A simulation method for frequency-hopping time-division multiple access synchronous orthogonal network

Abstract

The present invention belongs to the field of frequency hopping communication transmission, and provides a method for simulating a frequency hopping time division multiple access synchronous orthogonal network, including: basic information acquisition, frequency hopping pattern calculation, time header and channel header addition, message broadcasting, extended header comparison and message reception. The present invention realizes virtual physical isolation by adding time header and channel header to air interface messages, avoids the influence of frequency hopping library number, network time, network number and encryption sequence, reduces interference between network members, and solves the problems of difficulty in realizing transmission waveform and difficulty in ensuring synchronous orthogonality.

Description

Technical Field

[0001] The invention relates to the field of frequency hopping communication transmission, in particular to a frequency hopping time division multiple access synchronous orthogonal network simulation method. Background Art

[0002] Frequency-hopping time-division multiple access synchronous orthogonal network is a typical network architecture in tactical communication networks. This network architecture adopts the physical layer transmission technology of frequency-hopping communication and the data link layer media access control technology of time-division multiple access, and uses unified network time and multiple channels to realize synchronous orthogonal network, which can significantly improve network user capacity and throughput.

[0003] At present, the simulation of frequency hopping time division multiple access synchronous orthogonal network is mainly based on the simulation method of the real air interface. However, there are two difficulties in this type of simulation. On the one hand, the simulation method needs to realize the physical layer transmission waveform, including baseband processing such as channel coding, modulation and demodulation, channel interleaving / deinterleaving, and RF processing such as frequency hopping pattern generation and pulse shaping, which has high implementation complexity. On the other hand, the method relies on the high-precision local clock of the network members to maintain the time synchronization of the whole network. It is difficult to ensure synchronous orthogonal network without high-precision clocks. Therefore, the existing frequency hopping time division multiple access synchronous orthogonal network simulation method needs to realize the physical layer transmission waveform, but the transmission waveform is affected by parameters such as frequency hopping library number, network time, network number, encryption sequence, etc., which is difficult to implement; in the simulation, the network members rely on high-precision local clocks to keep synchronization with the network time. Network members without high-precision local clocks may cause time slot interference to the transmission of other network members, making it difficult to ensure synchronous orthogonal networking. The above problems will reduce the accuracy of network simulation and even make the network simulation invalid. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a frequency hopping time division multiple access synchronous orthogonal network simulation method, which achieves virtual physical isolation by adding a time header and a channel header to the air interface message, avoids the influence of the frequency hopping library number, network time, network number, and encryption sequence, reduces interference between network members, and solves the problems of difficulty in realizing the transmission waveform and difficulty in ensuring synchronous orthogonality.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A frequency hopping time division multiple access synchronous orthogonal network simulation method, comprising:

[0007] When the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, the frequency hopping library number, the network number and the encryption sequence are obtained;

[0008] Calculate a frequency hopping pattern according to the network time, the frequency hopping library number, the network number and the encryption sequence to obtain an original air interface message;

[0009] Adding a time header and a channel header to the original air interface message to obtain a simulated air interface message; the time header includes: an hour number, a time frame number and a time slot number; the channel header includes: a frequency hopping library number, a network number and an encryption sequence;

[0010] Sending the simulated air interface message to a switching device through an Ethernet port, and broadcasting the simulated air interface message to a synchronous orthogonal network using the switching device;

[0011] After receiving the simulated air interface message, the networking protocol module of the receiver parses the extended header of the simulated air interface message to obtain the time header and the channel header;

[0012] When the time slot numbers in the time header and the preset extension header are inconsistent and the channel parameters in the channel header and the preset extension header are consistent, the simulated air interface message is received.

[0013] Preferably, the calculation formula of the frequency hopping pattern is: m,n =F(t TON ,I lib ,I net ,S enc );f m,n is the frequency point at which the network member sends the RF signal on the nth channel in the mth time slot; F(·) is the nonlinear transformation function; t TON is the network time; lib is the frequency hopping library number; net is the network number; S enc is the encryption sequence.

[0014] Preferably, when the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, the frequency hopping library number, the network number and the encryption sequence are obtained, including:

[0015] Setting a network member as a time master, and setting network members other than the time master as time slaves;

[0016] Using the time master to periodically send service messages;

[0017] receiving the service message from the station using the time;

[0018] The local time of the time slave station is adjusted according to the service message, and the local time is determined as the network time.

[0019] Preferably, when the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, the frequency hopping library number, the network number and the encryption sequence are obtained, including:

[0020] Preset a network planning file and send the network planning file to all network members;

[0021] The network planning file is parsed to obtain the frequency hopping library number and the network number.

[0022] Preferably, when the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, the frequency hopping library number, the network number and the encryption sequence are obtained, and the following steps are further included:

[0023] When the network time is determined, the network time is sent to a preset security machine;

[0024] The encryption sequence is generated using the encryption engine according to the network time.

[0025] Preferably, the service message is transmitted using a preset frequency hopping pattern.

[0026] The present invention discloses the following technical effects:

[0027] The present invention provides a frequency hopping time division multiple access synchronous orthogonal network simulation method, which solves the problems of difficulty in realizing transmission waveform and difficulty in ensuring synchronous orthogonality by adding time header and channel header to air interface message, and realizes virtual physical isolation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 A schematic diagram of a frequency hopping time division multiple access synchronous orthogonal network simulation process provided by an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of the transmission principle provided by an embodiment of the present invention;

[0031] Figure 3 A schematic diagram of time slot usage provided by an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of a node model provided by an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of the connection relationship provided by an embodiment of the present invention;

[0034] Figure 6 A schematic diagram of an Ethernet port receiving a service message according to an embodiment of the present invention;

[0035] Figure 7 A schematic diagram of the structure of a simulated air interface message frame provided by an embodiment of the present invention;

[0036] Figure 8 A schematic diagram of a processing flow of a sender provided in an embodiment of the present invention;

[0037] Fig. 9 A schematic diagram of a receiving side processing flow provided by an embodiment of the present invention;

[0038] Fig.10 A schematic diagram of a simulation process provided by an embodiment of the present invention. DETAILED DESCRIPTION

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

[0040] The purpose of the present invention is to provide a frequency hopping time division multiple access synchronous orthogonal network simulation method, which realizes virtual physical isolation by adding a time header and a channel header to the air interface message, avoids the influence of the frequency hopping library number, network time, network number, and encryption sequence, reduces interference between network members, and solves the problems of difficulty in realizing the transmission waveform and difficulty in ensuring synchronous orthogonality.

[0041] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Figure 1 The schematic diagram of the simulation flow of the frequency hopping time division multiple access synchronous orthogonal network provided in this embodiment is as follows: Figure 1 As shown, this embodiment provides a frequency hopping time division multiple access synchronous orthogonal network simulation method, including:

[0043] When the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, the frequency hopping library number, the network number and the encryption sequence are obtained;

[0044] The frequency hopping pattern is calculated according to the network time, the frequency hopping library number, the network number and the encryption sequence to obtain the original air interface message;

[0045] Adding a time header and a channel header to the original air interface message to obtain a simulated air interface message; the time header includes: time unit number, time frame number and time slot number; the channel header includes: frequency hopping library number, network number and encryption sequence;

[0046] Send the simulated air interface message to the switching device through the Ethernet port, and use the switching device to broadcast the simulated air interface message to the synchronous orthogonal network;

[0047] After receiving the simulated air interface message, the networking protocol module of the receiver parses the extended header of the simulated air interface message to obtain the time header and the channel header;

[0048] When the time slot numbers in the time header and the preset extension header are inconsistent and the channel parameters in the channel header and the preset extension header are consistent, the simulated air interface message is received.

[0049] Specifically, the calculation formula of the frequency hopping pattern is: m,n =F(t TON ,I lib ,I net ,S enc );f m,n is the frequency point at which the network member sends the RF signal on the nth channel in the mth time slot; F(·) is the nonlinear transformation function; t TON is the network time; lib is the frequency hopping library number; net S is the network number; enc The encryption sequence.

[0050] Further, when the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, the frequency hopping library number, the network number and the encryption sequence are obtained, including:

[0051] Set one network member as the time master, and set all network members except the time master as time slaves;

[0052] Use the time master to periodically send service messages;

[0053] Use time to receive service messages from the station;

[0054] Adjust the local time of the time slave station according to the service message and determine the local time as the network time.

[0055] Furthermore, when the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, the frequency hopping library number, the network number and the encryption sequence are obtained, including:

[0056] Preset network planning files and send them to all network members;

[0057] Parse the network planning file to obtain the frequency hopping library number and network number.

[0058] Specifically, when the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, the frequency hopping library number, the network number and the encryption sequence are obtained, and the following steps are also included:

[0059] When the network time is determined, the network time is sent to the preset security machine;

[0060] Generate an encryption sequence using a cryptographic machine based on network time.

[0061] Optionally, the service message is transmitted using a preset frequency hopping pattern.

[0062] refer to Figure 2 , Figure 2 It is the frequency hopping pattern of the signal transmitted by all network members in a certain time slot, in which a total of 16 working frequencies are used, namely frequencies 1 to 16, and each time slot contains 8 hops; the baseband signal generated by each network member needs to be processed by channel coding, interleaving, scrambling, etc., and the frequency hopping pattern of the radio frequency signal is controlled by parameters such as network time, frequency hopping library number, network number, encryption sequence, etc. In this embodiment, the multi-channel signal transmission that does not interfere with each other in a certain time slot is called a "channel", and each channel carries the service transmission of a subnet. Figure 2 The frequency-hopping TDMA synchronous orthogonal network shown in FIG. 4 includes 4 channels, corresponding to 4 subnets in total.

[0063] refer to Figure 3 In a frequency hopping TDMA synchronous orthogonal network, the transmission mode of network members is half-duplex, that is, they are in the sending or receiving state within a time slot, and cannot send and receive at the same time. Each time slot on different channels can be allocated to different network members to send service messages. The time slots are used as follows: Figure 3 As shown. The network contains 4 channels, namely channels 1 to 4. The figure shows the channel allocation of 3 time slots. Taking channel 1 as an example, the first time slot is allocated to node 24 for sending broadcast services; the second time slot is allocated to node 54 for sending unicast services, with the destination node being 78; the third time slot is allocated to node 46 for sending unicast services, with the destination node being 24. Because all network members are synchronized with the network time, there is no mutual interference between time slots.

[0064] Optionally, in a real frequency-hopping TDMA synchronous orthogonal network, the transmission and reception between network members can be time-isolated through MAC layer TDMA scheduling, and channel isolation can be achieved through physical layer transmission waveform (both time isolation and channel isolation isolate the real signals between network members, so they are collectively referred to as physical isolation), and logical isolation can be achieved through the destination node address in the service message header.

[0065] refer to Figure 4The node model of the network member designed in this embodiment is composed of a networking protocol module and an interface processing module, and uses an Ethernet port to exchange information externally. The networking protocol module implements TDMA protocol processing, including the maintenance of the time slot table, network time update, etc. The interface processing module implements external information transmission, including the sending and receiving processing of application layer service messages and the sending and receiving processing of simulated air interface messages.

[0066] refer to Figure 5 , each network member is connected to the switching device through the Ethernet port; the interface processing module of the network member packages the service message and sends it to the switching device or receives the service message sent by other network members from the switching device, thereby simulating the sending and receiving of air interface messages. The physical layer electrical characteristics and link layer of the Ethernet port comply with the provisions of GB / T 15629.3-2014, the network layer adopts the Internet Protocol IP provisions, and the transport layer uses the UDP protocol in the TCP / IP protocol family.

[0067] refer to Figure 6 Considering that the simulated air interface message transmission based on the Ethernet port is broadcast, and the simulated air interface message transmission and reception cannot guarantee synchronous orthogonality, each network member will receive the simulated air interface messages sent by all other network members. Figure 3 The described time slot usage mode, the simulated air interface message received by the network member from the switching device through the Ethernet port is the simulated air interface message sent by all network members. After receiving, the network member can parse the destination address in the simulated air interface message header to determine whether the local needs to receive and process it.

[0068] Furthermore, this embodiment realizes virtual physical isolation by simulating the extended header of the air interface message, including virtual physical isolation at two levels: time and channel. The process is as follows:

[0069] 1) Frequency hopping pattern calculation:

[0070] Considering a real frequency hopping TDMA synchronous orthogonal network, the frequency hopping pattern of the RF signal is controlled by parameters such as network time, frequency hopping library number, network number, encryption sequence, etc. m,n represents the frequency of a network member sending a radio frequency signal on the nth channel in the mth time slot, then f m,n It can be expressed as:

[0071] f m,n =F(t TON ,I lib ,I net ,S enc )

[0072] Where F(·) represents the nonlinear transformation of the independent variable in the brackets, which varies in different transmission waveforms; t TONIndicates network time, which can be expressed in various forms such as "epoch number-time frame number-time slot number" or "year-month-day-millisecond"; I lib Indicates the frequency hopping library number, which is the index number corresponding to the frequency point set composed of multiple frequency hopping points; I net Indicates the network number; S enc Represents an encrypted sequence.

[0073] 2) Parameter acquisition:

[0074] Network time acquisition:

[0075] The frequency-hopping TDMA synchronous orthogonal network adopts a master-slave synchronization method. In this method, one network member is set as the time master and the other members are set as time slaves. The time master periodically sends service messages; the service messages use a fixed frequency-hopping pattern to facilitate reception by other network members, and the service messages contain the local time of the time master. The time slaves use a fixed frequency-hopping pattern to search for and receive service messages. After reception, they adjust their own time according to the local time of the time master in the service message, thereby achieving time synchronization with the time master. When all time slaves achieve time synchronization, all network members will use the local time of the time master as the network time, i.e., t TON .

[0076] Obtain the frequency hopping library number and network number:

[0077] Before the frequency hopping TDMA synchronous orthogonal network is opened, the frequency hopping library number and network number used by each subnet will be planned and a network planning file will be generated. In the network planning file, network members that need to interact with each other will be assigned the same frequency hopping library number and network number. After the planning is completed, the network planning file will be loaded to each network member. Each network member obtains the frequency hopping library number used locally by parsing the network planning file. lib and network number I net .

[0078] Encrypted sequence acquisition:

[0079] The frequency-hopping TDMA synchronous orthogonal network uses the encryption sequence output by the security machine to control the frequency hopping pattern and realize channel encryption. The encryption sequence output by the security machine changes dynamically with the network time to further enhance security. After obtaining the network time, the network member sends the network time to the security machine; the security machine outputs the encryption sequence according to the network time. The network member reads the output of the security machine and obtains the encryption sequence S required to calculate the current frequency hopping pattern. enc .

[0080] 3) Simulate the air interface message frame structure:

[0081] After obtaining network time, frequency hopping library number, network number, encryption sequence and other parameters, network members can add time information and channel information to the extended header of the simulated air interface message, that is, the extended header contains two parts: time header and channel header. The frame structure design of the simulated air interface message is as follows: Figure 7 As shown, the extended simulated air interface message includes an extended header and a service part (the service part includes a service header and service content). The time header designed in this embodiment includes time information such as the time element number, the time frame number, and the time slot number, indicating the network time of sending the simulated air interface message; the channel header includes channel information such as the frequency hopping library number, the network number, and the encryption sequence, indicating the channel parameters for sending the simulated air interface message. Figure 7 The simulated air interface message frame structure is designed, and the extended header includes two parts: a time header and a channel header. The time header includes time information such as the time element, time frame, and time slot number, indicating the network time of sending the simulated air interface message; the channel header includes channel information such as the frequency hopping library number, network number, and encryption sequence, indicating the channel parameters for sending the simulated air interface message. Using the simulated air interface message based on the extended header of this embodiment can avoid the simulation of complex transmission waveforms, and can also achieve time and channel isolation, thereby realizing the simulation of multiple subnets of the frequency hopping TDMA synchronous orthogonal network.

[0082] refer to Figure 8 When the networking protocol module of the sender receives the network time, it determines whether the next time slot is a local transmission time slot according to the time slot table. If it is not a local transmission time slot, the processing ends; on the contrary, if it is a local transmission time slot, the interface processing module will package the service message to be sent in the time slot. When packaging the service message, first obtain the network time, frequency hopping library number, network number, encryption sequence and other parameters according to the previous section, and then add the extended header, that is, add the time element, time frame and time slot number indicating the transmission of the service data before the service header, as well as the frequency hopping library number, network number and encryption sequence used by the physical layer when sending the package service message.

[0083] refer to Fig. 9 When the receiving party's networking protocol module receives the service message reported by the Ethernet port, it parses the time element, time frame and time slot number, frequency hopping library number, network number and encryption sequence in the extended header. According to the previous section, the network time, frequency hopping library number, network number, encryption sequence and other parameters are obtained, and compared with the channel parameters in the extended header of the received service message. If the time slot in the time slot table is a local sending time slot or the channel parameters are inconsistent after comparison, it is judged as a sending and receiving conflict, and the networking protocol module directly discards the service message; on the contrary, if the time slot is not a local sending time slot and the channel parameters obtained locally are consistent with the channel parameters in the extended header, it can be received and processed normally.

[0084] refer to Fig.10In this embodiment, multiple synchronous orthogonal subnets (different subnets use different channels) can be simulated. After the simulation is completed, the performance indicators such as the throughput and end-to-end delay of each network are counted and obtained. The simulation steps are as follows: Fig.10 As shown, the details are as follows:

[0085] 1) Plan the frequency hopping library number, network number and time slot table used by each subnet and generate a network planning file;

[0086] 2) Set the total number of simulated nodes according to the number of members of each subnet to be simulated. Figure 5 Set up the connection relationship between each node and the switching device, configure the IP address, port number, etc. of each node, and ensure that each node is connected to each other;

[0087] 3) Set the channel parameters and time slot table of each node according to the network planning file, ensure that the nodes belonging to the same subnet use the same channel parameters and time slot table, and set the network simulation to start running;

[0088] 4) After the network simulation runs for the required time, set the simulation to end and count the performance indicators such as throughput and end-to-end delay of each subnet in turn.

[0089] Optionally, this embodiment adopts fixed access when introducing the time slot usage method, that is, the time slot is allocated to a certain network member for use, and other network members cannot use it. This embodiment also supports the use of time slots with competitive access, that is, the time slot is allocated to all network members for use, and each network member competes for use according to preset rules. The extended header designed in this embodiment includes a time header and a channel header, and the specific content contained in the two parts of the header can be modified according to the waveform system to be simulated. This embodiment is mainly suitable for the simulation of frequency-hopping TDMA synchronous orthogonal networks, and is also applicable to networks where network members maintain time synchronization and signals are not strictly orthogonal.

[0090] The beneficial effects of the present invention are as follows:

[0091] The present invention realizes virtual physical isolation by adding a time header and a channel header to air interface messages, avoids the influence of frequency hopping library numbers, network time, network numbers, and encryption sequences, reduces interference between network members, and solves the problems of difficulty in realizing transmission waveforms and difficulty in ensuring synchronous orthogonality.

[0092] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0093] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A frequency hopping time division multiple access synchronous orthogonal network simulation method, characterized in that: include: When the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, the frequency hopping library number, the network number and the encryption sequence are obtained; Calculate a frequency hopping pattern according to the network time, the frequency hopping library number, the network number and the encryption sequence to obtain an original air interface message; Adding a time header and a channel header to the original air interface message to obtain a simulated air interface message; The time header includes: time unit number, time frame number and time slot number; the channel header includes: frequency hopping library number, network number and encryption sequence; Sending the simulated air interface message to a switching device through an Ethernet port, and broadcasting the simulated air interface message to a synchronous orthogonal network using the switching device; After receiving the simulated air interface message, the networking protocol module of the receiver parses the extended header of the simulated air interface message to obtain the time header and the channel header; When the time slot numbers in the time header and the preset extension header are inconsistent and the channel parameters in the channel header and the preset extension header are consistent, the simulated air interface message is received.

2. A frequency hopping time division multiple access synchronous orthogonal network simulation method according to claim 1, characterized in that: The calculation formula of the frequency hopping pattern is: m,n =F(t TON ,I lib ,I net ,S enc );f m,n is the frequency point at which the network member sends the RF signal on the nth channel in the mth time slot; F(·) is the nonlinear transformation function; t TON is the network time; lib is the frequency hopping library number; net is the network number; S enc is the encryption sequence.

3. A frequency hopping time division multiple access synchronous orthogonal network simulation method according to claim 1, characterized in that: When the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, frequency hopping library number, network number and encryption sequence are obtained, including: Setting a network member as a time master, and setting network members other than the time master as time slaves; Using the time master to periodically send service messages; receiving the service message from the station using the time; The local time of the time slave station is adjusted according to the service message, and the local time is determined as the network time.

4. A frequency hopping time division multiple access synchronous orthogonal network simulation method according to claim 1, characterized in that: When the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, frequency hopping library number, network number and encryption sequence are obtained, including: Preset a network planning file and send the network planning file to all network members; The network planning file is parsed to obtain the frequency hopping library number and the network number.

5. A frequency hopping time division multiple access synchronous orthogonal network simulation method according to claim 3, characterized in that: When the networking protocol module of the sender determines that the next time slot is a local transmission time slot, the network time, the frequency hopping library number, the network number and the encryption sequence are obtained, and the following steps are also included: When the network time is determined, the network time is sent to a preset security machine; The encryption sequence is generated using the encryption engine according to the network time.

6. A frequency hopping time division multiple access synchronous orthogonal network simulation method according to claim 3, characterized in that: The service message is transmitted using a preset frequency hopping pattern.

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