that can be leased with the spectrum band requested for lease to obtain a matching result; according to the matching result, selecting the highest lease fee, allocating the spectrum band that can be leased to the corresponding terminal of the slave satellite and generating a block; sending the block to the blockchain network for verification to complete the cognitive satellite network spectrum sharing.

Description

Technical Field

[0001] The present application relates to the field of cognitive satellite network technology, and specifically to a cognitive satellite network spectrum sharing method based on blockchain smart contract verification. Background Art

[0002] The rapid expansion of wireless Internet services has led to an exponential growth in the number of users of wireless communication systems. This rapid growth requires more spectrum and continuous bandwidth. Current spectrum management lacks flexibility. In order to meet the growing demand for spectrum, new regulatory methods and technical means are needed for spectrum allocation, utilization and management to achieve more flexible spectrum sharing and dynamic spectrum access to meet the growing spectrum crisis.

[0003] Dynamic spectrum access is an effective way to achieve spectrum sharing and can achieve effective use of spectrum resources. Cognitive radio technology improves the efficiency of spectrum utilization. In cognitive radio technology, the primary user, i.e., the spectrum authorized user, and the secondary user, i.e., the spectrum unauthorized user, learn the spectrum usage of the primary user through spectrum sensing technology, thereby determining the spectrum that is not used by the primary user. This type of spectrum is called spectrum loophole. Although cognitive radio technology improves the efficiency of spectrum utilization, there is no good solution mechanism for spectrum access security issues. In addition, cognitive wireless systems also require additional spectrum sensing function modules. Summary of the invention

[0004] This application abandons the additional spectrum sensing module by sharing the spectrum between the terminals of the main satellite and the terminals of the slave satellite; at the same time, it realizes safe spectrum access, which not only maximizes the utilization of the spectrum, but also solves the security problem of dynamic spectrum access.

[0005] To achieve the above-mentioned purpose, the present application provides a cognitive satellite network spectrum sharing method based on blockchain smart contract verification, which is applied to a cognitive dual-satellite network system, wherein the cognitive dual-satellite network system comprises: a master satellite and a slave satellite; wherein the master satellite and the slave satellite cover the same area, the terminal of the master satellite is called a master user node, and the terminal of the slave satellite is called a slave user node; the master user node and the slave user node form a blockchain network through a known public control channel; the method steps comprise:

[0006] Sending a spectrum lease frame through a terminal of the primary satellite;

[0007] The terminal from the satellite receives and parses the spectrum lease frame to obtain a spectrum band that can be leased; and sends a corresponding spectrum request frame according to the spectrum lease frame;

[0008] The terminal of the main satellite receives and parses the spectrum request frame to obtain the spectrum band requested for leasing and the corresponding leasing fee;

[0009] Matching the leaseable spectrum band with the spectrum band requested for lease to obtain a matching result;

[0010] According to the matching result, the highest lease fee is selected, the leaseable spectrum band is allocated to the corresponding terminal of the slave satellite and a block is generated;

[0011] The block is sent to the blockchain network for verification to complete the cognitive satellite network spectrum sharing.

[0012] Preferably, the spectrum leasing frame includes: a first frame preamble, a first frame type and a first information field; wherein the first information field includes: the leasable spectrum band, lease time, usage area and minimum lease fee; and the first frame type is the spectrum leasing frame.

[0013] Preferably, the spectrum band requested for leasing includes: a second frame preamble, a second frame type and a second information field; the second information field includes: the spectrum band requested for leasing and spectrum electronic coins; the second frame type is the spectrum request frame.

[0014] Preferably, the block includes: blockchain header information, leased spectrum band, lease time, usage area, slave user node information and lease transaction information.

[0015] Preferably, the method for obtaining the leaseable spectrum band includes: obtaining the leaseable spectrum band by sensing all spectrum wireless resource blocks of the master satellite through the terminal of the slave satellite; wherein the leaseable spectrum band constitutes a target spectrum loophole.

[0016] Preferably, the method for sending the corresponding spectrum request frame includes:

[0017] Calculating the occupancy rate of all spectrum wireless resource blocks occupied by the main satellite;

[0018] Obtaining a probability that the target spectrum hole is not occupied by the primary satellite based on the target spectrum hole and the occupancy rate;

[0019] Determining expected data transmission and switching time corresponding to the target spectrum hole according to the probability;

[0020] Determine the target spectrum hole according to the expected data transmission and switching time of all spectrum holes;

[0021] The corresponding spectrum request frame is generated according to the spectrum leasing frame corresponding to the target spectrum hole.

[0022] Preferably, the method for determining the probability comprises:

[0023] Determine the information transmission rate of the spectrum hole according to the signal-to-noise ratio of the terminal of the slave satellite, the number of spectrum wireless resource blocks in the target spectrum hole, and the spectrum of the spectrum wireless resource blocks;

[0024] Determine a corresponding transmission time according to the amount of data requested to be transmitted by the terminal of the slave satellite and the information transmission rate;

[0025] The probability is determined according to the occupancy rate, the transmission time and the number of spectrum radio resource blocks.

[0026] Preferably, the method for determining the expected data transmission and switching time includes: obtaining the expected data transmission and switching time according to the probability, the information transmission rate, the delay time of spectrum migration and the delay time of spectrum switching.

[0027] Preferably, the target spectrum hole is the smallest spectrum hole corresponding to the expected data transmission and switching time among all the spectrum holes.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This application realizes spectrum sharing between the terminals of the main satellite and the terminals of the slave satellite, without the need for an additional spectrum sensing module, and realizes secure access to the spectrum. When the spectrum owned by the terminals of the main satellite is not used at a specific time and area, the terminals of the slave satellite can rent these spectrums, thereby improving the efficiency of spectrum utilization and generating additional revenue for the terminals of the main satellite. Therefore, this technical solution not only realizes the maximum utilization of the spectrum, but also solves the security problem of dynamic spectrum access. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solution of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 This is a schematic diagram of the structure of the cognitive satellite network system used in this application;

[0032] Figure 2 This is a schematic diagram of the scenario in which this application is applied to a blockchain network;

[0033] Figure 3 It is a schematic diagram of the terminal function block from the satellite;

[0034] Figure 4 Schematic diagram of the frame structure of the SLRA frame;

[0035] Figure 5 A schematic diagram of the spectrum sharing method of the cognitive satellite network system of this application;

[0036] Figure 6 A schematic flow chart of the steps of sending a spectrum request frame corresponding to the spectrum lease frame;

[0037] Figure 7 A schematic flow chart of the steps for determining the probability that the spectrum hole is not occupied by the primary satellite;

[0038] Figure 8 A schematic diagram of a spectrum sharing system for a cognitive satellite network system. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0041] In a cognitive wireless network system, as the working state of the terminal of the main satellite changes, the spectrum used by the terminal of the main satellite also changes, that is, the spectrum loophole is constantly changing. When the terminal of the slave satellite accesses the spectrum, it must take into account that the spectrum used by the terminal of the main satellite will change. The cognitive satellite network system needs to strictly obey the master / slave relationship, reduce interference to the terminal of the main satellite, and ensure the security of spectrum access. When the terminal of the main satellite is authorized to use the spectrum, the terminal of the slave satellite must immediately exit the spectrum and use other idle spectrum. Idle spectrum is spectrum loophole. This requires considering effective spectrum management and spectrum transfer schemes in spectrum sharing and coordinating spectrum sharing. This application proposes a spectrum sharing scheme for a cognitive satellite network system based on blockchain verification. The scheme discloses a media access control protocol based on blockchain verification, realizes spectrum sharing between the terminal of the main satellite and the terminal of the slave satellite, does not require an additional spectrum sensing module, and realizes secure access to the spectrum at the same time. When the spectrum of the terminal of the main satellite is not used at a specific time and area, the terminal of the slave satellite can rent these spectrums, thereby improving the efficiency of spectrum utilization and generating additional income for the terminal of the main satellite. Ultimately, not only is spectrum utilization maximized, but the security issues of dynamic spectrum access are also resolved.

[0042] like Figure 1 As shown, it is a schematic diagram of the structure of the cognitive satellite network system of the present application. The cognitive satellite network system consists of two types of satellites, master and slave. Each satellite is a GEO multi-beam broadband satellite, which is a multi-beam satellite covering the same area and operates in normal forward mode. The two satellites are connected to different gateways on the ground, namely Gateway 1 and Gateway 2. These gateways are connected through the ground backbone network and are connected to the network management center and satellite control center on the ground. In the cognitive satellite network system, one is defined as the master satellite and the other is defined as a slave satellite. The terminal of the slave satellite is equipped with a cognitive radio module SDR.

[0043] like Figure 2 As shown, it is a schematic diagram of the scenario in which the present application is applied to the blockchain network. The blockchain network consists of the terminals of the main satellite and the terminals of the slave satellite. The terminals of the main satellite are spectrum licensed network user nodes, and the terminals of the slave satellite are spectrum unlicensed network user nodes. When the terminal spectrum of the main satellite is not used at a specific time and area, the terminals of the slave satellite can rent these spectrums, thereby improving the spectrum utilization efficiency and generating additional income for the terminals of the main satellite. Among them, the terminal of the main satellite is called the main user node, and the terminal of the slave satellite is called the slave satellite node.

[0044] exist Figure 2 In the blockchain network shown, it is assumed that there are N wireless network nodes. The users in the coverage area are divided into terminals of the main satellite, represented by PU; terminals of the slave satellite, represented by SU. The terminals of the slave satellite users are equipped with cognitive radio modules SDR, which opportunistically access the spectrum not used by the main satellite users. Among them, there are P terminals PU of the main satellite 1 , PU 2 , ..., PU p , S slave satellite terminals SU p+1 ,SU p+2 ,...,SU p+s, these terminals are equipped with duplex transceivers, and duplex transmitters can send or receive at any time on the wireless channel. In the cognitive satellite network system, there is a central access point to manage the uplink and downlink channels and user data. The spectrum is divided into M orthogonal channels, which are symmetrical. Among them, M takes the value of 1, 2, ..., m. All terminals have a common control channel that can be used to exchange control messages between the terminals of the master satellite and the terminals of the slave satellite. This control channel runs a spectrum management control frame, which is defined as an SLRA frame. The SLRA frame is used for spectrum leasing, spectrum request, and spectrum allocation of nodes. In the cognitive satellite network system, as the working state of the master satellite changes, the spectrum used by the master satellite also changes, that is, the spectrum loophole is constantly changing. When the terminal of the slave satellite accesses the spectrum, it must take into account the change of the spectrum used by the master satellite. The cognitive satellite network system needs to strictly obey the master / slave relationship to reduce interference with the master satellite. When the master satellite is authorized to use the spectrum, the slave satellite must immediately exit the spectrum and use other idle spectrum. Idle spectrum is spectrum loophole. This requires considering effective spectrum management and spectrum migration schemes in spectrum sharing and coordinating spectrum sharing. The present application discloses a spectrum adjustment scheme for a terminal of a slave satellite in a cognitive satellite network system. The basic idea is that the terminal of the slave satellite predicts the probability of the main satellite recovering resources by observing the spectrum occupancy rate. After the terminal of the slave satellite obtains the available spectrum holes through spectrum sensing, it is necessary to calculate the expected transmission time when selecting a spectrum from the numerous spectrum holes, and perform spectrum migration through a switching program. By selecting a spectrum based on the shortest expected transmission time, the defect of the current high-level spectrum management mechanism of cognitive radio for spectrum hole selection, which generally uses the maximum idle time scheme, is overcome, so that the probability of spectrum migration is reduced in the cognitive satellite network system as a whole, thereby achieving the purpose of improving system performance.

[0045] In the cognitive satellite network system, the terminal of the master satellite uses SLRA frames to publish the idle spectrum that can be leased, and the terminal of the slave satellite uses SLRA frames to request the available spectrum. The terminal of the master satellite then allocates the idle spectrum that can be leased to the terminal of the slave satellite. The terminal requires system clock synchronization, which is achieved through a GPS receiver. A blockchain network is established on this control channel, which records the GPS information, spectrum usage information, and spectrum leasing information of each node.

[0046] like Figure 3 The figure shows a functional block diagram of a terminal from a satellite. The terminal from the satellite includes a cognitive radio module SDR, MAC, a network layer, a transport layer, and an application layer. Among them, the spectrum adjustment scheme implemented by the terminal from the satellite involves the cognitive radio module SDR, the MAC layer, and the network layer, and realizes spectrum perception, spectrum analysis, spectrum decision, and spectrum adjustment.

[0047] The core technology of cognitive radio is spectrum sensing. The purpose of spectrum sensing is to find spectrum loopholes. The terminals of the satellites use the spectrum loopholes to transmit information, while not causing harmful interference to the terminals of the main satellites. When the terminals of the satellites use the spectrum loopholes for communication, they must be able to quickly sense that the terminals of the main satellites need to use the spectrum, and switch the spectrum in time to release the occupied spectrum for the main satellites to use. The specific working process of the terminals of the satellites is as follows: In each specific time slot, the antenna receives the signal, transmits it to the broadband RF front end, decides on the available channel, and transmits the information to the MAC layer through the available channel. The specific implementation can be achieved by energy detection and selecting one from multiple candidate available channels, identifying the type of signal received in the candidate available channel, and if a signal is found in the corresponding candidate available channel, the MAC layer will select another candidate available channel and continue to detect this candidate available channel until an unoccupied candidate available channel is found.

[0048] The master satellite operates under a larger main beam, while the slave satellite has a smaller beam in the same coverage area. For the larger main beam, there is a coverage area with many spot beams within each main beam, and these spot beams belong to the slave satellite. The beam selection mode and timing information of the master satellite are shared to the slave satellite to realize the cognitive function. Based on the prior knowledge of the beam selection mode, the terminal beam selection mode of the slave satellite is designed so that it does not affect the terminal operation of the master satellite. In addition, the master satellite transmission and the slave satellite transmission can be synchronized by timing information. The slave satellite needs to be more flexible and equipped with a smaller transponder.

[0049] like Figure 4 As shown, it is a schematic diagram of the frame structure of the SLRA frame. The SLRA frame includes three fields: frame preamble, frame type, and information field. Among them, the first field is the frame preamble, which is used to synchronize the transmitter clock of the terminal of the main satellite and the receiver clock of the terminal of the slave satellite. The second field is the frame type, which includes two types, one is the spectrum lease frame announced by the terminal of the main satellite, and the other is the spectrum request frame sent by the terminal of the slave satellite. The third field is the information field. When the frame type is a spectrum lease frame announced by the terminal of the main satellite, at this time, the information field includes but is not limited to the frequency band, time, region, minimum lease fee and other information of the leaseable spectrum. When the frame type is a spectrum request frame sent by the terminal of the slave satellite, the information field includes but is not limited to the frequency band of the leaseable spectrum and the supported lease fee. Among them, the lease fee is expressed in spectrum electronic coins.

[0050] In actual use, in a blockchain network composed of terminals of the main satellite and the slave satellite, the terminal of the main satellite sends SLRA frames according to its own spectrum usage status, and publishes the time and area where the spectrum can be leased. At this time, the frame type in the SLRA frame is the spectrum lease frame announced by the terminal of the main satellite. The information field in the SLRA frame includes but is not limited to the frequency band, time, and area. The terminal of the slave satellite obtains spectrum access opportunities by sending SLRA frames. At this time, the frame type in the SLRA frame is a spectrum request frame sent by the terminal of the slave satellite. The information field in the SLRA frame includes but is not limited to the frequency band of the spectrum that can be leased and the supported leasing fees.

[0051] like Figure 5 The figure shows a schematic diagram of the method flow of the present technical solution. The steps include:

[0052] S501. The main satellite terminal sends a spectrum lease frame;

[0053] S502. Receive a spectrum lease frame from a satellite terminal, parse the spectrum lease frame, obtain a spectrum band that can be leased; and send a corresponding spectrum request frame according to the spectrum lease frame;

[0054] S503. The terminal of the master satellite receives the spectrum request frame from the terminal of the slave satellite, parses the spectrum request frame, obtains the spectrum band requested for leasing and the corresponding leasing fee; matches the leasable spectrum band with the spectrum band requested for leasing, and if the match is successful, selects the highest leasing fee, allocates the leasable spectrum band to the corresponding terminal of the slave satellite, generates blocks at the same time, and sends the blocks to the blockchain network for verification.

[0055] Blockchain is a new decentralized protocol that can safely store transaction data, information cannot be forged or tampered with, and can flexibly publish and execute smart contracts without the need for review by any centralized organization. Transactions can be either digital currency or digital assets. Blockchain technology solves the Byzantine Generals Problem, greatly reduces the trust cost and accounting cost of the real economy, and redefines the property rights system in the Internet era. In the existing blockchain technology, the nodes used are integrated with business logic processing and data storage. The user's business logic processing service is published on the verification node (VP) of the blockchain, similar to the programmable code (CC) of the smart contract. Each CC corresponds to a unique ID. When the client wants to perform an operation, it must obtain this unique ID (identification). And when the account is settled on the blockchain, this unique ID will also be used as the key to save the results of all business logic processing of this CC.

[0056] In this embodiment, this mechanism design eliminates an additional sensing cycle overhead of the traditional cognitive radio network. When the terminal of the main satellite has idle spectrum, the spectrum leasing information is published through the SLRA frame. The terminal of the slave satellite receives the spectrum leasing information and sends a spectrum request frame. The terminal of the main satellite receives the spectrum request frame sent by the terminal of the slave satellite, allocates available idle spectrum to the terminal of the slave satellite, and conducts a leasing transaction. In order to realize spectrum leasing and allocation based on the blockchain protocol, spectrum electronic coins are introduced. The terminal of the main satellite publishes idle spectrum, and there is a minimum leasing fee based on spectrum electronic coins in the SLRA frame. When the terminal of the slave satellite sends a spectrum request frame, the corresponding leasing fee is configured in the SLRA frame. In addition, when the terminal of the slave satellite requests to lease spectrum, the leasing fee must be higher than the minimum leasing fee of the terminal of the main satellite. Within a certain time interval, if multiple spectrum request frames from the terminals of the slave satellite are received, the terminal of the main satellite allocates spectrum to the slave user node with the highest leasing fee, and the transaction is settled in spectrum electronic coins. The terminal of the main satellite collects the spectrum electronic coins obtained by the transaction by updating the blockchain.

[0057] When the cognitive satellite network system is actually deployed, the central access point manages the exchange of spectrum electronic coins with actual real money, that is, spectrum electronic coins can be purchased with real money, so that spectrum electronic coins can be directly exchanged with real money at the terminal of the slave satellite. The terminal of the slave satellite leases the available spectrum from the terminal of the main satellite through the blockchain verification protocol. At the same time, when the terminal of the slave satellite does not have enough spectrum electronic coins, it can exchange spectrum electronic coins with real money to obtain available spectrum from the terminal of the main satellite. The blockchain records all transactions. In addition to the basic blockchain header information, the block also includes leased spectrum information, lease time, usage area, terminal information of the slave satellite, and lease transaction information.

[0058] For the spectrum request frame, based on the spectrum occupancy rate, the probability of the main satellite recovering resources is predicted. After the satellite terminal obtains the available spectrum holes through spectrum sensing, it is necessary to calculate the expected transmission time corresponding to each spectrum hole when selecting a spectrum from the many spectrum holes, select the target spectrum hole according to the expectation, and perform spectrum migration to the corresponding target spectrum hole through the switching procedure. In this embodiment, by calculating the shortest expected transmission time when selecting a spectrum, the cognitive satellite network system as a whole reduces the probability of spectrum migration, thereby achieving the purpose of improving system performance.

[0059] In this embodiment, H i represents the i-th spectrum hole detected from the satellite, i.e., idle spectrum or spectrum hole. i It is composed of some adjacent radio resource blocks RB.

[0060] Assume that the terminal SU from the satellite has data services to transmit, using TE (H i ) represents the expected transmission and switching time of the spectrum hole Hi of the terminal SU data service from the satellite. E (H i ) value, the longer the expected transmission and switching time is, and the longer the satellite terminal SU is in using the spectrum loophole H i When transmitting data, the probability that resources are recovered by the terminal PU of the main satellite is high. This will lead to spectrum migration and switching operations. E (H i ) value is smaller, the success rate of the terminal SU of the slave satellite using the spectrum hole Hi to transmit data is higher, because the probability of the spectrum hole Hi resource being recovered by the terminal PU of the master satellite is low. The step of sending the corresponding spectrum request frame by the spectrum leasing frame is implemented as follows Figure 6 As shown, including:

[0061] S601. The terminal of the slave satellite senses all spectrum wireless resource blocks of the main satellite, obtains spectrum bands that can be leased, and the spectrum bands that can be leased constitute spectrum loopholes; and obtains the occupancy rate of the spectrum wireless resource blocks occupied by the main satellite.

[0062] In S601, the terminal of the satellite uses a cognitive radio module SDR to observe the signal power and the usage status of the spectrum wireless resource block RB to obtain the utilization rate and spectrum hole of the spectrum wireless resource block. In further detail, the terminal SU of the satellite periodically senses the spectrum of each spectrum wireless resource block to obtain the occupancy rate of each spectrum wireless resource block. j It is composed of some adjacent spectrum radio resource blocks RB. Assume N k It is the spectrum radio resource block RB within a period of time k The cumulative number of PUs occupied by the main satellite. If a spectrum radio resource block RB is used once within a time period k , then N k The value of will increase by 1. If N k The larger the value, the more frequently the terminal PU of the main satellite occupies the spectrum wireless resource block RBk, which also means that the terminal SU of the slave satellite uses the spectrum wireless resource block RBk. k Otherwise, if N k The smaller the value of is, the higher the chance that the terminal SU from the satellite will use the spectrum radio resource block RB. k , so the probability that the terminal PU of the main satellite interrupts the transmission of data from the terminal SU of the satellite is lower. Observe and record all spectrum radio resource blocks RB over a period of time k Occupancy information. j These are some adjacent spectrum radio resource blocks RB k, forming a spectrum hole. Similarly, a series of spectrum holes (H 1 , H 2 , …, H j …, H R ).

[0063] S602. The terminal of the slave satellite determines the probability that the spectrum hole is not occupied by the master satellite according to the occupancy rate.

[0064] According to the relative position of the terminal SU from the satellite, the spectrum hole H is calculated using i Expected execution time for data transfer T E (H i If the terminal SU of the satellite detects the presence of the terminal PU of the main satellite, the spectrum resources are released and frequency migration and switching are performed.

[0065] like Figure 7 As shown, it is a schematic diagram of the process of determining the probability that the spectrum hole is not occupied by the main satellite, and the steps include:

[0066] S602.1. Determine the information transmission rate of the spectrum hole according to the signal-to-noise ratio of the terminal from the satellite, the number of spectrum wireless resource blocks in the spectrum hole, and the spectrum of the spectrum wireless resource block.

[0067] The signal-to-noise ratio from the satellite terminal is defined as SNR. i , let R i Indicates that for the spectrum hole H i If the spectrum hole H i Contains m i spectrum radio resource blocks RB, then there are

[0068] R i =m i ×RB×log 2 (1+SNR) (1)

[0069] S602.2. Determine the corresponding transmission time according to the amount of data transmitted by the satellite terminal and the information transmission rate of the spectrum hole.

[0070] In S602.2, the size D of the data requested to be transmitted by the terminal SU from the satellite is estimated. t The required transmission time t req , based on formula (1), we can obtain the spectrum hole H i The transmission rate R i get.

[0071] Then there is

[0072]

[0073] S602.3. Determine the probability that the spectrum hole is not occupied by the main satellite according to the occupancy rate of the spectrum wireless resource block occupied by the main satellite, the transmission time, and the number of spectrum wireless resource blocks in the spectrum hole.

[0074] Assumption: P(H i , t req ) indicates that at t req Spectrum hole H in the time period i The probability of terminal PU being not occupied by the main satellite. In order to predict the time t required for terminal SU data transmission from the satellite req Spectrum holes within H i The idle probability, using Poisson distribution, has the following formula:

[0075]

[0076] In the formula, λ n Indicates the occupancy rate of the nth spectrum radio resource block RB by the terminal PU of the main satellite. i Indicates the spectrum hole H i Contains the number of spectrum radio resource blocks RB, and T represents the time unit.

[0077] S603. The terminal of the slave satellite determines the expected data transmission and switching time corresponding to the spectrum hole according to the probability that the spectrum hole is not occupied by the master satellite.

[0078] T E (H i ) represents the spectrum hole H i The expected data transmission and switching time of the spectrum hole is obtained from the amount of data transmitted by the satellite terminal, the probability that the spectrum hole is not occupied by the main satellite, the information transmission rate of the spectrum hole, the delay time of spectrum migration, and the delay time of spectrum switching. Then:

[0079]

[0080] Among them, T L2H Indicates the MAC switching delay time, T L3H Indicates the network layer switching delay.

[0081] For this step, in the process of determining the target spectrum loophole, the switching time between the second layer and the third layer of the satellite terminal is taken into account, and this technical solution supports cross-layer optimization management.

[0082] S604. The terminal from the satellite determines the target spectrum hole according to the expected data transmission and switching time of all spectrum holes.

[0083] Normally, after obtaining available spectrum holes from the satellite terminal, when selecting a spectrum from many spectrum holes, it is necessary to calculate the expected transmission time corresponding to each spectrum hole, select the target spectrum hole according to the expectation, and migrate the spectrum to the corresponding target spectrum hole through the switching program. In practical applications, when selecting a spectrum, the shortest expected transmission time is calculated, so that the cognitive satellite network system as a whole can reduce the probability of spectrum migration and achieve the purpose of improving system performance. For example: when selecting a spectrum hole for data transmission from the satellite terminal SU, select T E (H i )The smallest spectrum hole is:

[0084] H S =min(T E (H 1 ),T E (H 2 ),...T E (H i ), ...) (5)

[0085] As can be seen from formula (5), this technical solution is based on the prediction of the probability of the terminal of the main satellite to reclaim resources by observing the spectrum occupancy rate of the terminal of the slave satellite. After the terminal of the slave satellite obtains the available spectrum holes through spectrum sensing, the target spectrum hole is determined based on the shortest expected data transmission time when selecting a spectrum hole.

[0086] S605. The terminal from the satellite generates a corresponding spectrum request frame according to the spectrum leasing frame corresponding to the target spectrum hole.

[0087] In the spectrum sharing management mechanism of the cognitive satellite network system, the terminal of the slave satellite determines the spectrum occupancy rate and predicts the probability of the terminal of the main satellite to reclaim resources. After the terminal of the slave satellite obtains the available spectrum loopholes through spectrum sensing, when selecting a spectrum loophole from many spectrum loopholes, the expected transmission and switching time of each spectrum loophole is calculated, and the spectrum loophole with the expected transmission and switching time less than the threshold is selected as the target spectrum loophole, and the terminal of the slave satellite completes the spectrum migration and switching. When the expected data transmission time of the target spectrum loophole is the shortest, the defect of the current high-level spectrum management mechanism of the cognitive satellite network system that generally uses the maximum idle time scheme for spectrum loophole selection is overcome, and at the same time, the spectrum migration of the MAC layer and the switching of the network layer of the spectrum device of the terminal of the slave satellite in the cognitive satellite network system are supported, and the cross-layer protocol is realized, and the spectrum migration rate is reduced, thereby improving the overall performance of the cognitive satellite network system.

[0088] like Figure 8 FIG. 1 is a schematic diagram of a spectrum sharing system of a cognitive satellite network system. The system includes a terminal of a master satellite and a terminal of a slave satellite;

[0089] The terminal of the main satellite is used to send spectrum lease frames;

[0090] The terminal from the satellite is used to receive the spectrum lease frame, parse the spectrum lease frame, obtain the spectrum band that can be leased, and send the corresponding spectrum request frame according to the spectrum lease frame;

[0091] The terminal of the master satellite receives the spectrum request frame from the terminal of the slave satellite, parses the spectrum request frame, obtains the spectrum band requested for leasing and the corresponding leasing fee; matches the spectrum band available for leasing with the spectrum band requested for leasing, and if the match is successful, selects the highest leasing fee, allocates the spectrum band available for leasing to the corresponding terminal of the slave satellite, generates blocks at the same time, and sends the blocks to the blockchain network for verification.

[0092] In this embodiment, the leaseable spectrum band includes: a first frame preamble, a first frame type and a first information field; wherein the first information field includes: the leaseable spectrum band, lease time, usage area and minimum lease fee; the first frame type is the spectrum lease frame.

[0093] In this embodiment, the spectrum band requested for leasing includes: a second frame preamble, a second frame type and a second information field; the second information field includes: the spectrum band requested for leasing and spectrum electronic coins; the second frame type is the spectrum request frame.

[0094] In this embodiment, the block includes: blockchain header information, leased spectrum band, lease time, usage area, slave user node information and lease transaction information.

[0095] In this embodiment, the block includes blockchain header information, leased spectrum band, lease time, usage area, slave user node information, and lease transaction information.

[0096] like Figure 3 As shown, the terminal from the satellite includes:

[0097] The spectrum sensing module is used to sense all spectrum wireless resource blocks of the main satellite from the satellite terminal, obtain the spectrum bands that can be leased, and the spectrum bands that can be leased constitute spectrum loopholes; and obtain the occupancy rate of the spectrum wireless resource blocks occupied by the main satellite;

[0098] The spectrum analysis module is used to determine the probability that the spectrum hole is not occupied by the main satellite according to the occupancy rate of the terminal of the slave satellite;

[0099] The first spectrum decision module is used to determine the expected data transmission and switching time of the corresponding spectrum hole according to the probability that the spectrum hole is not occupied by the main satellite from the terminal of the satellite;

[0100] A second spectrum decision module is used to determine a target spectrum hole from a terminal of the satellite according to expected data transmission and switching time of all spectrum holes;

[0101] The spectrum request frame generation module is used to generate a corresponding spectrum request frame from the satellite terminal according to the spectrum leasing frame corresponding to the target spectrum hole.

[0102] In this embodiment, the spectrum analysis module includes:

[0103] an information transmission rate determination unit, configured to determine an information transmission rate of the spectrum hole according to a signal-to-noise ratio of a terminal from the satellite, the number of spectrum wireless resource blocks in the spectrum hole, and the spectrum of the spectrum wireless resource block;

[0104] A transmission time determination unit, configured to determine a corresponding transmission time according to an amount of data to be transmitted from a terminal requesting the satellite and an information transmission rate of a spectrum hole;

[0105] The probability determination unit is used to determine the probability that the spectrum hole is not occupied by the main satellite according to the occupancy rate of the spectrum wireless resource block occupied by the main satellite, the transmission time, and the number of spectrum wireless resource blocks in the spectrum hole.

[0106] In this embodiment, the first spectrum decision module is further used for:

[0107] The expected data transmission and switching time of the spectrum hole are obtained from the amount of data transmission requested by the satellite terminal, the probability that the spectrum hole is not occupied by the main satellite, the information transmission rate of the spectrum hole, the delay time of spectrum migration, and the delay time of spectrum switching.

[0108] In this embodiment, the target spectrum hole determined by the second spectrum decision module is the spectrum hole corresponding to the smallest expected data transmission and switching time among all spectrum holes.

[0109] Those skilled in the art also know that, in addition to implementing the client and server in a purely computer-readable program code, the client and server can be made to implement the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, such a client and server can be considered as a hardware component, and the means for implementing various functions included therein can also be considered as a structure within the hardware component. Or even, the means for implementing various functions can be considered as both a software module for implementing the method and a structure within the hardware component.

[0110] It can be known from the description of the above implementation modes that those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of various implementation modes of the present application or certain parts of the implementation modes.

[0111] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the implementation of the client and the server, the introduction of the implementation of the aforementioned method can be referred to for comparative explanation.

[0112] The present application may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0113] The embodiments described above are only descriptions of the preferred methods of the present application, and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements made to the technical solutions of the present application by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present application.

Claims

1. A cognitive satellite network spectrum sharing method based on blockchain smart contract verification, which is applied to a cognitive dual-satellite network system and is characterized in that: The cognitive dual-satellite network system includes: a master satellite and a slave satellite; wherein the master satellite and the slave satellite cover the same area, the terminal of the master satellite is called a master user node, and the terminal of the slave satellite is called a slave user node; the master user node and the slave user node form a blockchain network through a known public control channel; the method steps include: Sending a spectrum lease frame through a terminal of the primary satellite; The terminal from the satellite receives and parses the spectrum lease frame to obtain a spectrum band that can be leased; and sends a corresponding spectrum request frame according to the spectrum lease frame; The terminal of the main satellite receives and parses the spectrum request frame to obtain the spectrum band requested for leasing and the corresponding leasing fee; Matching the leaseable spectrum band with the spectrum band requested for lease to obtain a matching result; According to the matching result, the highest lease fee is selected, the leaseable spectrum band is allocated to the corresponding terminal of the slave satellite and a block is generated; The block is sent to the blockchain network for verification to complete the cognitive satellite network spectrum sharing.

2. According to claim 1, the cognitive satellite network spectrum sharing method based on blockchain smart contract verification is characterized in that: The spectrum leasing frame includes: a first frame preamble, a first frame type and a first information field; wherein the first information field includes: the leaseable spectrum band, lease time, usage area and minimum lease fee; the first frame type is the spectrum leasing frame.

3. According to claim 1, the cognitive satellite network spectrum sharing method based on blockchain smart contract verification is characterized in that: The spectrum band requested for leasing includes: a second frame preamble, a second frame type and a second information field; the second information field includes: the spectrum band requested for leasing and spectrum electronic coins; the second frame type is the spectrum request frame.

4. The cognitive satellite network spectrum sharing method based on blockchain smart contract verification according to claim 1 is characterized in that: The block includes: blockchain header information, leased spectrum band, lease time, usage area, slave user node information and lease transaction information.

5. The cognitive satellite network spectrum sharing method based on blockchain smart contract verification according to claim 1 is characterized in that: The method for obtaining the leaseable spectrum band includes: obtaining the leaseable spectrum band by sensing all spectrum wireless resource blocks of the master satellite through the terminal of the slave satellite; wherein the leaseable spectrum band constitutes a target spectrum loophole.

6. According to claim 5, the cognitive satellite network spectrum sharing method based on blockchain smart contract verification is characterized in that: The method for sending the corresponding spectrum request frame includes: Calculating the occupancy rate of all spectrum wireless resource blocks occupied by the main satellite; Obtaining a probability that the target spectrum hole is not occupied by the primary satellite based on the target spectrum hole and the occupancy rate; Determining expected data transmission and switching time corresponding to the target spectrum hole according to the probability; Determine the target spectrum hole according to the expected data transmission and switching time of all spectrum holes; The corresponding spectrum request frame is generated according to the spectrum leasing frame corresponding to the target spectrum hole.

7. The cognitive satellite network spectrum sharing method based on blockchain smart contract verification according to claim 6 is characterized in that: Methods for determining the probability include: Determine the information transmission rate of the spectrum hole according to the signal-to-noise ratio of the terminal of the slave satellite, the number of spectrum wireless resource blocks in the target spectrum hole, and the spectrum of the spectrum wireless resource blocks; Determine a corresponding transmission time according to the amount of data requested to be transmitted by the terminal of the slave satellite and the information transmission rate; The probability is determined according to the occupancy rate, the transmission time and the number of spectrum radio resource blocks.

8. The cognitive satellite network spectrum sharing method based on blockchain smart contract verification according to claim 7 is characterized in that: The method for determining the expected data transmission and switching time includes: obtaining the expected data transmission and switching time according to the probability, the information transmission rate, the delay time of spectrum migration and the delay time of spectrum switching.

9. The cognitive satellite network spectrum sharing method based on blockchain smart contract verification according to claim 8 is characterized in that: The target spectrum hole is a spectrum hole corresponding to the expected data transmission and switching time that is the smallest among all the spectrum holes.

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