Real-time data slicing method for OFDM-PON (orthogonal frequency division multiplexing-passive optical network) transmitting end

Abstract

The invention discloses an OFDM-PON (Orthogonal Frequency Division Multiplexing-Passive Optical Network) transmitting end data real-time slicing method, which comprises the following steps that: a data processing module of a transmitting end receives service data through a service interface module, and writes the service data into a data storage module of the transmitting end for subsequent reading; the data storage module sends a real-time data storage state to a decision-making layer; the decision-making layer sends control information to the data storage module and the data slicing module in each sending period; the data storage module reads the data stream to be sliced from the data slicing module in each sending period and sends data stream marking information; the data slicing module slices the data streams to be sliced according to the subcarrier mapping format message sent by the decision layer and the mark information and read data of all the data streams to be sliced sent by the data storage module, and sends the data streams to the parallel subcarrier interface; and remaining bit data of the slices in the period are registered in the to-be-sliced data storage area. According to the method, the flexibility of bandwidth allocation and the communication performance of the system are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of passive optical networks, and in particular to a real-time slicing method for OFDM-PON transmitting end data. Background Art

[0002] With the rapid development of Internet technology, the demand for data transmission has exploded, and modern networks have put forward higher requirements for data transmission. Traditional passive optical network (PON) technology, such as time division multiplexing passive optical network (TDM-PON), is difficult to achieve the flexible bandwidth allocation requirements of modern networks due to its time division multiplexing characteristics of allocating time slices to users on a single carrier. Orthogonal frequency division multiplexing passive optical network (OFDM-PON) maps multi-user data in the form of OFDM symbols on multiple carriers for communication. Its advantages such as high spectrum utilization, high flexibility in bandwidth allocation, and low latency and low jitter of services have attracted widespread attention and research.

[0003] At the transmitting end of OFDM-PON, it is necessary to complete the function of real-time allocation of service data from reception to each subcarrier in bit units according to the dynamic modulation format. The ITU-T G.989 protocol provides suggestions for the low jitter of 40Gbit / s NG-PON2 services from the perspective of network operators and dynamic bandwidth allocation, but it is not suitable for the scenario where OFDM-PON transmits service data at the bit level; KANG et al. provide a method and device for converting the MAC frame of the media access control (MAC) layer into a physical frame containing a physical layer preamble in "OFDM SIGNAL TRANSMITTING APPARATUS AND METHODFOR OFDM-PON [P]. KR20140127902, 2016-04-01." The patent implements signal transmission from the macroscopic processes such as data reception, OFDM symbol modulation, and subcarrier mapping, but does not describe in detail how to map data in the form of OFDM symbols to subcarriers for transmission at the bit level. Summary of the invention

[0004] In view of the fact that the existing technology cannot complete the reception, slicing, mapping and sending of OFDM-PON data at the bit level, the present invention provides a real-time slicing method for OFDM-PON transmitting end data, with a transmission period T of an OFDM symbol. send It is a time unit. By realizing real-time data slicing and subcarrier mapping, the whole process from receiving to sending business data is completed, thereby meeting the business needs of low latency and low jitter, while ensuring the flexibility of system bandwidth allocation and communication performance.

[0005] To achieve the above object, the present invention provides a real-time slicing method for OFDM-PON transmitting end data, comprising the following steps:

[0006] The data processing module of the OLT at the sending end receives the service data from the upper service layer through the service interface module, and writes the service data into the data storage module at the sending end, preparing for subsequent reading;

[0007] The data storage module transmits the data storage status in the data storage module to the decision layer in real time;

[0008] The decision-making layer sends the send Sending control information to the data storage module and the data slicing module;

[0009] The data storage module sends data in each transmission cycle T send The inward data slicing module reads the data stream to be sliced ​​and sends data stream marking information;

[0010] The data slicing module slices the data stream to be sliced ​​according to the subcarrier mapping format message sent by the decision layer and the marking information and read data of all the data streams to be sliced ​​sent by the data storage module, sends it to the parallel subcarrier interface, and stores the remaining bit data of the slice in this cycle in the data storage area to be sliced.

[0011] Furthermore, the data storage module receives the service data from the service interface module, and caches different areas according to different service destination addresses to form several data stream cache areas, each of which stores and reads data in sequence in a first-in-first-out queue.

[0012] Furthermore, the data storage module transmits the data storage status in the data storage module to the decision layer in real time, including the source address, destination address and data storage capacity of each service.

[0013] Furthermore, after the data storage module transmits the data storage status in the data storage module to the decision layer in real time, the decision layer first calculates the data reading information and sends it to the data storage module through the data storage status, bit error rate of each ONU, delayed communication status and upstream and downstream traffic status sent in real time by the data storage module, and then calculates the subcarrier mapping format message in this sending cycle k, and sends it to the data slicing module.

[0014] Furthermore, the data storage module and the data slicing module are connected.

[0015] Furthermore, the data storage module sends send The inbound data slicing module reads the data stream to be sliced ​​and sends data stream marking information, including:

[0016] The data storage module reads the data sent by the decision layer in the current sending cycle k, calculates the marking information of each data stream to be sliced, and reads the marking information and sends it to the data slicing module in parallel.

[0017] Furthermore, the data storage module reads the data sent by the decision layer in the current sending cycle k. Calculate the tag information of each data stream to be sliced And read the data Send to the data slicing module in parallel;

[0018] in, is a binary symbol, indicating that the data read from data stream i in this sending cycle k is valid. is a bit identifier indicating the number of valid data bits read from data stream i in the current sending cycle k.

[0019] Furthermore, the data slicing module follows the subcarrier mapping format message sent by the decision layer, and i∈[1,N],l∈[1,M].

[0020] in, Indicates the number of data bits carried by the modulation format adopted by subcarrier l in this transmission cycle k, Indicates that in the kth transmission cycle, the ONU carried by subcarrier l is ONU i . Further, the data slicing module slices the data stream to be sliced ​​according to the subcarrier mapping format message sent by the decision layer and the marking information and read data of all the data streams to be sliced ​​sent by the data storage module, sends it to the parallel subcarrier interface, and stores the remaining bit data of the slices in this cycle in the data storage area to be sliced, specifically including:

[0021] Before slicing, the slicing information of each data stream is extracted through the subcarrier mapping format message, and the length of the data to be sliced ​​is calculated;

[0022] Before slicing, firstly, for each data stream to be sliced, check whether there is residual data of the data stream in the previous slicing process in the data storage area to be sliced, if there is, extract the corresponding residual data and count the number of bits of the residual data; through the marking information of all the data streams to be sliced, the read data of each data stream is spliced ​​and stored to form the data to be sliced;

[0023] Compare the length of the data to be sliced ​​with the length of the spliced ​​data. When the length of the spliced ​​data is greater than or equal to the length of the data to be sliced, it means that the data of the data stream i in this sending cycle has been fully spliced, and data slicing is performed;

[0024] The data slicing module allocates bits of the data to be sliced ​​through the subcarrier mapping format message, and allocates them to the specified subcarriers according to the binary sequence obtained by parsing, and stores the remaining bit data in the slicing period in the corresponding area in the data storage area to be sliced.

[0025] Furthermore, when each data stream is spliced, the remaining data is spliced ​​first, and then the remaining data of the data stream in the data cache module is spliced, and the length of the spliced ​​data is calculated.

[0026] Technical Effects

[0027] 1. The present invention provides a real-time data slicing method for an OFDM-PON transmitter, which can meet the needs of the OFDM-PON transmitter from receiving services to sending on the subcarrier interface at the bit level, meet the service requirements for low latency and low jitter, ensure the flexibility of system bandwidth allocation and communication performance, and meet the optimal communication conditions of each ONU during their respective communications.

[0028] 2. The present invention ensures stable transmission of the data link by performing real-time data slicing and subcarrier mapping at the transmitting end, solves the problems of low resource utilization and inability to adapt to the traditional TDM-PON in dynamic rate scenarios, and gives full play to the flexibility and bandwidth advantages of the OFDM-PON system. In one transmission cycle, the minimum N*M*B min (bit / s) to N*M*B max Flexible rate transmission (bit / s).

[0029] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of a method for real-time slicing of data at an OFDM-PON transmitting end according to a preferred embodiment of the present invention;

[0031] Figure 2 It is a schematic diagram of a slicing process of a data slicing module of a real-time data slicing method of an OFDM-PON transmitting end according to a preferred embodiment of the present invention;

[0032] Figure 3 This is a system architecture diagram of a real-time data slicing method for an OFDM-PON transmitter according to a preferred embodiment of the present invention;

[0033] Figure 4It is a simulation result diagram of a data slicing module of a real-time data slicing method of an OFDM-PON transmitting end according to a preferred embodiment of the present invention, extracting slicing information of each data stream through a subcarrier mapping format message;

[0034] Figure 5 It is a simulation result diagram of data splicing and splicing length calculation of a real-time data slicing method of an OFDM-PON transmitter in a preferred embodiment of the present invention;

[0035] Figure 6 This is a simulation result diagram comparing the length of data to be sliced ​​and the length of spliced ​​data in a real-time data slicing method at an OFDM-PON transmitter of a preferred embodiment of the present invention;

[0036] Figure 7 This is a diagram of simulation results of bit allocation of data to be sliced ​​in a real-time slicing method for OFDM-PON transmitting end data according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0038] In the following description, specific details such as specific internal procedures and techniques are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0039] like Figure 1 As shown, the overall flow chart of a real-time slicing method for OFDM-PON transmitting end data provided by the present invention is applied in the field of passive optical network technology, and comprises the following steps:

[0040] S101: The data processing module of the OLT at the transmitting end receives the service data from the upper service layer through the service interface module, and writes the service data into the data storage module at the transmitting end, preparing for subsequent reading; the data storage module receives the service data from the service interface module, and caches different areas according to different service destination addresses to form a number of data stream cache areas, each of which is stored and read out in order in a first-in-first-out queue.

[0041] S102: The data storage module transmits the data storage status in the module to the decision layer in real time; the data storage module sends the data storage information to the decision layer in real time, including the source address, destination address and data storage capacity of each business.

[0042] S103: The decision layer sends a message in each sending cycle T send The inward data storage module and the data slicing module send control information; the decision layer first calculates the data reading information through the data storage status, the bit error rate, delay and other communication conditions of each ONU and the upstream and downstream traffic conditions sent in real time by the data storage module And send it to the data storage module, and then calculate the subcarrier mapping format message in this sending cycle k and i∈[1,N],l∈[1,M], and sent to the data slicing module.

[0043] Where N is the maximum number of ONUs, i is the sequence number of a data stream, M is the total number of subcarriers, and l is the sequence number of a subcarrier. is the number of data bits that need to be read out of the data stream sent to the i-th destination address in the k-th sending cycle; is the number of data bits carried by the modulation format adopted by subcarrier 1 in the kth transmission cycle. Indicates that in the kth transmission cycle, subcarrier l carries ONU i This message is used to inform the data slice module of the mapping relationship between each data stream and each subcarrier. The number of modulation bits should be within the modulation bit range supported by the system [B min ,B max ]Inside.

[0044] S104: The data storage module sends data in each transmission cycle T send The inward data slicing module reads the data stream to be sliced ​​and sends the data stream tag information; the data storage module is connected to the data slicing module, and in each sending cycle T send The inbound data slicing module reads the data stream to be sliced ​​and the data stream tag information. The specific operations include:

[0045] The data storage module reads information from the data sent by the decision layer in this sending cycle k. Calculate the tag information of each data stream to be sliced And read the data Sent to the data slicing module in parallel.

[0046] in, It is a binary symbol, indicating that the data read from data stream i in the current sending cycle k is valid. is a bit identifier indicating the number of valid bits of data read from data stream i in this sending cycle k, and its bit width is Indicates the data bus width D BW Take the logarithm of 2, round down, and add 1. Before the last clock tick On the last clock tick, % is the remainder operation. The data read out from data stream i in this sending cycle k is continuously read out data of one clock tick.

[0047] S105: The data slicing module slices the data stream to be sliced ​​according to the subcarrier mapping format message sent by the decision layer and the marking information and read data of all the data streams to be sliced ​​sent by the data storage module, sends them to the parallel subcarrier interface, and stores the remaining bit data of the slices in this cycle in the data storage area to be sliced.

[0048] like Figure 2 As shown, specifically including:

[0049] S1051: Before slicing, extract the slicing information of each data stream through the subcarrier mapping format message, including And the binary sequence i∈[1,N]. And calculate the length of the data to be sliced ​​data_flow_length k,i .

[0050] in, is the total number of subcarriers allocated to data stream i in transmission period k, is the number of modulation bits of the subcarrier allocated to data stream i in the transmission cycle k, the binary sequence The bit width is the total number of subcarriers M. Each bit is used to indicate whether a subcarrier ID is allocated to data flow i in this cycle. High level is valid. data_flow_length k,i is the length of the data to be sliced ​​of data stream i in the sending cycle k,

[0051] S1052: Before slicing, first check whether there is any remaining data of the data stream in the previous slicing process in the data storage area for each data stream to be sliced, and if so, extract the corresponding remaining data data_remain k,i And count the number of bits of the remaining data data_remain_length k,iThrough the marking information of all the data streams to be sliced, the read data of each data stream is spliced ​​and stored to form the data to be sliced ​​data_slice. Among them, when data_slice splices each data stream, it first splices the remaining data data_remain k,i , then splice the remaining data of the data stream in the data cache module and calculate the length of the spliced ​​data

[0052] S1053: Compare the length of the data to be sliced ​​and the length of the spliced ​​data. When data_slice_length k,i ≥data_flow_length k,i When , it means that the data of data stream i in this sending cycle has been completely spliced ​​and data slicing is performed.

[0053] S1054: The data slicing module allocates bits to the data to be sliced ​​data_slice through the subcarrier mapping format message, and The remaining bit data in the slicing period are allocated to the designated subcarriers, and the remaining bit data in the slicing period are stored in the corresponding area in the storage area for the data to be sliced.

[0054] like Figure 3 As shown, the present invention completes the functions of receiving, slicing, mapping and sending OFDM-PON service data in each sending cycle k through the sending end data processing module. Among them, the sending end data processing module is connected to the service layer, the decision layer and the subcarrier interface respectively. The sending end data processing module receives OFDM-PON service data from the service layer, sends storage information to the decision layer and receives control information from the decision layer, and the sending end data processing module maps the sliced ​​data stream and sends it to the subcarrier interface; the service layer is connected to the sending end data processing module and sends OFDM-PON service data to the sending end data processing module; the decision layer is connected to the sending end data processing module, receives the storage information of the sending end data processing module in real time, and sends the control information corresponding to this sending cycle to the sending end data processing module; the subcarrier interface is connected to the sending end data processing module, and receives the sliced ​​data from the sending end data processing module in each sending cycle k.

[0055] The data processing module at the transmitting end includes a service interface module, a data storage module and a data slicing module. Among them, the service interface module is connected to the service layer and the data storage module. The service interface module receives OFDM-PON service data from the service layer and sends the data stream to the data storage module; the data storage module is connected to the decision layer and the data slicing module. The data storage module receives the data stream of the service interface module, caches different areas according to different service destination addresses, and forms several data stream buffers. Each data stream buffer is stored and read out in sequence in a first-in-first-out queue, and sends storage information to the decision layer in real time, receives data reading information from the decision layer, and reads out the corresponding data stream to the data slicing module; the data slicing module is connected to the data storage module and the subcarrier interface. The data slicing module receives the data stream read out from the data storage module, slices the data stream to be sliced ​​and sends it to the subcarrier interface according to the subcarrier mapping format message sent by the decision layer and the tag information of all the data streams to be sliced ​​sent by the data storage module, and stores the remaining bit data of the slices in this cycle in the data storage area to be sliced.

[0056] The following is an example of implementing a real-time slicing method for OFDM-PON transmitter data on an FPGA to illustrate the solution of the present invention:

[0057] This embodiment simulates data slicing on the OFDM-PON transmitter. The data processing module of the transmitter has cached service data from multiple data sources, works under a global clock of 200Mhz, and uses a data bus with a bit width of 64bit to transmit services. In a certain transmission cycle k, the allocation result received by the transmitter from the decision layer is: data stream 1 needs to splice and slice the cached 128bit data and the remaining 9bit data in the previous transmission cycle, a total of 137bit data, to subcarriers 1-45 in this transmission cycle, using 8-QAM modulation, and each subcarrier carries 3bit data; data stream 2 needs to splice and slice the cached 64bit data and the remaining 15bit data in the previous transmission cycle, a total of 79bit data, to subcarriers 46-64 in this transmission cycle, using 16-QAM modulation, and each subcarrier carries 4bit data. After this slicing, there are 2 bits of data left unsliced ​​in data stream 1 and 3 bits of data left unsliced ​​in data stream 2. The unsliced ​​data is stored in the data storage area to be sliced, waiting to be read out in the next slicing cycle. The slicing method of the present invention has a certain interval time between two adjacent sending cycles, which can support FPGA to complete data scheduling, slicing and mapping operations within several clocks.

[0058] In this embodiment, the data slicing module first parses the slicing information sent by the decision layer. In this sending cycle k, the slicing information received by the FPGA is sc_bitload_info_i=0x6db6db6db6db6db6db6db6db6db6db6db724924924924924924, sc_data_1_assign_list=0x00001fffffffffff, sc_data_2_assign_list=0xffffe00000000000. The analysis shows that data stream 1 is allocated subcarriers 1-45, the modulation bit number is 3 bits, and the corresponding modulation format is 8-QAM; data stream 2 is allocated subcarriers 46-64, the modulation bit number is 4 bits, and the corresponding modulation format is 16-QAM. It is calculated that in this sending cycle, data stream 1 needs to be sliced ​​to send 135 bits of data, and data stream 2 needs to be sliced ​​to send 76 bits of data. Figure 4 shown.

[0059] The data received from data stream 1 is 64-bit data of 2 consecutive beats. Each beat of data is assisted by marking signals such as ofdm_rec_flow1_keep_i and ofdm_rec_flow1_valid_i, so that the data slicing module can determine the starting position of the data and whether the transmission is valid. Data stream 2 receives 64-bit data of 1 consecutive beat and marking signals. Each beat of data is spliced ​​when it arrives. First, the remaining data of the slice in the previous sending cycle is taken out from the respective data storage areas to be sliced ​​as the header of the sliced ​​data, and then the read data is spliced ​​to form the signals to be sliced ​​data_flow1_slice and data_flow2_slice, and the lengths of the spliced ​​data data_flow1_slice_length and data_flow2_slice_length are accumulated, as shown in Figure 5 shown.

[0060] Compare the length of the data to be sliced ​​with the length of the spliced ​​data in real time, and output the comparison result slice_flag, which is valid at high level. Figure 6 shown.

[0061] The spliced ​​data data_flow1_slice and data_flow2_slice are sliced ​​and mapped according to the subcarrier ID obtained by data stream allocation (data stream 1 is subcarriers 1-45, data stream 2 is subcarriers 46-64), and the number of subcarrier modulation bits (data stream 1 is 3 bits, data stream 2 is 4 bits). According to the ID of each subcarrier, the corresponding number of bits is allocated from the end of the spliced ​​data to complete the data slicing and subcarrier mapping of this sending cycle, so that the sliced ​​data can be used by the lower-layer interface, and the remaining unsliced ​​data is stored back in the data storage area to be sliced. Among them, the remaining 2 bits of data stream 1 are 2'b00, and the remaining 3 bits of data stream 2 are 3'b100, which is consistent with the theory, such as Figure 7 shown.

[0062] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A real-time data slicing method for an OFDM-PON transmitter, characterized in that: The following steps are involved: The data processing module of the OLT at the sending end receives the service data from the upper service layer through the service interface module, and writes the service data into the data storage module at the sending end, preparing for subsequent reading; The data storage module transmits the data storage status in the data storage module to the decision layer in real time; The decision layer sends a message in each sending cycle T send Sending control information to the data storage module and the data slicing module; The data storage module transmits data in each transmission cycle T send The inward data slicing module reads the data stream to be sliced ​​and sends data stream marking information; The data slicing module slices the data stream to be sliced ​​according to the subcarrier mapping format message sent by the decision layer and the marking information and read data of all the data streams to be sliced ​​sent by the data storage module, sends them to the parallel subcarrier interface, and stores the remaining bit data of the slices in this cycle in the data storage area to be sliced.

2. A real-time slicing method for OFDM-PON transmitting end data according to claim 1, characterized in that: The data storage module receives business data from the business interface module, and caches different areas according to different business destination addresses to form several data stream buffers. Each data stream buffer is stored and read out in sequence in a first-in-first-out queue.

3. The method for real-time slicing of OFDM-PON transmitting end data according to claim 1, characterized in that: The data storage module transmits the data storage status in the data storage module to the decision layer in real time, including the source address, destination address and data storage capacity of each business.

4. The OFDM-PON transmitter data real-time slicing method according to claim 1, characterized in that: After the data storage module transmits the data storage status in the data storage module to the decision layer in real time, the decision layer first calculates the data reading information and sends it to the data storage module through the data storage status, bit error rate of each ONU, delayed communication status and uplink and downlink traffic status sent in real time by the data storage module, and then calculates the subcarrier mapping format message in this sending cycle k and sends it to the data slicing module.

5. A real-time data slicing method for an OFDM-PON transmitter as claimed in claim 4, characterized in that: The data storage module is connected to the data slicing module.

6. A method for real-time slicing of OFDM-PON transmitting end data as claimed in claim 5, characterized in that: The data storage module transmits data in each transmission cycle T send The inbound data slicing module reads the data stream to be sliced ​​and sends data stream marking information, including: The data storage module reads the data information sent by the decision layer in the current sending cycle k, calculates the marking information of each data stream to be sliced, reads out the marking information and sends it to the data slicing module in parallel.

7. A method for real-time slicing of OFDM-PON transmitting end data as claimed in claim 6, characterized in that: The data storage module reads information from the data sent by the decision layer in this sending cycle k. Calculate the tag information of each data stream to be sliced And read the data Send to the data slicing module in parallel; in, is a binary symbol, indicating that the data read from data stream i in this sending cycle k is valid. is a bit identifier indicating the number of valid data bits read from data stream i in the current sending cycle k.

8. The OFDM-PON transmitter data real-time slicing method according to claim 1, characterized in that: The data slicing module sends a subcarrier mapping format message according to the decision layer, and l∈[1,M]； in, Indicates the number of data bits carried by the modulation format adopted by subcarrier l in this transmission cycle k, Indicates that in the kth transmission cycle, the ONU carried by subcarrier l is ONU i .

9. A method for real-time slicing of OFDM-PON transmitting end data as claimed in claim 8, characterized in that: The data slicing module slices the data stream to be sliced ​​according to the subcarrier mapping format message sent by the decision layer and the tag information and read data of all the data streams to be sliced ​​sent by the data storage module, sends them to the parallel subcarrier interface, and stores the remaining bit data of the slices in this cycle in the data storage area to be sliced, specifically including: Before slicing, the slicing information of each data stream is extracted through the subcarrier mapping format message, and the length of the data to be sliced ​​is calculated; Before slicing, firstly, for each data stream to be sliced, check whether there is residual data of the data stream in the previous slicing process in the data storage area to be sliced, if there is, extract the corresponding residual data and count the number of bits of the residual data; through the marking information of all the data streams to be sliced, the read data of each data stream is spliced ​​and stored to form the data to be sliced; Compare the length of the data to be sliced ​​with the length of the spliced ​​data. When the length of the spliced ​​data is greater than or equal to the length of the data to be sliced, it means that the data of the data stream i in this sending cycle has been fully spliced, and data slicing is performed; The data slicing module allocates bits of the data to be sliced ​​through the subcarrier mapping format message, and allocates them to the specified subcarriers according to the binary sequence obtained by parsing, and stores the remaining bit data in the slicing period in the corresponding area in the data storage area to be sliced.

10. The OFDM-PON transmitter data real-time slicing method according to claim 9, characterized in that: When splicing each data stream, first splice the remaining data, then splice the remaining data of the data stream in the data cache module, and calculate the length of the spliced ​​data.

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