Communication method and device

Abstract

The application is suitable for the field of traffic communication technology, and provides a communication method, comprising: a master device initiating a frame management time slot of a wireless frame, and broadcasting time slot allocation related information to a slave device in a communication area of the master device in the frame management time slot, wherein the wireless frame comprises the frame management time slot, a downlink packet data time slot and an uplink packet data time slot; and the master device and the slave device respectively send communication content in corresponding time slots of the wireless frame based on the time slot allocation related information, and the communication content is used for communication between the master device and the slave device. The application can realize orderly communication between the master device and the slave device, can avoid network congestion caused by multiple slave devices competing for network resources of the master device, and is helpful to realize stable and reliable communication between the master device and the slave device in the communication area of the master device.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of traffic communication, and particularly relates to a communication method and device. BACKGROUND

[0002] In the existing communication technology, when a master device and a slave device perform wireless communication, the slave device usually acquires wireless network resources of the master device in a resource self-competition manner.

[0003] In the related technology, the more the number of accessed slave devices, the more likely network congestion or even blockage occurs, resulting in unstable communication between the master device and the slave device. SUMMARY

[0004] Embodiments of the present application provide a communication method and device, aiming at solving the problem in the related technology that the more the number of accessed slave devices, the more likely network congestion or even blockage occurs, resulting in unstable communication between the master device and the slave device.

[0005] In a first aspect, an embodiment of the present application provides a communication method, which comprises:

[0006] The master device initiates a frame management time slot of a wireless frame, and broadcasts time slot allocation related information to a slave device in a communication area of the master device in the frame management time slot, wherein the wireless frame comprises the frame management time slot, a downlink packet data time slot and an uplink packet data time slot.

[0007] The master device and the slave device respectively send communication content in corresponding time slots of the wireless frame based on the time slot allocation related information, and the communication content is used for communication between the master device and the slave device.

[0008] Further, the wireless frame further comprises a random access time slot.

[0009] The random access time slot is used for the target slave device to send an access request to the master device, the access request is used to request the master device to allocate a resource time slot to the target slave device in a next wireless frame, the resource time slot comprises at least one of the downlink packet data time slot and the uplink packet data time slot, and the target slave device is a slave device in the communication area of the master device which is not allocated the resource time slot.

[0010] Further, the master device and the slave device respectively send communication content in corresponding time slots of the wireless frame based on the time slot allocation related information, comprising:

[0011] If the time slot allocation related information indicates that there are multiple random access time slots, the target slave device can send the access request to the master device in any one of the multiple random access time slots.

[0012] Further, the master device and the slave device respectively transmit communication contents in corresponding time slots of the wireless frame based on the time slot allocation related information, including:

[0013] If the time slot allocation related information indicates that the master device is allocated with a downlink packet data time slot for the slave device, the master device transmits the communication contents for the corresponding slave device to the corresponding slave device in the corresponding downlink packet data time slot.

[0014] Further, the master device and the slave device respectively transmit communication contents in corresponding time slots of the wireless frame based on the time slot allocation related information, including:

[0015] For each slave device within the communication area of the master device, if the time slot allocation related information indicates that the slave device is allocated with an uplink packet data time slot, the slave device transmits the communication contents to the master device in the corresponding uplink packet data time slot.

[0016] Further, each slave device within the communication area of the master device can receive the communication contents transmitted by the master device in the following manner:

[0017] The slave device determines a listening start time of the downlink packet data time slot for the slave device according to the time slot allocation related information, and starts to listen to the communication contents transmitted by the master device to the slave device at the determined listening start time, wherein the listening start time is close to and earlier than an arrival time of the downlink packet data time slot.

[0018] Further, the master device is a road side unit, and the slave device is a vehicle-mounted unit.

[0019] Further, the data structure of the communication contents in each time slot in the wireless frame includes: a preamble part and a data part, the preamble part includes a short sequence and a long sequence connected in sequence;

[0020] The long sequence corresponding to the frame management time slot is a first long sequence, the long sequence corresponding to the time slot other than the frame management time slot in the wireless frame is a second long sequence, and the first long sequence and the second long sequence are in an orthogonal relationship.

[0021] In a second aspect, an embodiment of the present application provides a master device, including:

[0022] The radio frequency transceiver is configured to broadcast time slot allocation related information to slave devices within a communication area of the master device in a frame management time slot of a wireless frame initiated by the master device, transmit communication contents to the slave devices in corresponding time slots of the master device, and receive communication contents transmitted by the slave devices in corresponding time slots of the slave devices, wherein the wireless frame includes the frame management time slot, a downlink packet data time slot and an uplink packet data time slot, and the communication contents are used for communication between the master device and the slave devices.

[0023] The processor is configured to initiate a frame management time slot of a wireless frame, and determine a corresponding time slot of the master device in the wireless frame and a corresponding time slot of the slave device in the wireless frame based on the time slot allocation related information.

[0024] In a third aspect, an embodiment of the present application provides a slave device, comprising:

[0025] The radio frequency transceiver is configured to receive time slot management information broadcast by the master device in the frame management time slot of the wireless frame, receive communication content sent by the master device in the corresponding time slot shared by the master device and the slave device, and send the communication content to the master device in the corresponding time slot of the slave device, wherein the wireless frame comprises the frame management time slot, a downlink packet data time slot and an uplink packet data time slot, and the communication content is used for communication between the master device and the slave device.

[0026] The processor is configured to determine a corresponding time slot of the master device in the wireless frame and a corresponding time slot of the slave device in the wireless frame based on the time slot allocation related information.

[0027] Compared with the related art, the embodiment of the present application has the beneficial effects that the master device allocates time slots for communication to the master device and the slave device through the wireless frame, the master device and the slave device can send communication content in the respective allocated time slots, orderly communication between the master device and the slave device is realized, network congestion caused by multiple slave devices competing for network resources of the master device can be avoided, and stable and reliable communication of the slave device in the communication area of the master device is facilitated.

[0028] It can be understood that the beneficial effects of the above-mentioned second aspect to the third aspect can be referred to the related description in the first aspect, and will not be described here again. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or related technical description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0030] Figure 1 is a flowchart of a communication method provided by an embodiment of the present application;

[0031] Figure 2 is a structure diagram of a wireless frame provided by an embodiment of the present application;

[0032] Figure 3 is a timing diagram of communication between a master device and a slave device provided by an embodiment of the present application;

[0033] Figure 4is a schematic diagram of a communication method provided by an embodiment of the present application applied to a highway information communication scenario;

[0034] Figure 5 is a data structure schematic diagram of communication content of each time slot provided by another embodiment of the present application;

[0035] Figure 6 is a flow schematic diagram of receiving communication content of each time slot by a receiving device of a master device or a slave device provided by an embodiment of the present application;

[0036] Figure 7 is a structure schematic diagram of a master device provided by an embodiment of the present application;

[0037] Figure 8 is a structure schematic diagram of a slave device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0038] In the following description, specific details are set forth, such as particular system configurations, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. However, persons skilled in the art will understand that the present application can be practiced without these specific details. In other instances, well-known structures, devices, circuits, and methods have not been described in detail in order to avoid obscuring the description of the present application.

[0039] It should be understood that the term "comprises" as used in the specification and the appended claims indicates the presence of the described features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0040] It should also be understood that the term "and / or" as used herein refers to any one of the associated listed items, combinations of one or more of the associated listed items, and all possible combinations thereof.

[0041] As used in the description of the application and the appended claims, the term "if' can be interpreted as meaning "when" or "once" or "in response to a determination" or "in response to a detection" depending on the context. Similarly, the phrase "if determined" or "if detected [the described condition or event]" can be interpreted as meaning "once determined" or "in response to a determination" or "once detected [the described condition or event]" or "in response to a detection [the described condition or event]" depending on the context.

[0042] In addition, in the description of the present application and the appended claims, the terms "first", "second", "third", etc. are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0043] Reference within the specification to "one embodiment" or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase "in one embodiment" or "in some embodiments" in various places within the specification are not necessarily all referring to the same embodiment, however, are meant to signify that "one or more, but not all embodiments" of the application so described are contemplated to

[0044] In order to illustrate the technical solutions of the present application, the following examples are used for illustration.

[0045] Please refer to Figure 1 The embodiment of the present application provides a communication method, comprising:

[0046] Step 101, the master device initiates a frame management slot of a wireless frame, and broadcasts time slot allocation related information to the slave device in the communication area of the master device in the frame management slot.

[0047] Wherein, the wireless frame can include time-continuous frame management slot (FMS), downlink packet data slot (DL-PDS) and uplink packet data slot (UL-PDS). FMS is the first slot of the wireless frame. In practical application, FMS in each wireless frame usually has only one, DL-PDS can have a first number, UL-PDS can have a second number, the first number and the second number can be the same or different. The above-mentioned communication area usually refers to the signal coverage area.

[0048] Wherein, the above-mentioned time slot allocation related information is usually information for describing the allocation of each slot in the wireless frame. For example, the time slot allocation related information can indicate that there are 2 DL-PDS and 3 UL-PDS, and can indicate that the first DL-PDS is used for the master device to send communication content to the slave device 1, the second DL-PDS is used for the master device to send communication content to the slave device 2, the first UL-PDS is used for the slave device 1 to send communication content to the master device, and the second-3 UL-PDS is used for the slave device 2 to send communication content to the master device.

[0049] Here, the master device can generate the time slot allocation related information, and then broadcast the time slot allocation related information to the slave devices in the communication area of the master device through the FMS of the wireless frame in a broadcast manner, so that the master device controls the orderly communication between the master device and the slave devices through the time slot allocation related information.

[0050] In practice, the master device can generate the time slot allocation related information according to the number of the slave devices in the current communication area, the device identifiers of the slave devices, the channel occupancy rate, and the like. As an example, the master device can generate the time slot allocation related information using the device identifiers of the slave devices when the channel occupancy rate is less than a preset occupancy threshold.

[0051] It should be noted that the two adjacent wireless frames can be continuous in time or discontinuous.

[0052] In actual application, the master device can determine whether to initiate a new wireless frame according to the network deployment and the related configuration, and the like. As an example, the master device can continuously initiate a new wireless frame according to the configuration, or discontinuously initiate a new wireless frame every time interval of the configured time length.

[0053] In step 102, the master device and the slave devices respectively transmit communication content in the corresponding time slots of the wireless frame based on the time slot allocation related information, and the communication content is used for the communication between the master device and the slave devices.

[0054] Here, after the master device broadcasts the time slot allocation related information in the FMS of the wireless frame, the master device can determine one or more DL-PDSs allocated to the master device and the slave devices pointed to by the DL-PDSs according to the time slot allocation related information, so that the master device can transmit the communication content to the corresponding slave devices in the DL-PDSs. In addition, after the slave device receives the time slot allocation related information, the slave device can determine one or more UL-PDSs allocated to the slave device according to the time slot allocation related information, so that the slave device can transmit the communication content to the master device in the corresponding UL-PDS. It should be noted that if there are multiple UL-PDSs allocated to a slave device, the multiple UL-PDSs are multiple UL-PDSs continuous in time.

[0055] The method provided by the embodiment can allocate time slots for the communication of the master device and the slave devices through the wireless frame, the master device and the slave devices can transmit the communication content in the respectively allocated time slots, and the orderly communication between the master device and the slave devices is realized, so that the network congestion caused by the competition of the master device network resources by multiple slave devices can be avoided, and the stable and reliable communication between the master device and the slave devices in the communication area of the master device can be facilitated.

[0056] It should be noted that the application is based on the existing Wi-Fi physical layer technology, introduces the master device as the scheduling center management mode, improves the unordered resource competition mode to the ordered wireless frame timing structure by redesigning the media access control (MAC) packet mode and adjusting the physical frame structure, and achieves the purposes of stable low latency and high reliability.

[0057] In optional implementation of various embodiments of the application, the wireless frame can further include a random access slot (RAS).

[0058] The RAS is used for the target slave device to send an access request to the master device, and the access request is used to request the master device to allocate a resource slot to the target slave device in the next wireless frame, and the resource slot includes at least one of the UL-PDS and the DL-PDS, and the target slave device is a slave device in the communication area of the master device that is not allocated a resource slot.

[0059] Here, the RAS is usually a slot located at the end of the wireless frame, and in a wireless frame, there can be one RAS, multiple RASs, or no RAS, and the specific number of RASs is usually allocated and implemented by the master device through time slot allocation related information. In addition, the number of UL-PDSs, the number of DL-PDSs, and the number of RASs can be different in every two wireless frames. In actual application, the number of UL-PDSs, DL-PDSs, and RASs in each wireless frame is usually determined by the master device in combination with the pre-set allocation rule and the actual communication scene requirement.

[0060] Figure 2 The structure of the wireless frame provided by the embodiment of the application is shown in the following table. Figure 2 The wireless frame in the table has m+n+k+1 slots, wherein the first slot is FMS, there are m DL-PDSs after the FMS, there are n UL-PDSs after the m DL-PDSs, and there are k RASs after the n UL-PDSs. Figure 2 Each two adjacent slots in the table are continuous in time.

[0061] It should be noted that the RASs in the wireless frame can realize on-demand allocation of resource slots to slave devices that are not allocated resource slots. The two allocation modes of active allocation of resource slots by the master device and request allocation of resource slots by the slave device coexist, which helps the master device to allocate resource slots to the slave devices more flexibly.

[0062] In actual application, the slave device can request the master device to allocate resource time slots through RAS after entering the communication area of the master device and before being allocated resource time slots for the first time. After being allocated resource time slots, the slave device can actively communicate with the master device through the resource time slots. After being allocated resource time slots, the master device can dynamically allocate resource time slots to the slave device in subsequent wireless frames based on the communication requirement of the slave device.

[0063] In the above implementation, the master device and the slave device respectively transmit communication contents in corresponding time slots of a wireless frame based on the time slot allocation related information, including:

[0064] If the time slot allocation related information indicates that there are multiple random access time slots, the target slave device can send an access request to the master device in any of the multiple random access time slots.

[0065] The target slave device is a slave device in the communication area of the master device and not allocated resource time slots.

[0066] Here, after receiving the time slot allocation related information, the target slave device can learn the number of RAS in the current wireless frame by analyzing the time slot allocation related information, and then send an access request to the master device in any random access time slot. In actual application, if two or more first target devices simultaneously compete for the same RAS, the access request may be collided. In this case, the collided slave device can continue to initiate an access request in the RAS of the next frame. It should be noted that since the number of target slave devices in the communication area of a certain master device is usually not large, the collision probability of the access request is usually very small, and stable communication between the master device and the slave devices in the communication area of the master device can still be ensured.

[0067] Figure 3 A timing diagram of communication between a master device and a slave device provided by an embodiment of the present application. Figure 3 In the timing diagram, Frame1 is the first wireless frame of communication between the master device and the slave device, Frame2 is the second wireless frame, and Frame3 is the third wireless frame.

[0068] In the first wireless frame, the master device broadcasts time slot allocation related information to the slave device through FSM. The slave device is a slave device not allocated resource time slots. At this time, the slave device can send an access request to the master device through RSA to request the master device to allocate resource time slots to the slave device in the next wireless frame.

[0069] In the second radio frame, the master device broadcasts the time slot allocation related information to the slave device, the slave device is allocated with a resource time slot, specifically, the slave device is allocated with a DL-PDS for the slave device to receive communication content and a UL-PDS for the slave device to send communication content to the master device. At this time, the master device sends data resource to the slave device in the DL-PDS, and the slave device sends information for confirming successful reception of the data resource to the master device in the UL-PDS.

[0070] In the third radio frame, the master device broadcasts the time slot allocation related information to the slave device, and the master device and the slave device respectively send communication content in corresponding time slots of the radio frame based on the time slot allocation manner indicated by the time slot allocation related information. The following radio frames are similar.

[0071] In the optional implementation of the various embodiments of the present application, the above-mentioned master device and the slave device respectively send communication content in corresponding time slots of the radio frame based on the time slot allocation related information, which can include:

[0072] If the time slot allocation related information indicates that the master device is allocated with a DL-PDS for the slave device, the master device sends communication content for the corresponding slave device to the corresponding slave device in the corresponding DL-PDS.

[0073] Here, the master device can obtain one or more DL-PDSs and the slave devices pointed to by the DL-PDSs according to the indication of the time slot allocation related information, so that the master device can send communication content to the corresponding slave device in turn according to the time sequence of the DL-PDSs.

[0074] In the optional implementation of the various embodiments of the present application, the master device and the slave device respectively send communication content in corresponding time slots of the radio frame based on the time slot allocation related information, which includes:

[0075] For each slave device in the communication area of the master device, if the time slot allocation related information indicates that the slave device is allocated with a UL-PDS, the slave device sends communication content to the master device in the corresponding UL-PDS.

[0076] Here, each slave device can send communication content to the master device in one or more UL-PDSs allocated correspondingly.

[0077] In the optional implementation of the various embodiments of the present application, each slave device in the communication area of the master device can receive the communication content sent by the master device in the following way:

[0078] The slave device determines the listening start time of the DL-PDS for the slave device according to the time slot allocation related information, and starts to listen to the communication content sent by the master device to the slave device at the determined listening start time.

[0079] The listening start time is close to and earlier than the arrival time of the DL-PDS. The listening start time is usually the time for starting listening.

[0080] In actual application, since the time length occupied by each time slot is usually fixed, such as 1 millisecond, the slave device can determine the arrival time of the DL-PDS for the slave device based on the time slot allocation related information. Then, the slave device can start the listening function before the arrival time, so as to receive the communication content sent by the master device to the slave device. In practice, the listening start time is usually earlier than the arrival time by the time length corresponding to one time slot.

[0081] Here, after the FSM, before the DL-PDS for the slave device arrives, the slave device can be in a low-power-consumption state, such as a sleep state, so that the power consumption of the device can be reduced.

[0082] In the optional implementation of each embodiment of the present application, the master device is a Roadside Unit (RSU), and the slave device is an On Board Unit (OBU). There is at least one RSU, and there is at least one OBU in the communication area of each RSU.

[0083] It should be noted that when the master device is an RSU and the slave device is an OBU, the method provided by the present application can be applied to the field of highway information communication. When the RSU is the master device, the communication area can reach several hundred or even thousands of meters. A small number of RSUs can be used to manage a large number of OBUs. This helps to reduce the communication cost of communication between the RSU and the OBU.

[0084] Figure 4 The communication method provided by the embodiments of the present application is applied to the schematic diagram of the highway information communication scene. As shown in Figure 4 The RSU is deployed on the highway gantry, and the distance between every two gantries can reach more than 1 kilometer. Each vehicle corresponds to an OBU. There can be one or more OBUs in each lane within the RSU coverage area. Figure 4 In the figure, there are four OBUs in the RSU coverage area, which are OBU1, OBU2, OBU3 and OBU4.

[0085] In the application scenario, the RSU as the master device usually broadcasts the information related to the time slot allocation of the FSM and coordinates all the OBUs in the coverage area for resource scheduling. The OBU as the slave device can request access or request resources. The RSU can realize the functions of broadcast or unicast by configuring the IP address of the MAC frame header. Through the functions, the RSU can broadcast the road condition information to all the OBUs in the coverage area or issue instructions to specific OBUs. The OBU can apply for wireless resources for downloading and uploading data packets and the like in the access state.

[0086] In the optional implementation of various embodiments of the present application, the data structure of the communication content of each time slot in the wireless frame comprises a preamble part and a data part, and the preamble part comprises sequentially connected short sequences and long sequences.

[0087] The long sequence corresponding to the FMS is a first long sequence, the long sequence corresponding to the time slot other than the FMS in the wireless frame is a second long sequence, and the first long sequence and the second long sequence are in an orthogonal relationship.

[0088] In actual application, the communication content of each time slot usually needs to follow a preset data structure.

[0089] Figure 5 The data structure of the communication content of each time slot provided by the embodiments of the present application is shown in the figure. Figure 5 In the shown data structure, the short sequences, the long sequences and the data part are sequentially arranged.

[0090] In actual application, the short sequence can be: {0, 0, 1+j, 0, 0, 0, -1-j, 0, 0, 0, 1+j, 0, 0, 0, -1-j, 0, 0, 0, -1-j, 0, 0, 0, 1+j, 0, 0, 0, 0, 0, 0, 0, -1-j, 0, 0, 0, -1-j, 0, 0, 0, 1+j, 0, 0, 0, 1+j, 0, 0, 0, 1+j, 0, 0, 0, 1+j, 0, 0}.

[0091] The first long sequence can be: {1, 1, -1, -1, 1, 1, -1, 1, -1, 1, 1, 1, 1, 1, 1, -1, -1, 1, 1, -1, 1, -1, 1, 1, 1, 1, 0, 1, -1, -1, 1, 1, -1, 1, -1, 1, -1, -1, -1, -1, -1, 1, 1, -1, -1, 1, -1, 1, -1, 1, 1, 1, 1}.

[0092] The second long sequence can be: {1, 1, 1, 1, -1, 1, -1, 1, -1, -1, 1, 1, -1, -1, -1, -1, -1, 1, -1, 1, -1, 1, 1, -1, -1, 1, 0, 1, 1, 1, 1, -1, 1, -1, 1, 1, -1, -1, 1, 1, 1, 1, 1, 1, -1, 1, -1, 1, 1, -1, -1, 1, 1}.

[0093] It should be noted that the second long sequence can also be other sequences orthogonal to the first long sequence, and the embodiment is not limited specifically.

[0094] Here, the long sequence corresponding to the FSM is different from the long sequence corresponding to other time slots, which can facilitate the slave device to accurately identify the data of the FSM and the data of the non-FSM. In addition, the first long sequence and the second long sequence are in an orthogonal relationship, which can more quickly and accurately identify the first long sequence and the second long sequence, thereby helping to further improve the accurate identification of the data of the FSM and the data of the non-FSM by the slave device.

[0095] It should be noted that the master device or the slave device usually needs to process the communication content of each time slot into baseband time domain data convenient for the transmitting device to transmit before transmitting the communication content. In addition, the transmitting device can transmit the baseband time domain data of each time slot through the radio frequency port after frequency up-conversion.

[0096] Specifically, the transmitting device can process the communication content of the time slot into baseband time domain data convenient for the transmitting device to transmit by performing the following steps:

[0097] First, the transmitting device performs Inverse Fast Fourier Transform (IFFT) on the short sequence to generate corresponding time domain data, the number of Fast Fourier Transform (FFT) points is 1 / 4, and then 10 cycles are copied to obtain time domain data corresponding to the short sequence. Here, the above operation of copying 10 cycles can realize sufficient time for power adaptation and frame header synchronization when the receiving device detects the frame header.

[0098] Then, the transmitting device selects according to the type of the time slot, if it is the FMS, the first long sequence is selected, and if it is the non-FMS, the second long sequence is selected. The transmitting device performs IFFT transform on the selected long sequence to generate corresponding time domain data, adds a half-length prefix and copies 2 cycles to obtain time domain data corresponding to the long sequence. Here, the long sequence can be used for frequency offset estimation, fine timing, etc.

[0099] Finally, the transmitting device converts the data in the data section into Orthogonal Frequency Division Multiplexing (OFDM) data symbols. The process of generating OFDM data symbols is completely consistent with the OFDM technology operation described in the IEEE 802.11-2016 standard, and will not be elaborated upon here.

[0100] It should be noted that the sequential combination of the time-domain data corresponding to the short sequence, the time-domain data corresponding to the long sequence, and the data symbols corresponding to the data portion constitutes the baseband time-domain data that is convenient for the transmitting device to transmit.

[0101] Figure 6 This is a schematic diagram illustrating the process by which a receiving device of a master or slave device, as provided in an embodiment of this application, receives communication content in each time slot.

[0102] like Figure 6 As shown, the receiving device may include the following steps 601-604 in receiving the communication content of each time slot.

[0103] Step 601: The receiving device starts listening.

[0104] Here, the receiving device can receive down-converted baseband time-domain data from the RF port in listening mode.

[0105] Step 602: The receiving device performs short sequence frame header detection.

[0106] Here, the receiving device can detect the coarse position of the frame header of the communication content of the time slot based on the short sequence of the preamble part.

[0107] Step 603: The receiving device performs long sequence frame header detection.

[0108] Here, the receiving device can detect the precise start position of the frame header of the communication content in the time slot based on the long sequence of the preamble portion.

[0109] Specifically, the receiving device may use a first long sequence to detect the precise start position of the FMS frame header and a second long sequence to detect the precise start position of the non-FMS frame header.

[0110] Here, coarse positioning and fine positioning are two relative concepts. The combination of short and long sequences can achieve accurate positioning of the frame header of the data transmitted in each time slot.

[0111] In practice, for each radio frame, the receiving device can perform a synchronization search using a first long sequence before detecting the FSM, and a second long sequence after detecting the FSM. This can improve data processing efficiency.

[0112] At step 604, the receiving device data-demodulates the data part to obtain valid communication data.

[0113] Here, the receiving device can take out data of corresponding length symbol by symbol after confirming the data symbol position, so as to obtain data transmitted in the corresponding time slot.

[0114] With reference to the foregoing Figure 7 The embodiment of the present application also provides a master device, comprising a radio frequency transceiver 701 and a processor 702, wherein,

[0115] The radio frequency transceiver 701 is used for broadcasting time slot allocation related information to a slave device in a communication area of the master device in a frame management time slot of a wireless frame initiated by the master device, transmitting communication content to the slave device in a corresponding time slot of the master device, and receiving communication content transmitted by the slave device in a corresponding time slot of the slave device, wherein the wireless frame comprises the frame management time slot, a downlink packet data time slot and an uplink packet data time slot, and the communication content is used for communication between the master device and the slave device;

[0116] The processor 702 is used for initiating the frame management time slot of the wireless frame, and determining the corresponding time slot of the master device in the wireless frame and the corresponding time slot of the slave device in the wireless frame based on the time slot allocation related information.

[0117] With reference to the foregoing Figure 8 The embodiment of the present application also provides a slave device, comprising a radio frequency transceiver 801 and a processor 802, wherein,

[0118] The radio frequency transceiver 801 is used for receiving time slot management information broadcasted by a master device in a frame management time slot of a wireless frame, receiving communication content transmitted by the master device in a corresponding time slot shared by the master device and the slave device, and transmitting communication content to the master device in a corresponding time slot of the slave device, wherein the wireless frame comprises the frame management time slot, a downlink packet data time slot and an uplink packet data time slot, and the communication content is used for communication between the master device and the slave device;

[0119] The processor 802 is used for determining the corresponding time slot of the master device in the wireless frame and the corresponding time slot of the slave device in the wireless frame based on the time slot allocation related information.

[0120] In the embodiment of the present application, the master device allocates time slots for communication to the master device and the slave device through the wireless frame, the master device and the slave device can transmit communication content in the respective allocated time slots, ordered communication between the master device and the slave device is realized, network congestion caused by multiple slave devices competing for network resources of the master device can be avoided, and stable and reliable communication between the master device and the slave device in the communication area of the master device is facilitated.

[0121] It should be noted that the information interaction between the master device and the slave device, the execution process, and the like, are based on the same concept as the method embodiments of the present application, and the specific functions and the resulting technical effects can be referred to the method embodiments part, which will not be repeated here.

[0122] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, device (system) or computer program product. Therefore, the present application can adopt a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0123] The present application is described with reference to flowcharts and / or block diagrams of the method, device (system) and computer program product of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0124] These computer program instructions can also be stored in a computer readable storage medium that can direct the computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer readable storage medium produce a manufactured product including instruction apparatus, which implements the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0125] These computer program instructions can also be loaded into a computer or other programmable data processing apparatus, so that a series of operation steps are performed on the computer or other programmable data processing apparatus to produce a computer implemented process, so that the instructions executed on the computer or other programmable data processing apparatus provide a process for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0126] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0127] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A communication method characterized by comprising: The method comprises: a master device initiating a frame management time slot of a wireless frame, and broadcasting time slot allocation related information to a slave device in a communication area of the master device in the frame management time slot, wherein the wireless frame comprises a frame management time slot, a downlink packet data time slot and an uplink packet data time slot, the master device is a road side unit, and the slave device is a vehicle-mounted unit; The master device and the slave device respectively transmit communication content in corresponding time slots of the wireless frame based on the time slot allocation related information, the communication content being used for communication between the master device and the slave device, wherein the master device or the slave device needs to process the communication content to be transmitted into baseband time domain data facilitating transmission before transmitting the communication content of each time slot; the wireless frame further comprises a random access time slot, which is a time slot located at the end of the wireless frame; The random access time slot is used for a target slave device to transmit an access request to the master device, the access request being used for requesting the master device to allocate a resource time slot to the target slave device in a next wireless frame, the resource time slot comprising at least one of the downlink packet data time slot and the uplink packet data time slot, and the target slave device being a slave device in the communication area of the master device and not being allocated a resource time slot; Each slave device in the communication area of the master device receives the communication content transmitted by the master device in the following manner: The slave device determines a listening start time of the downlink packet data time slot for the slave device according to the time slot allocation related information, and starts to listen to the communication content transmitted by the master device to the slave device at the determined listening start time, wherein the listening start time is close to and earlier than an arrival time of the downlink packet data time slot; The data structure of the communication content of each time slot in the wireless frame comprises a preamble part and a data part, and the preamble part comprises a short sequence and a long sequence connected in sequence; The long sequence corresponding to the frame management time slot is a first long sequence, the long sequence corresponding to a time slot other than the frame management time slot in the wireless frame is a second long sequence, and the first long sequence and the second long sequence are in an orthogonal relationship, wherein the long sequence corresponding to the frame management time slot is different from the long sequence corresponding to other time slots; The master device or the slave device receives the communication content of each time slot in the following manner: Receiving baseband time domain data; Performing short sequence frame header detection based on the short sequence of the preamble part to detect a frame header start coarse position of the communication content of the time slot; Performing long sequence frame header detection based on the long sequence of the preamble part to detect a frame header start fine position of the communication content of the time slot; Performing data demodulation on the data part to obtain effective communication data; The first long sequence is used to detect the frame header start fine position of the frame management time slot, and the second long sequence is used to detect the frame header start fine position of a non-frame management time slot.

2. The communication method according to claim 1, characterized by, The master device and the slave device respectively transmit communication content in corresponding time slots of the wireless frame based on the time slot allocation related information, If the time slot allocation related information indicates that there are multiple random access time slots, the target slave device can send the access request to the master device in any of the multiple random access time slots.

3. The communication method according to claim 1, wherein, The master device and the slave device each send communication content in the corresponding time slot of the wireless frame based on the time slot allocation related information, including: If the time slot allocation related information indicates that the master device is allocated with a downlink packet data time slot for a slave device, the master device sends communication content for the corresponding slave device to the corresponding slave device in the corresponding downlink packet data time slot.

4. The communication method according to claim 1, characterized by, The master device and the slave device each send communication content in the corresponding time slot of the wireless frame based on the time slot allocation related information, including: For each slave device within the communication area of the master device, if the time slot allocation related information indicates that the slave device is allocated with an uplink packet data time slot, the slave device sends communication content to the master device in the corresponding uplink packet data time slot.

5. A host device, comprising: including: The radio frequency transceiver is configured to broadcast time slot allocation related information to slave devices within the communication area of the master device in the frame management time slot of the wireless frame initiated by the master device, send communication content to the slave devices in the corresponding time slots of the master device, and receive communication content sent by the slave devices in the corresponding time slots of the slave devices, wherein the wireless frame includes a frame management time slot, a downlink packet data time slot, and an uplink packet data time slot, and the communication content is used for communication between the master device and the slave devices, wherein the master device needs to process the to-be-sent communication content into baseband time domain data convenient for transmission before sending out the communication content of each time slot; The processor is configured to initiate the frame management time slot of the wireless frame, and determine the corresponding time slot of the master device in the wireless frame and the corresponding time slot of the slave device in the wireless frame based on the time slot allocation related information. The wireless frame further includes a random access time slot, which is a time slot located at the end of the wireless frame. The random access time slot is used for a target slave device to send an access request to the master device, and the access request is used to request the master device to allocate a resource time slot to the target slave device in the next wireless frame, and the resource time slot includes at least one of a downlink packet data time slot and an uplink packet data time slot, and the target slave device is a slave device within the communication area of the master device that is not allocated with a resource time slot. Each slave device within the communication area of the master device receives the communication content sent by the master device in the following manner: The slave device determines a listening start time of the downlink packet data time slot for the slave device according to the time slot allocation related information, and starts to listen to the communication content sent by the master device to the slave device at the determined listening start time, wherein the listening start time is close to and earlier than the arrival time of the downlink packet data time slot; The data structure of the communication content of each time slot in the wireless frame includes a preamble part and a data part, and the preamble part includes a short sequence and a long sequence connected in sequence. The long sequence corresponding to the frame management time slot is a first long sequence, the long sequence corresponding to the time slot other than the frame management time slot in the radio frame is a second long sequence, and the first long sequence and the second long sequence are in an orthogonal relationship, wherein the long sequence corresponding to the frame management time slot is different from the long sequence corresponding to the other time slot. The master device receives the communication content of each time slot, including the following steps: Receiving baseband time domain data; Detecting the frame header start coarse position of the communication content of the time slot based on the short sequence of the preamble part to perform short sequence frame header detection; Detecting the frame header start fine position of the communication content of the time slot based on the long sequence of the preamble part to perform long sequence frame header detection; Data demodulation is performed on the data part to obtain effective communication data; The first long sequence is used to detect the frame header start fine position of the frame management time slot, and the second long sequence is used to detect the frame header start fine position of the non-frame management time slot.

6. A slave device, comprising: It includes: The radio frequency transceiver is used to receive the time slot management information broadcasted by the master device in the frame management time slot of the radio frame, receive the communication content sent by the master device in the corresponding time slot shared by the master device and the slave device, and send the communication content to the master device in the corresponding time slot of the slave device, wherein the radio frame includes a frame management time slot, a downlink packet data time slot, and an uplink packet data time slot, the communication content is used for communication between the master device and the slave device, and the slave device needs to process the to-be-sent communication content into baseband time domain data before sending out the communication content of each time slot; The processor is used to determine the corresponding time slot of the master device in the radio frame based on the time slot allocation related information, and determine the corresponding time slot of the slave device in the radio frame; The radio frame further includes a random access time slot, which is a time slot located at the end of the radio frame; The random access time slot is used for the target slave device to send an access request to the master device, the access request is used to request the master device to allocate a resource time slot to the target slave device in the next radio frame, the resource time slot includes at least one of the downlink packet data time slot and the uplink packet data time slot, and the target slave device is a slave device in the communication area of the master device which is not allocated a resource time slot; Each slave device in the communication area of the master device receives the communication content sent by the master device in the following way: The slave device determines the listening start time of the downlink packet data time slot for the slave device according to the time slot allocation related information, and starts listening to the communication content sent by the master device to the slave device at the determined listening start time, wherein the listening start time is close to and earlier than the arrival time of the downlink packet data time slot; The data structure of the communication content of each time slot in the radio frame includes a preamble part and a data part, and the preamble part includes a short sequence and a long sequence connected in sequence. The long sequence corresponding to the frame management time slot is a first long sequence, the long sequence corresponding to the time slot other than the frame management time slot in the radio frame is a second long sequence, and the first long sequence and the second long sequence are in an orthogonal relationship, wherein the long sequence corresponding to the frame management time slot is different from the long sequence corresponding to the other time slot. The step of receiving the communication content of each time slot by the slave device comprises the following steps: Receiving baseband time domain data; Detecting the frame header start coarse position of the communication content of the time slot based on the short sequence of the preamble part to perform short sequence frame header detection; Detecting the frame header start fine position of the communication content of the time slot based on the long sequence of the preamble part to perform long sequence frame header detection; Performing data demodulation on the data part to obtain effective communication data; The first long sequence is used to detect the frame header start fine position of the frame management time slot, and the second long sequence is used to detect the frame header start fine position of the non-frame management time slot.

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