A method for long-distance communication in sea areas under unknown communication channel conditions

Abstract

The present invention provides a method for long-distance communication in the sea area under the condition of unknown communication channel, which belongs to the field of sea area communication technology. It solves the problem that traditional sea area communication is limited by the difficulty of accurate acquisition of channels. Its technical scheme is: including the following steps: S1, dividing the communication grid area; S2, determining the communication demand grid set; S3, constructing the communication demand grid virtual queue and calculating the average benefit of the beam grid combination; S4, calculating the beam corresponding grid evaluation function and selecting the maximum value combination; S5, after receiving the data, the ship feeds back confirmation information to the base station and broadcasts the data in the grid; S6, the base station updates the waiting virtual queue and average benefit according to the feedback information; S7, repeating steps S3 to S7 when the communication grid set does not change, otherwise repeating steps S2 to S7. The beneficial effects of the present invention are: the present invention does not rely on the sea area channel state information, and adaptively adjusts the selection of beams and service ships.

Description

Technical Field

[0001] The present invention relates to the field of sea area communication technology, and in particular to a sea area long-distance communication method under the condition of unknown communication channel. Background Art

[0002] In recent years, the marine economy has become an important way for coastal countries around the world to expand their economic and social development space. The rapid development of the marine economy has created a great demand for technologies such as monitoring data transmission, real-time video interaction, and multimedia content acquisition. At present, marine broadband communications, which are mainly based on satellite communications, have problems such as high technical barriers and expensive bandwidth resources, and it is difficult to meet the growing demand for communication services. Therefore, it is urgent to develop a marine broadband wireless communication network and conduct in-depth exploration of key technologies and implementation of marine broadband wireless communications to adapt to the continuous development of the marine economy.

[0003] Due to the influence of factors such as propagation distance, scattering, sea surface wave motion, and evaporation duct layer, the propagation environment in the near sea presents uncertain characteristics. The long transmission distance and large delay of offshore communications will increase the difficulty of obtaining instantaneous channel state information in large-scale antenna communications. The instantaneous channel state information obtained through pilot signal measurement is more inaccurate or outdated. In addition, in the actual communication process, prior information such as scattering, sea surface wave motion, and evaporation duct layer is difficult to obtain in real time and will change over time. The statistical channel state information between ships and shore-based base stations changes significantly. Traditional wireless communication technology based on obtaining channel state information is difficult to apply to marine scenarios, and it is necessary to design a marine wireless communication method that does not rely on channel state information. Summary of the invention

[0004] The purpose of the present invention is to provide a method for long-distance communication in sea areas under the condition of unknown communication channels, which is independent of sea area channel status information and adaptively adjusts the selection of beams and service ships.

[0005] The inventive concept of the present invention is as follows: the communication system in the present invention is composed of a base station on the coast and a communication ship in the sea area. The base station divides the communication grid area according to the coverage range, obtains the geographical location information of the ship through the AIS information sent by the ship, and determines the number of ships in each communication area grid; according to the grid with communication demand and the beam possessed by the base station antenna, a combination set of beams and communication demand grids is established; according to the communication situation between the beam and the communication demand grid, an evaluation function between the beam and the grid, and a virtual queue of the grid waiting for communication service are established; further comprehensively considering the evaluation function and the length of the virtual queue, the base station decides the beam to be used in the next time slot and the grid to be served; when a ship in the grid receives a message from the base station, it is transmitted to other ships in the form of broadcasting. The present invention can realize sea area ship communication services under the condition that the communication channel is completely unknown through the communication interaction between the base station beam and the sea area ships in grid units, and can take into account the fairness of communication between ships, thereby improving the quality of sea area communication services.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is specifically: a method for long-distance communication in sea area under the condition of unknown communication channel, comprising the following steps:

[0007] Step S1, the base station divides the communication grid area according to the coverage area;

[0008] Step S2: Obtain the geographical location information of the ship through the AIS information sent by the ship, determine the grid set with communication needs, the number of ships in each communication area grid, and calculate the communication demand ratio of each grid;

[0009] Step S3: According to the grids with communication requirements and the beams possessed by the base station antennas, a combination set of beams and grids with communication requirements is established, a waiting virtual queue of the grids with communication requirements is constructed, and the average benefits of the beams and the corresponding grids are calculated;

[0010] Step S4: At the beginning of each communication time slot, the base station calculates the beam and the corresponding grid evaluation function, and selects the beam and grid combination that maximizes the evaluation function for communication;

[0011] Step S5: After a ship in the served grid successfully receives the message sent by the base station, it feeds back 1 bit of information to the base station to indicate successful reception, and sends the received information to other ships by broadcasting within the grid;

[0012] Step S6: After the communication time slot ends, the base station updates the waiting virtual queue, beam and average revenue of the corresponding grid of the communication demand grid according to the received ship feedback information;

[0013] Step S7, determine whether the grid set with communication needs has changed. If not, provide communication services to ships in the sea area according to steps S3 to S7 in each communication time slot. If changed, provide communication services to ships in the sea area according to steps S2 to S7.

[0014] As a further optimization scheme of a method for long-distance communication in sea areas under unknown communication channel conditions provided by the present invention, in step S1, the steps of dividing the communication grid area according to the coverage range are as follows:

[0015] Step R1, the shore base station divides the communication service grid according to the distance d and the angle θ between the coverage area and the base station;

[0016] Step R2: Divide the area into N areas {0~d1, d1~d2, ..., d N-1 ~d N}, where d1<d2<…<d N ;

[0017] Step R3: Divide the angle into M parts {θ max ~θ1,θ1~θ2,…,θ M-1 ~θ min}, where, θ1>θ2>…>θ M-1 ,θ max and θ min is the maximum and minimum angles that the antenna can cover;

[0018] Step R4: divide a total of M×N areas according to the divided distances and angles.

[0019] As a further optimization scheme of the method for long-distance communication in sea areas under unknown communication channel conditions provided by the present invention, the specific content of the communication demand ratio of step S2 is:

[0020]

[0021] in Representation Grid The number of ships in is the set of grids with communication requirements, and K represents the number of grids with communication requirements.

[0022] As a further optimization scheme of the method for long-distance communication in sea areas under unknown communication channel conditions provided by the present invention, the average gain of the beam and the corresponding grid in step S3 is:

[0023]

[0024] where g kl(t) = 1 means that beam b is selected in time slot t l Service Mesh Otherwise, it is 0. kl (t) = 1 means that beam b in time slot t l Success Service Grid And the base station receives the grid Feedback if the ship successfully receives the message, otherwise it is 0.

[0025] As a further optimization scheme of a method for long-distance communication in sea areas under unknown communication channel conditions provided by the present invention, the method for constructing a waiting virtual queue of the communication demand grid in step S6 is:

[0026]

[0027] where q k (t) represents the grid The length of the waiting virtual queue at time slot t.

[0028] As a further optimization scheme of a method for long-distance communication in sea areas under unknown communication channel conditions provided by the present invention, the selection process of the base station beam and the service grid in step S5 is as follows:

[0029] Step T1: The base station is equipped with an array antenna, the number of antennas is G, and a beam set can be generated according to the characteristics of the antenna itself. {b1,…,b l , …, b L};

[0030] Step T2: Construct the corresponding space between beam and grid service {a 11 , …, a kl , …, a KL}, where a kl Indicates the use of beam b l Service Mesh

[0031] Step T3, in time slot t, calculating the beam and the corresponding grid evaluation function;

[0032] Step T4: If multiple beam and grid combinations are calculated in step T3, one is randomly selected for communication; otherwise, the beam and grid combination that maximizes the evaluation function is selected for communication.

[0033] As a further optimization scheme of the method for long-distance communication in sea areas under unknown communication channel conditions provided by the present invention, the beam and corresponding grid evaluation function in step S4 is:

[0034]

[0035] Where v is the trade-off coefficient between the overall system performance and the fairness of the communication services for each grid. The larger the ξ, the more attention is paid to the fairness of the communication services for each grid.

[0036] As a further optimization scheme for a method for long-distance communication in sea areas under unknown communication channel conditions provided by the present invention, the communication process between the base station and the ship does not obtain the channel state information of each user and the base station in advance, and only feeds back 1 bit of information after the ship receives the information sent by the base station.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The present invention proposes a sea area communication method under a blind channel, which adapts to the uncertainty characteristics of the sea area propagation environment and adaptively selects base station beams to serve sea area users without relying on sea area channel state information.

[0039] 2. The present invention constructs a waiting virtual queue of the communication demand grid and a beam corresponding grid evaluation function, which can take into account the overall performance of the system and the fairness of communication between grids, and can accurately manage different communication users through weighing coefficients.

[0040] 3. In the present invention, there is no need to perform channel estimation between the base station and the ship. The ship only needs to feedback 1 bit of confirmation information after successfully receiving the data, which can greatly reduce the high communication overhead caused by the handshake interaction between the two parties in long-distance communication and improve communication efficiency and service quality.

[0041] 4. The communication base station in the present invention is compatible with the ground mobile communication network. Compared with the traditional sea area broadband communication based on satellite communication, it has the characteristics of low price, low latency, high bandwidth, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0043] Figure 1 The figure is a schematic diagram of a long-distance communication scenario in sea areas under the condition of unknown communication channels according to the present invention.

[0044] Figure 2 The present invention is a flow chart of a method for long-distance communication in sea areas under conditions where the communication channel is unknown.

[0045] Figure 3 This is a flow chart for selecting the base station beam and service grid of the present invention.

[0046] Wherein, the accompanying drawings are marked as follows:

[0047] 101. Shore-based base station; 102. Ships distributed within the coverage area of ​​the base station; 103. Beam used by the base station when serving a grid; 104. Broadcasting and sharing of received information between ships within the grid; 105. Service grid area divided according to the method of this embodiment. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Of course, the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0049] Example 1

[0050] See also Figures 1 to 3 The technical solution provided in this embodiment is as follows: Figure 1 The system consists of a shore-based base station 101 equipped with an array antenna; ships 102 distributed within the coverage of the base station, beams 103 used by the base station when serving a grid, broadcasting and sharing of received information 104 between ships in the grid, and service grid areas 105 divided according to the method of this embodiment.

[0051] This example is based on the interaction between the base station and the service grid to implement a communication method under the condition of unknown channel state information. The communication flow chart is as follows: Figure 2 shown.

[0052] Step S1: The shore base station divides the communication service grid according to the distance d and angle θ between the coverage area and the base station. According to the distance from the base station, N areas {0~d1, d1~d2, ..., d N-1 ~d N}, where d1<d2<…<d N According to the angle between the east-west direction and the base station, the angle is divided into M parts {θ max ~θ1,θ1~θ2,…,θ M-1 ~θ min}, where θ1>θ2>…>θ M-1 ,θ max and θ min is the maximum angle and minimum angle that the antenna can cover. So far, a total of M×N areas are divided.

[0053] Step S2: Obtain the geographical location information of the ship through the AIS information sent by the ship, and determine the grid set with communication needs K represents the total number of grids with communication needs and the number of ships in each communication area grid. And calculate the proportion of communication demand of each grid

[0054] Step S3: According to the grids with communication requirements and the beams possessed by the base station antennas, a combination set of beams and grids with communication requirements is established, a waiting virtual queue of grids with communication requirements is constructed, and an average benefit of the beams and corresponding grids is calculated.

[0055] Specifically, Figure 3 As shown, according to step T1, the base station is equipped with an array antenna, the number of antennas is G, and a beam set can be generated according to the characteristics of the antenna itself. {b1,…,b l , …, b L}, L is the total number of beams.

[0056] According to step T2, a combination set of beams and communication demand grids is constructed. {a 11 , …, a kl , …, a KL}, where a kl Indicates the use of beam b l Service Mesh

[0057] Further, construct a waiting virtual queue for the communication demand grid where q k (t) represents the grid The length of the waiting virtual queue at time slot t, f kl (t) = 1 means that beam b in time slot t l Success Service Grid And the base station receives the grid The feedback that the ship successfully receives the information is 0 otherwise. Calculate the average gain of the beam and the corresponding grid where g kl (t) = 1 means that beam b is selected in time slot t l Service Mesh

[0058] Step S4: At the beginning of each communication time slot, the base station calculates the evaluation function of the beam and the corresponding grid, and selects the beam and grid combination that maximizes the evaluation function for communication.

[0059] Specifically, according to step T3, in time slot t, the beam and the corresponding grid evaluation function are calculated Where ξ is the trade-off coefficient between the overall system performance and the fairness performance of serving each grid communication. The larger the ξ is, the more attention is paid to the fairness of each grid communication service. The typical value can be set to ξ=1.

[0060] According to step T4, calculate If there is more than one solution, let the set of solutions be From the collection One is randomly selected with medium probability otherwise, select to communicate.

[0061] Step S5: When a ship in the served grid successfully receives the message sent by the base station, it feeds back 1 bit of information to the base station to indicate successful reception, and sends the received information to other ships by broadcasting within the grid;

[0062] Step S6: After the communication time slot ends, the base station updates the waiting virtual queue, beam and average revenue of the corresponding grid of the communication demand grid according to the received ship feedback information. Specifically, when the grid where the ship receiving the feedback information is located is located, its virtual queue is updated to The virtual queues for other grids are updated as The average gain of the beam and the corresponding grid is updated as

[0063] Step S7: Determine the grid set with communication requirements Check whether there is any change. If not, provide communication services to ships in the sea area according to steps S3 to S7 in each communication time slot; if there is any change, provide communication services to ships in the sea area according to steps S2 to S7.

[0064] The sea area communication method under the blind channel proposed in this embodiment does not rely on the sea area channel state information, can take into account the overall performance of the system and the fairness of communication between grids, adaptively adjust the selection of beams and communication service grids, and improve the communication service quality for ships in the sea area.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for long-distance communication in sea areas under the condition of unknown communication channel, characterized in that: The following steps are involved: Step S1, the base station divides the communication grid area according to the coverage area; In step S1, the steps of dividing the communication grid area according to the coverage range are as follows: Step R1, the shore base station divides the communication service grid according to the distance d and the angle θ between the coverage area and the base station; Step R2: Divide N regions {0~d1, d1~d2, ..., d N-1 ~d N }, where d1<d2<…<d N ; Step R3: Divide the angle into M parts {θ max ~θ1,θ1~θ2,…,θ M-1 ~θ min }, where, θ1>θ2>…>θ M-1 ,θ max and θ min is the maximum and minimum angles that the antenna can cover; Step R4, dividing a total of M×N areas according to the divided distances and angles; Step S2: Obtain the geographical location information of the ship through the AIS information sent by the ship, determine the grid set with communication needs, the number of ships in each communication area grid, and calculate the communication demand ratio of each grid; The specific content of the communication demand ratio in step S2 is: in Representation Grid The number of ships in is the set of grids with communication requirements, K represents the number of grids with communication requirements; Step S3: According to the grids with communication requirements and the beams possessed by the base station antennas, a combination set of beams and grids with communication requirements is established, a waiting virtual queue of the grids with communication requirements is constructed, and the average benefits of the beams and the corresponding grids are calculated; The average gain of the beam and the corresponding grid in step S3 is: where g kl (t) = 1 means that beam b is selected in time slot t l Service Mesh Otherwise, it is 0. kl (t) = 1 means that beam b in time slot t l Success Service Grid And the base station receives the grid Feedback that the internal ship successfully received the information, otherwise it is 0; Step S4: At the beginning of each communication time slot, the base station calculates the beam and the corresponding grid evaluation function, and selects the beam and grid combination that maximizes the evaluation function for communication; The beam and corresponding grid evaluation function in step S4 is: Where ξ is the trade-off coefficient between the overall system performance and the fairness performance of serving each grid communication. The larger the ξ, the more attention is paid to the fairness of each grid communication service. Step S5: After a ship in the served grid successfully receives the message sent by the base station, it feeds back 1 bit of information to the base station to indicate successful reception, and sends the received information to other ships by broadcasting within the grid; The selection process of the base station beam and the service grid in step S5 is as follows: Step T1: The base station is equipped with an array antenna, the number of antennas is G, and a beam set can be generated according to the characteristics of the antenna itself. Step T2: Construct the corresponding space between beam and grid service where a kl Indicates the use of beam b l Service Mesh Step T3, in time slot t, calculating the beam and the corresponding grid evaluation function; Step T4: If multiple beam and grid combinations are calculated in step T3, one is randomly selected for communication; otherwise, the beam and grid combination that maximizes the evaluation function is selected for communication; Step S6: After the communication time slot ends, the base station updates the waiting virtual queue, beam and average revenue of the corresponding grid of the communication demand grid according to the received ship feedback information; The method for constructing the waiting virtual queue of the communication demand grid in step S6 is: where q k (t) represents the grid The length of the waiting virtual queue at time slot t; Step S7, determine whether the grid set with communication needs has changed. If not, provide communication services to ships in the sea area according to steps S3 to S7 in each communication time slot. If changed, provide communication services to ships in the sea area according to steps S2 to S7.

2. The method for long-distance communication in sea area under unknown communication channel condition according to claim 1, characterized in that: The communication process between the base station and the ship does not obtain the channel state information between each user and the base station in advance, and the ship only feeds back 1 bit of information after receiving the information sent by the base station.

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