Power line carrier communication system and method based on polar coding

Abstract

The application relates to the field of power line carrier communication, and provides a power line carrier communication system and method based on Polar coding. The system comprises a Polar coding and decoding module integrated in an FPGA chip, an OFDM communication module, and a soft core processor. The Polar coding and decoding module is used for coding a service data stream to obtain Polar code data or decoding the Polar code data. The OFDM communication module is used for modulating the Polar code data to obtain an OFDM analog signal or demodulating the OFDM analog signal. The soft core processor is connected to the Polar coding and decoding module and the OFDM communication module through a bus and is used for configuring the communication parameters of the Polar coding and decoding module and the OFDM communication module. The application realizes a communication structure with high throughput, low power consumption and dynamic configuration, and improves the adaptability of the system in different application scenarios.

Description

Technical Field

[0001] This application relates to the field of power line carrier communication, specifically to a power line carrier communication system and method based on Polar coding. Background Technology

[0002] With the rapid development of the energy internet and the in-depth advancement of smart grid construction, the power system is undergoing a profound digital transformation. The traditional power grid is no longer merely a carrier of energy transmission; it has been endowed with advanced functions such as two-way information interaction, real-time monitoring, demand-side response, and distributed energy access. Power line communication (PLC) is a key technology for overcoming the bottlenecks of traditional power line communication technology and empowering the smart grid.

[0003] The inherent limitations of power line carrier communication (PLC) technology and the complexity of the power line channel environment determine its inherent shortcomings. First, there is the fundamental constraint of the channel environment: persistent background noise, severe impulse noise, and narrowband interference in power line channels pose the greatest challenges to communication reliability and speed; existing technologies can only attenuate these noises, not eliminate them. Load variations causing channel impedance jumps and significant distance- and frequency-dependent attenuation continuously affect signal quality and coverage. The multi-branch, multi-stage series topology of low-voltage distribution networks increases signal transmission loss. Second, there are bottlenecks in capacity and speed. Within the actual spectrum where regulations and interference coexist, the existing combination of Orthogonal Frequency Division Multiplexing (OFDM) with Quadrature Amplitude Modulation (QAM) and Turbo coding is already close to its physical layer speed limit, making it difficult to meet the higher bandwidth demands of future applications such as video surveillance and massive distributed energy resource millisecond-level data exchange.

[0004] Existing implementations of Polar encoding in power line carrier communication systems have several shortcomings. First, pure software implementations are limited by processor clock speeds, making it difficult to meet the high-speed, real-time transmission requirements of power line carrier communication in terms of encoding / decoding speed and throughput. While pure hardware implementations are faster, their system functionality is fixed, and communication parameters are difficult to modify once the FPGA logic synthesis is complete. Second, in existing solutions, key communication parameters such as Polar encoding are fixed during the system design phase, making it impossible to dynamically adjust them based on changes in channel quality or service requirements during system operation. This results in insufficient adaptability of the system to different application scenarios. Summary of the Invention

[0005] To address one of the shortcomings of existing technologies, this application provides a power line carrier communication system and method based on Polar encoding. The system implements Polar encoding power line carrier communication in collaboration with an FPGA and a soft-core processor to achieve a high-throughput, low-power, and dynamically configurable communication structure, thus adapting to different channel conditions and communication scenarios.

[0006] The first aspect of this application provides a power line carrier communication system based on Polar encoding, including: a Polar encoding / decoding module, an OFDM communication module, a power line physical channel module, and a soft-core processor, wherein the Polar encoding / decoding module, the OFDM communication module, and the soft-core processor are integrated in an FPGA chip; The Polar codec module is used to encode business data streams to obtain Polar code data, or to decode Polar code data. The OFDM communication module is used to modulate Polar code data to obtain an orthogonal frequency division multiplexed analog signal, or to demodulate an orthogonal frequency division multiplexed analog signal; The power line physical channel module is used to superimpose noise onto the orthogonal frequency division multiplexed analog signal from the OFDM communication module, and to simulate the distortion of the power line channel, outputting an analog signal with simulated distortion. The soft-core processor is connected to the Polar codec module and the OFDM communication module via a bus, and is used to configure the communication parameters of the Polar codec module and the OFDM communication module. The communication parameters of the Polar codec module include code length, code rate and decoding depth, and the communication parameters of the OFDM communication module include modulation and demodulation parameters.

[0007] In this embodiment of the application, the Polar encoding / decoding module includes a Polar encoding module and a Polar decoding module; The OFDM communication module includes an OFDM transmitting module and an OFDM receiving module; The Polar encoding module is used to encode the business data stream to obtain Polar code data; The OFDM transmission module is used to modulate the Polar code data to obtain an orthogonal frequency division multiplexed analog signal; The OFDM receiving module is used to demodulate the received analog signal to obtain soft bit data in the form of log-likelihood ratio (LLR); The Polar decoding module is used to decode the demodulated soft bit data to obtain decoded data.

[0008] In this embodiment of the application, the Polar encoding module includes: a CRC encoding unit, a bit interleaving unit, and a parallel encoding unit; The CRC encoding unit is used to add a check bit to the input business data stream; The bit interleaving unit is used to interleave data with additional parity bits; The parallel encoding unit is used to perform Polar encoding on the interleaved data using a tree-structured parallel computing unit according to the code length and code rate configured in the soft core processor, generate Polar codes and store them in the block memory, and write the encoding completion flag bit into the corresponding status register.

[0009] In this embodiment of the application, the Polar decoding module includes: a log-likelihood ratio storage unit, a computation unit, an information queue storage unit, and a CRC check unit; The log-likelihood ratio storage unit is used to store the soft bit data output by the OFDM receiving module; The computation unit is used to: perform decoding operations based on the soft bit information output by the log-likelihood ratio storage unit, and output decoding result data; update and sort the metric value of the current decoding path in parallel during the decoding process; retain several paths with the best metric value after each decoding stage according to the decoding depth configured by the soft core processor, and output the decoding path with the best metric value at the end of the decoding process. The CRC check unit is used to check the decoding result data output by the arithmetic unit, output the decoding result data that passes the check as the decoding data, and write the decoding completion flag bit into the corresponding status register.

[0010] In this embodiment of the application, the soft-core processor is connected to the Polar codec module and the OFDM communication module via the AXI-Stream bus for data interaction; The soft-core processor is connected to the configuration registers of the Polar codec module and the OFDM communication module via the AXI-Lite bus, and is used to configure the code length, code rate and decoding depth of the Polar codec module, as well as the modulation and demodulation parameters of the OFDM communication module.

[0011] In this embodiment of the application, during the data transmission process, the soft core processor injects the service data stream to be transmitted into the Polar encoding module through the AXI-Stream bus. After polling the encoding completion flag bit of the Polar encoding module, it writes a start instruction to the control register of the OFDM transmission module, triggering the OFDM transmission module to read Polar code data from the block memory for modulation. In the data reception process, after the soft core processor polls the demodulation completion flag of the OFDM receiving module, it writes a start instruction to the control register of the Polar decoding module, triggering the Polar decoding module to read soft bit data from the block memory for decoding, and after polling the decoding completion flag, it reads the decoded data through the AXI-Stream bus.

[0012] In this embodiment of the application, the system further includes a dynamic random access memory (DDR3) connected to the soft-core processor. The dynamic random access memory has independent storage space allocated to the Polar encoding module, Polar decoding module, OFDM transmission module and OFDM receiving module respectively; The soft-core processor accesses the storage space of the Polar encoding module, Polar decoding module, OFDM transmitting module, and OFDM receiving module via the AXI bus protocol. This allows it to inject test data into the storage space corresponding to any specified module or read intermediate calculation results stored in the data storage space of any specified module under the instruction of the host computer.

[0013] In this embodiment of the application, the power line physical channel module includes a noise injection unit and an impedance simulation unit; The noise injection unit is used to superimpose narrowband interference signal, impulse noise signal and / or Gaussian white noise signal onto the analog signal from the OFDM communication module via orthogonal frequency division multiplexing. The impedance simulation unit is used to simulate the frequency-selective fading and multipath transmission distortion characteristics of power lines. The OFDM receiving module receives an analog signal from the power line; the analog signal is coupled to the power line after noise is superimposed by the noise injection unit and the distortion is simulated by the impedance simulation unit.

[0014] A second aspect of this application provides a power line carrier communication method based on Polar coding, comprising: The business data stream is encoded using the Polar codec module to obtain Polar code data, or Polar code data is decoded. The Polar code data is modulated by the OFDM communication module to obtain an orthogonal frequency division multiplexed analog signal, or the orthogonal frequency division multiplexed analog signal is demodulated to obtain Polar code data. The power line physical channel module adds noise to the analog signal from the OFDM communication module and simulates the distortion of the power line channel, outputting an analog signal with simulated distortion. The communication parameters of the Polar codec module and the OFDM communication module are configured through a soft-core processor connected to the Polar codec module and the OFDM communication module. The communication parameters of the Polar codec module include code length, code rate and decoding depth, and the communication parameters of the OFDM communication module include modulation and demodulation parameters.

[0015] In this embodiment, the soft-core processor is connected to the Polar codec module and the OFDM communication module via the AXI-Stream bus for data interaction.

[0016] The soft-core processor is connected to the configuration registers of the Polar codec module and the OFDM communication module via the AXI-Lite bus, and is used to configure the code length, code rate and decoding depth of the Polar codec module, as well as the modulation and demodulation parameters of the OFDM communication module.

[0017] In this embodiment of the application, the Polar encoding / decoding module includes a Polar encoding module and a Polar decoding module; The OFDM communication module includes an OFDM transmitting module and an OFDM receiving module; The Polar encoding module is used to encode the business data stream to obtain Polar code data; The OFDM transmission module is used to modulate the Polar code data to obtain an orthogonal frequency division multiplexed analog signal; The OFDM receiving module is used to demodulate the received analog signal to obtain soft bit data in the form of log-likelihood ratio; The Polar decoding module is used to decode the demodulated soft bit data to obtain decoded data.

[0018] In this embodiment of the application, during the data transmission process, the soft core processor injects the service data stream to be transmitted into the Polar encoding module through the AXI-Stream bus. After polling the encoding completion flag bit of the Polar encoding module, it writes a start instruction to the control register of the OFDM transmission module, triggering the OFDM transmission module to read Polar code data from the block memory for modulation. In the data reception process, after the soft core processor polls the demodulation completion flag of the OFDM receiving module, it writes a start instruction to the control register of the Polar decoding module, triggering the Polar decoding module to read soft bit data from the block memory for decoding, and after polling the decoding completion flag, it reads the decoded data through the AXI-Stream bus.

[0019] In this embodiment of the application, the power line physical channel module includes a noise injection unit and an impedance simulation unit; The noise injection unit is used to superimpose narrowband interference signal, impulse noise signal and / or Gaussian white noise signal onto the analog signal from the OFDM communication module via orthogonal frequency division multiplexing. The impedance simulation unit is used to simulate the frequency-selective fading and multipath transmission distortion characteristics of power lines. The analog signal, after being superimposed with noise by the noise injection unit and distorted by the impedance simulation unit, is coupled to the power line, and the OFDM receiving module receives the analog signal from the power line.

[0020] The above technical solution integrates the Polar codec module, OFDM communication module, and soft-core processor into an FPGA chip. The soft-core processor configures the communication parameters of the Polar codec module, such as code length, code rate, and decoding depth, as well as the modulation and demodulation parameters of the OFDM communication module, via a bus. During system operation, the communication parameters of the Polar codec can be dynamically adjusted according to changes in channel quality or service requirements, improving the system's adaptability in different application scenarios. This solution uses hardware logic to implement Polar codec in the FPGA, significantly reducing data processing latency and significantly improving system throughput and encoding / decoding rate, meeting the high-speed transmission requirements of power line carrier communication. At the same time, the soft-core processor configures communication parameters in real time via the bus, allowing for flexible switching of operating modes in different application scenarios without resynthesizing the FPGA logic, greatly improving the system's adaptability and flexibility. The collaborative design of the OFDM communication module and the power line physical channel module can superimpose noise on the signal and simulate the distortion of the power line channel, effectively dealing with multipath fading, narrowband interference, and impulse noise, ensuring stable signal transmission in complex power line environments.

[0021] Other features and advantages of the technical solution of this application will be described in detail in the following detailed implementation section. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is an overall structural block diagram of the power line carrier communication system based on Polar coding provided in the embodiments of this application; Figure 2 This is a structural block diagram of the Polar encoding / decoding module of the power line carrier communication system based on Polar encoding provided in the embodiments of this application; Figure 3 This is a structural block diagram of the transmitting end of the OFDM communication module of the power line carrier communication system based on Polar coding provided in this application embodiment; Figure 4 This is a structural block diagram of the receiving end of the OFDM communication module of the power line carrier communication system based on Polar coding provided in the embodiments of this application; Figure 5 This is a schematic diagram of the data flow between various modules in a power line carrier communication system based on Polar coding provided in the embodiments of this application; Figure 6 This is a flowchart of a power line carrier communication method based on Polar coding provided in an embodiment of this application. Detailed Implementation

[0023] To make the technical solutions and advantages of the embodiments of this application clearer, the exemplary embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0024] Figure 1 This is an overall structural block diagram of the power line carrier communication system based on Polar coding provided in the embodiments of this application. For example... Figure 1 As shown, the power line carrier communication system based on Polar encoding provided in this embodiment mainly includes: a data source module, a Polar encoding / decoding module, a MicroBlaze soft-core processor, and an OFDM communication module. The modules are interconnected via an AXI bus, and the Polar encoding / decoding module, OFDM communication module, and MicroBlaze soft-core processor are integrated into the same FPGA chip. The data source module generates the service data stream to be transmitted and interacts with the MicroBlaze soft-core processor via the AXI bus interface. The service data stream can be test data from a host computer or actual power line carrier communication service data.

[0025] The MicroBlaze soft-core processor serves as the core of the system's control and management. It communicates with the configuration and status registers of each hardware module via the AXI-Lite bus, enabling functions such as configuration parameter distribution, status monitoring, and intermediate result reading. It also performs high-speed data interaction with each module via the AXI-Stream bus. The MicroBlaze soft-core processor receives communication parameters from the host computer, including Polar code length, code rate, SCL list depth, and OFDM modulation order, and writes them into the configuration registers of each module for their use.

[0026] During system operation, the MicroBlaze soft-core processor schedules in a state machine mode: in a specific state, it polls the status registers of each module, and when it detects the end flag of a module (the flag register is set to 1), it reads the corresponding BRAM or DDR3 storage result and passes the data to the next module according to the instructions of the control register, thereby realizing module-level pipeline control and system data flow management.

[0027] The power line carrier communication system also includes a power line physical channel module ( Figure 1 (Not shown). The power line physical channel module is used to simulate or access the actual power line transmission environment, including a noise injection unit and an impedance simulation unit. The noise injection unit is used to superimpose narrowband interference signals, impulse noise signals, and / or additive white Gaussian noise (AWGN) signals onto the orthogonal frequency division multiplexed analog signals from the OFDM communication module. Narrowband interference is used to simulate narrowband interference from other communication systems or power electronic devices in the power line channel; impulse noise is used to simulate sudden impulse interference caused by switching operations, lightning, etc., in the power line channel; white Gaussian noise is used to simulate thermal noise in the channel. The amplitude, frequency, pulse width, and other parameters of each noise source can be configured by the soft-core processor. The impedance simulation unit is used to simulate the frequency-selective fading and multipath transmission distortion characteristics of the power line. The impedance simulation unit is implemented through a configurable filter bank, and its frequency response can be set according to a typical power line channel model (such as a multipath channel model). The analog signal, after being superimposed with noise by the noise injection unit and distorted by the impedance simulation unit, is coupled to the actual power line, and the OFDM receiving module receives the analog signal from the power line. The power line physical channel module can be directly connected to the actual power line interface to achieve experimental-level communication verification.

[0028] The Polar encoding / decoding module includes a Polar encoding module and a Polar decoding module. Both modules are implemented using FPGA hardware logic and employ a multi-stage pipelined parallel architecture. Figure 2As shown, the Polar encoding module includes a CRC encoding unit, a bit interleaving unit, and a parallel encoding unit. The CRC encoding unit adds cyclic redundancy check bits to the input service data stream for error detection at the receiving end. The CRC encoding unit operates on the input data according to a preset CRC polynomial, appending the calculated check bits to the original data before outputting them. The bit interleaving unit performs interleaving processing on the data after the added check bits. Interleaving rearranges the data according to a specific interleaving pattern, dispersing burst errors over time and improving the burst error resistance of subsequent Polar encoding. The parallel encoding unit, based on the code length and code rate configured by the soft-core processor, uses a tree-structured parallel processing unit to perform Polar encoding on the interleaved data, generating Polar codes and storing them in block RAM (BRAM), while simultaneously writing the encoding completion flag to the corresponding status register. The core of Polar encoding is encoding the input data according to the generator matrix of the Polar code. Specifically, for a Polar code with a code length of N and an information bit length of K, the encoding process can be represented as x = u * G. N Where u is the input vector containing information bits and frozen bits, and G N This is the generator matrix for the Polar code. The parallel encoding unit uses a tree structure to decompose the encoding operation into multi-level parallel basic operation units, and improves the computational efficiency through pipeline technology. After encoding is completed, the data is stored in BRAM, and the completion flag is written to the status register.

[0029] The Polar decoding module is a hardware decoder based on the SCL (Successive Cancellation List) decoding algorithm. For example... Figure 2 As shown, the Polar decoding module includes: a control unit ( Figure 2The module includes a log-likelihood ratio (LLR) storage unit, an arithmetic unit, an information queue storage unit, and a CRC check unit. The control unit receives the decoding depth parameters (SCL list size L) from the soft-core processor and controls the start and scheduling of the SCL decoding process. The control unit contains a finite state machine that manages the various stages of the decoding process: initialization, LLR loading, bit-by-bit decoding, path selection, and result output. The LLR storage unit stores the soft-bit data output by the OFDM receiver module, i.e., the log-likelihood ratio of each bit. The LLR storage unit is implemented using a dual-port BRAM, supporting concurrent read and write operations of the control unit. The core arithmetic units in the Polar decoding module mainly include a path metric unit and a path selection unit, as well as an information recursion unit and an update unit. During the decoding process, the path metric unit updates and sorts the metric values ​​of the current decoding path in parallel. For the SCL decoding algorithm, in each decoding stage, each path generates two branches, 0 and 1. The path metric unit calculates the path metric value (PM value) for each branch and sorts the metric values ​​of all candidate paths. The path selection unit, based on the decoding depth (list size L) configured in the soft-core processor, retains the L paths with the best metric values ​​after each decoding stage, discarding the rest, thus controlling the increase in decoding complexity. At the end of decoding, the path selection unit outputs the decoding path with the best metric value as the decoding result. The information queue storage unit of the Polar decoding module stores the historical bit information of each surviving path for the path metric unit to reference in subsequent decoding processes. The CRC check unit performs CRC checks on the decoding result data output by the arithmetic unit, outputting the decoded result data that passes the check as the final decoded data and writing the decoding completion flag into the corresponding status register. If all surviving paths fail the CRC check, the path with the best metric value is selected as the decoding result, and the corresponding error flag is output. The OFDM communication module includes an OFDM transmitting module and an OFDM receiving module. Figure 3As shown, the OFDM transmission module, in order of data flow, includes: a QAM modulation module, an IFFT module, a cyclic prefix addition module, a preamble generation module, and a data packet assembly module. The QAM modulation module maps the Polar-encoded bit data into complex symbols, including channel interleaving (H), diversity copying (I), and constellation point mapping (J). Based on the modulation order configured by the soft-core processor (e.g., QPSK, 16QAM, 64QAM), the QAM modulation module maps the input bit sequence into complex frequency domain symbols according to the corresponding constellation diagram. The IFFT module (K) converts the frequency domain symbols to the time domain. The IFFT module uses a pipelined radix-2 or radix-4 Inverse Fast Fourier Transform (IFFT) algorithm to convert the QAM-modulated frequency domain symbol block into a time-domain sampling point sequence. The cyclic prefix addition module (L) adds a cyclic prefix (CP) before each OFDM symbol to combat multipath delay spread in power line channels. The length of the cyclic prefix can be configured by the soft-core processor according to channel conditions. The preamble sequence generation module (M) generates the preamble sequence for OFDM frames. The preamble sequence includes a short preamble and a long preamble, used for symbol synchronization, frequency offset estimation, and channel estimation at the receiver. The data packet assembly module (N) assembles the time-domain data with a cyclic prefix, the preamble sequence, and other frame header information into a complete OFDM baseband data frame according to a predetermined frame format, and outputs it to the digital-to-analog converter or the power line physical channel module. Each submodule of the OFDM transmission module stores the processed data in the BRAM and sets the status register to 1 for polling monitoring by the soft-core processor. After data is written to the control register, each submodule inputs the calculation result to the next module based on the data written to the control register.

[0030] like Figure 4As shown, the OFDM receiver module, in order of data flow, includes: a data unpacking module, an FFT module, a cyclic prefix removal module, and a QAM demodulation module. The data unpacking module extracts the preamble, cyclic prefix, and valid data portion from the received baseband data frame, performs gain control (O) and frame synchronization (P), and completes symbol timing synchronization. Then, the cyclic prefix removal module (Q) removes the cyclic prefix from each symbol, extracting the valid time-domain sampling points. The FFT module (R) converts the time-domain sampling points back to frequency-domain symbols. The FFT module employs a pipelined Fast Fourier Transform (FFT) algorithm that matches the IFFT module at the transmitting end. The QAM demodulation module performs QAM demodulation through demodulation (S), grouping (T), and channel deinterleaving (U). Optionally, the OFDM receiver module also includes a channel estimation and compensation module. This module uses the preamble sequence to estimate the channel frequency response and performs channel equalization on the received frequency-domain symbols based on the estimation results, eliminating amplitude attenuation and phase rotation introduced by the power line channel. Channel estimation can employ algorithms such as least squares (LS) or minimum mean square error (MMSE). The QAM demodulation module demodulates the equalized frequency domain complex symbols into soft-bit information, i.e., soft-bit data in the form of log-likelihood ratio (LLR), according to the constellation diagram corresponding to the transmitter, and outputs it to the Polar decoding module. The design of each submodule of the OFDM receiver module also satisfies the requirement of storing the processed data in BRAM, while setting the status register to 1 for polling and monitoring by the soft-core processor.

[0031] like Figure 5As shown, the core architecture of the power line carrier communication system in this application is implemented based on an FPGA chip. Its top-level structure mainly consists of a soft-core processor (MicroBlaze), which enables independent transmission of control commands and high-speed data through the AXI-Lite bus and AXI-Stream bus. The soft-core processor (MicroBlaze), as the core of system control and management, is connected to the configuration registers and status registers of each hardware module through the AXI interconnect structure. Specifically, the soft-core processor configures parameters and reads the status of the data generation module (A), Polar encoding module (B), OFDM transmission module (C), OFDM receiving module (E), Polar decoding module (F), and data comparison module (G) through the AXI-Lite bus, enabling the distribution of communication parameters (such as code length, code rate, decoding depth, and modulation scheme) and the monitoring of the operating status of each module. High-speed data interaction between the functional modules is achieved through the AXI-Stream bus. The data stream sequentially passes through the data generation module (A) to generate service data, is injected into the Polar encoding module (B) for channel coding, and then enters the OFDM transmission module (C) for modulation. The modulated signal is then superimposed with noise and simulated channel distortion by the power line physical channel module (D), received and demodulated by the OFDM receiving module (E), and outputs soft bit information to the Polar decoding module (F) for decoding. Finally, the data comparison module (G) performs error statistics or data verification. The system also includes a DDR3 memory connected to the soft-core processor, and uses a DMA controller in conjunction with the AXI bus protocol to achieve large-capacity caching and read / write access of intermediate operation results from each module. This is used for data injection or result reading under the instructions of the host computer to achieve module-level functional verification and debugging. Each module adopts a unified "master / slave (M / S)" interface design, and uses the AXI interconnect structure (axi_interconnect) to achieve data interaction with the soft-core processor and DDR3, and is configured as a master or slave device according to its functional role.

[0032] The MicroBlaze soft-core processor is the central hub of the entire system, interacting with all modules within it. Its main functions include: configuring parameters, controlling data flow, debugging and verification, and interacting with the host computer. The configuration parameters are implemented by the MicroBlaze soft-core processor acquiring communication parameters (including Polar code length, code rate, SCL list depth, OFDM modulation order, etc.) from the host computer and then writing these parameters into the GPIO registers of each hardware module. Each module reads the parameters from the registers to perform its operation. The MicroBlaze soft-core processor reads and writes to the GPIO registers via the AXI-Lite interface.

[0033] The specific implementation of data flow control includes the following steps: In the data transmission process, the MicroBlaze soft-core processor injects the service data stream to be transmitted into the Polar encoding module via the AXI-Stream bus. After completing encoding, the Polar encoding module stores the encoding result in the BRAM and writes the encoding completion flag to the status register. Upon detecting the encoding completion flag, the MicroBlaze soft-core processor writes a start command to the control register of the OFDM transmission module, triggering the OFDM transmission module to read Polar code data from the BRAM for modulation. After completing modulation, the OFDM transmission module outputs the modulation result to the power line physical channel module. In the data reception process, after demodulation, the OFDM receiving module stores the LLR-formatted soft-bit data in the BRAM and writes the demodulation completion flag to the status register. Upon detecting the demodulation completion flag, the MicroBlaze soft-core processor writes a start command to the control register of the Polar decoding module, triggering the Polar decoding module to read the soft-bit data from the BRAM for SCL decoding. After decoding, the Polar decoding module stores the decoded data in the BRAM and writes the decoding completion flag to the status register. After the MicroBlaze soft-core processor polls the decoding completion flag, it reads the decoded data via the AXI-Stream bus. During hardware module operation, it stores the results of its respective operations in the BRAM and sets the corresponding register flag to 1, indicating that the step has been completed. The MicroBlaze soft-core processor operates in a state machine mode, polling these status registers in a specific state. When a register is set to 1, it writes to the control register to select a branch or reads intermediate data from the BRAM and feeds it back to the host computer, thus realizing the functions of controlling data flow and debugging.

[0034] The specific implementation methods for debugging and verification include: each submodule is allocated a space in DDR3 (Dynamic Random Access Memory) for data extraction and injection. In this mode, extracting the calculation results of a submodule to the host computer allows verification of the correctness of any module's calculations. Simultaneously, data can be injected into any module to verify the functionality and performance of each module under specified data conditions. Specifically, independent storage spaces are allocated in the DDR3 memory for the Polar encoding module, Polar decoding module, OFDM transmitting module, and OFDM receiving module. The soft-core processor accesses the storage spaces of each module via the AXI bus protocol, enabling it to inject test data into the storage space corresponding to any specified module or read intermediate calculation results stored in the data storage space of any specified module under host computer instructions.

[0035] The soft-core processor is also used to read decoded data from the BRAM or DDR3 storage space of the Polar decoding module via the AXI bus under the instruction of the host computer, and upload it to the host computer via the serial communication interface or Ethernet interface for bit error rate statistics and communication quality analysis.

[0036] The complete system workflow includes a transmission link and a reception link. In the transmission link, the service data stream sequentially passes through the Polar coding module for channel coding (including CRC coding, bit interleaving, and Polar parallel coding), the OFDM transmission module for QAM modulation, IFFT transformation, and cyclic prefix addition, outputting an orthogonal frequency division multiplexed analog signal to the power line physical channel module. The power line physical channel module adds noise to the signal and simulates channel distortion before coupling the distorted analog signal to the power line. In the reception link, the distorted analog signal from the power line physical channel module sequentially passes through the OFDM receiving module for data unpacking, cyclic prefix removal, FFT transformation, channel estimation and equalization, and QAM demodulation, outputting LLR-formatted soft bit information to the Polar decoding module for SCL decoding (including path metric update, path selection, and CRC check), obtaining the decoded data.

[0037] The soft-core processor controls the startup timing, operating status, and data flow direction of each module in the transmitting and receiving links, respectively, to achieve data transmission and reception scheduling in full-duplex or half-duplex communication modes.

[0038] In the system operation process, the MicroBlaze soft-core processor first loads communication parameters according to the host computer instructions, and then sequentially starts the data source module, Polar encoding module, and OFDM transmitter module. When the receiver receives the data, it outputs the restored data after OFDM demodulation and Polar decoding, and returns the bit error statistics information to the MicroBlaze soft-core processor to realize performance monitoring and adaptive optimization.

[0039] In a preferred embodiment, the FPGA chip is a Xilinx Kintex-7 series or Artix-7 series, and the MicroBlaze soft-core processor operates at a frequency of 100MHz. The Polar code length can be configured to 256, 512, 1024, or 2048 bits, the code rate can be configured to 1 / 2, 2 / 3, 3 / 4, or 5 / 6, and the SCL decoding list depth can be configured to 4, 8, 16, or 32. The OFDM modulation method can be configured to QPSK, 16QAM, 64QAM, or 256QAM, the number of subcarriers is 256 or 1024, and the cyclic prefix length can be configured to 1 / 4, 1 / 8, or 1 / 16 of the OFDM symbol length. After system power-on, the MicroBlaze soft-core processor first completes its own initialization, and then reads the ID registers of each hardware module via the AXI-Lite bus to confirm the module's existence. Subsequently, the MicroBlaze soft-core processor waits for configuration instructions from the host computer. Upon receiving the configuration command, the MicroBlaze soft-core processor writes the communication parameters into the configuration registers of each module and initiates the data transmission process. Throughout the communication process, the MicroBlaze soft-core processor continuously polls the status registers of each module, monitors the system's operating status in real time, and reports operating logs and performance statistics to the host computer as needed.

[0040] The Polar-encoded power line carrier communication system provided in this application integrates a Polar encoding / decoding module, an OFDM communication module, and a soft-core processor into an FPGA chip. The soft-core processor configures communication parameters such as code length, code rate, and decoding depth of the Polar encoding / decoding module, as well as modulation and demodulation parameters of the OFDM communication module, via a bus. During system operation, the Polar encoding / decoding communication parameters can be dynamically adjusted according to changes in channel quality or service requirements, improving the system's adaptability in different application scenarios. This solution uses hardware logic to implement Polar encoding / decoding in the FPGA, significantly reducing data processing latency and substantially improving system throughput and encoding / decoding rate, meeting the high-speed transmission requirements of power line carrier communication. Simultaneously, the soft-core processor configures communication parameters in real time via the bus, allowing for flexible switching of operating modes in different application scenarios without resynthesizing the FPGA logic, greatly enhancing the system's adaptability and flexibility. The collaborative design of the OFDM communication module and the power line physical channel module can superimpose noise onto the signal and simulate power line channel distortion, effectively addressing multipath fading, narrowband interference, and impulse noise, ensuring stable signal transmission in complex power line environments.

[0041] This application achieves hardware and software co-optimization of Polar encoding and OFDM communication, which not only ensures the high speed and stability of the communication system, but also has flexible online configuration and debugging capabilities, making it particularly suitable for scenarios such as power line carrier communication, industrial IoT and smart grid.

[0042] Figure 6 This is a flowchart of a power line carrier communication method based on Polar coding provided in an embodiment of this application. Figure 6 As shown, the power line carrier communication method based on Polar coding provided in this embodiment includes the following steps: S610 uses the Polar codec module to encode the business data stream to obtain Polar code data, or to decode the Polar code data. S620 modulates Polar code data through OFDM communication module to obtain orthogonal frequency division multiplexing analog signal, or demodulates orthogonal frequency division multiplexing analog signal to obtain Polar code data; S630 adds noise to the orthogonal frequency division multiplexed analog signal from the OFDM communication module through the power line physical channel module, and simulates the distortion of the power line channel, outputting an analog signal with simulated distortion. The S640, through a soft-core processor connected to the Polar codec module and the OFDM communication module, configures the communication parameters of the Polar codec module and the OFDM communication module. The communication parameters of the Polar codec module include code length, code rate, and decoding depth, while the communication parameters of the OFDM communication module include modulation and demodulation parameters.

[0043] The soft-core processor connects to the Polar codec module and the OFDM communication module via the AXI-Stream bus for data exchange. It also connects to the configuration registers of the Polar codec module and the OFDM communication module via the AXI-Lite bus to configure the code length, code rate, and decoding depth of the Polar codec module, as well as the modulation and demodulation parameters of the OFDM communication module.

[0044] The Polar encoding / decoding module includes a Polar encoding module and a Polar decoding module; the OFDM communication module includes an OFDM transmitting module and an OFDM receiving module; the Polar encoding module is used to encode the service data stream to obtain Polar code data; the OFDM transmitting module is used to modulate the Polar code data to obtain an orthogonal frequency division multiplexed analog signal; the OFDM receiving module is used to demodulate the received analog signal to obtain soft bit data in log-likelihood ratio form; the Polar decoding module is used to decode the demodulated soft bit data to obtain decoded data.

[0045] In the data transmission process, the soft-core processor injects the service data stream to be transmitted into the Polar encoding module via the AXI-Stream bus. After polling the encoding completion flag of the Polar encoding module, it writes a start command to the control register of the OFDM transmission module, triggering the OFDM transmission module to read Polar code data from the block memory for modulation. In the data reception process, after polling the demodulation completion flag of the OFDM reception module, the soft-core processor writes a start command to the control register of the Polar decoding module, triggering the Polar decoding module to read soft bit data from the block memory for decoding. After polling the decoding completion flag, it reads the decoded data via the AXI-Stream bus.

[0046] The power line physical channel module includes a noise injection unit and an impedance simulation unit. The noise injection unit is used to superimpose narrowband interference signals, impulse noise signals, and / or Gaussian white noise signals onto the orthogonal frequency division multiplexed analog signals from the OFDM communication module. The impedance simulation unit is used to simulate the frequency-selective fading and multipath transmission distortion characteristics of the power line. The analog signal, after being superimposed with noise by the noise injection unit and distorted by the impedance simulation unit, is coupled to the power line, and the OFDM receiving module receives the analog signal from the power line.

[0047] The technical details of the Polar-coded power line carrier communication method provided in this embodiment can be understood by referring to the specific implementation details of the Polar-coded power line carrier communication system described above. This method has the same technical effect as the Polar-coded power line carrier communication system described above, and will not be described again here.

[0048] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take 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. The solutions in the embodiments of this application can be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0049] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0050] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0051] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0052] The optional embodiments of this application have been described in detail above with reference to the accompanying drawings. However, the embodiments of this application are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of this application, various simple modifications can be made to the technical solutions of the embodiments of this application, and these simple modifications all fall within the protection scope of the embodiments of this application. Furthermore, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. As long as such combination does not violate the spirit of the embodiments of this application, it should also be considered as the content disclosed in the embodiments of this application.

Claims

1. A power line carrier communication system based on Polar coding, characterized in that, include: The system comprises a Polar codec module, an OFDM communication module, a power line physical channel module, and a soft-core processor, all integrated within an FPGA chip. The Polar codec module is used to encode business data streams to obtain Polar code data, or to decode Polar code data. The OFDM communication module is used to modulate Polar code data to obtain an orthogonal frequency division multiplexed analog signal, or to demodulate an orthogonal frequency division multiplexed analog signal; The power line physical channel module is used to superimpose noise onto the orthogonal frequency division multiplexed analog signal from the OFDM communication module, and to simulate the distortion of the power line channel, outputting an analog signal with simulated distortion. The soft-core processor is connected to the Polar codec module and the OFDM communication module via a bus, and is used to configure the communication parameters of the Polar codec module and the OFDM communication module. The communication parameters of the Polar codec module include code length, code rate and decoding depth, and the communication parameters of the OFDM communication module include modulation and demodulation parameters.

2. The power line carrier communication system based on Polar coding according to claim 1, characterized in that, The Polar encoding / decoding module includes a Polar encoding module and a Polar decoding module; The OFDM communication module includes an OFDM transmitting module and an OFDM receiving module; The Polar encoding module is used to encode the business data stream to obtain Polar code data; The OFDM transmission module is used to modulate the Polar code data to obtain an orthogonal frequency division multiplexed analog signal; The OFDM receiving module is used to demodulate the received analog signal to obtain soft bit data in the form of log-likelihood ratio; The Polar decoding module is used to decode the demodulated soft bit data to obtain decoded data.

3. The power line carrier communication system based on Polar coding according to claim 2, characterized in that, The Polar encoding module includes: a CRC encoding unit, a bit interleaving unit, and a parallel encoding unit; The CRC encoding unit is used to add a check bit to the input business data stream; The bit interleaving unit is used to interleave data with additional parity bits; The parallel encoding unit is used to perform Polar encoding on the interleaved data using a tree-structured parallel computing unit according to the code length and code rate configured in the soft core processor, generate Polar codes and store them in the block memory, and write the encoding completion flag bit into the corresponding status register.

4. The power line carrier communication system based on Polar coding according to claim 3, characterized in that, The Polar decoding module includes: a log-likelihood ratio storage unit, a computation unit, an information queue storage unit, and a CRC check unit; The log-likelihood ratio storage unit is used to store the soft bit data output by the OFDM receiving module; The computation unit is used to: perform decoding operations based on the soft bit information output by the log-likelihood ratio storage unit, and output decoding result data; update and sort the metric value of the current decoding path in parallel during the decoding process; retain several paths with the best metric value after each decoding stage according to the decoding depth configured by the soft core processor, and output the decoding path with the best metric value at the end of the decoding process. The CRC verification unit is used to verify the decoding result data output by the arithmetic unit, output the decoding result data that passes the verification as the decoding data, and write the decoding completion flag bit into the corresponding status register.

5. The power line carrier communication system based on Polar coding according to claim 1, characterized in that, The soft-core processor is connected to the Polar codec module and the OFDM communication module via the AXI-Stream bus for data interaction; The soft-core processor is connected to the configuration registers of the Polar codec module and the OFDM communication module via the AXI-Lite bus, and is used to configure the code length, code rate and decoding depth of the Polar codec module, as well as the modulation and demodulation parameters of the OFDM communication module.

6. The power line carrier communication system based on Polar coding according to claim 1, characterized in that, In the data transmission process, the soft core processor injects the service data stream to be transmitted into the Polar encoding module through the AXI-Stream bus. After polling the encoding completion flag bit of the Polar encoding module, it writes a start instruction to the control register of the OFDM transmission module, triggering the OFDM transmission module to read Polar code data from the block memory for modulation. In the data reception process, after the soft core processor polls the demodulation completion flag of the OFDM receiving module, it writes a start instruction to the control register of the Polar decoding module, triggering the Polar decoding module to read soft bit data from the block memory for decoding, and after polling the decoding completion flag, it reads the decoded data through the AXI-Stream bus.

7. The power line carrier communication system based on Polar coding according to claim 2, characterized in that, The system also includes a dynamic random access memory connected to the soft-core processor; The dynamic random access memory has independent storage space allocated to the Polar encoding module, Polar decoding module, OFDM transmission module and OFDM receiving module respectively; The soft-core processor accesses the storage space of the Polar encoding module, Polar decoding module, OFDM transmitting module, and OFDM receiving module via the AXI bus protocol. This allows it to inject test data into the storage space corresponding to any specified module or read intermediate calculation results stored in the data storage space of any specified module under the instruction of the host computer.

8. The power line carrier communication system based on Polar coding according to claim 2, characterized in that, The power line physical channel module includes a noise injection unit and an impedance simulation unit; The noise injection unit is used to superimpose narrowband interference signal, impulse noise signal and / or Gaussian white noise signal onto the analog signal from the OFDM communication module via orthogonal frequency division multiplexing. The impedance simulation unit is used to simulate the frequency-selective fading and multipath transmission distortion characteristics of power lines. The OFDM receiving module receives an analog signal from the power line; the analog signal is coupled to the power line after noise is superimposed by the noise injection unit and the distortion is simulated by the impedance simulation unit.

9. A power line carrier communication method based on Polar coding, characterized in that, include: The business data stream is encoded using the Polar codec module to obtain Polar code data, or Polar code data is decoded. The Polar code data is modulated by the OFDM communication module to obtain an orthogonal frequency division multiplexed analog signal, or the orthogonal frequency division multiplexed analog signal is demodulated to obtain Polar code data. The power line physical channel module adds noise to the analog signal from the OFDM communication module and simulates the distortion of the power line channel, outputting an analog signal with simulated distortion. The communication parameters of the Polar codec module and the OFDM communication module are configured through a soft-core processor connected to the Polar codec module and the OFDM communication module. The communication parameters of the Polar codec module include code length, code rate and decoding depth, and the communication parameters of the OFDM communication module include modulation and demodulation parameters.

10. The power line carrier communication method based on Polar coding according to claim 9, characterized in that, The soft-core processor is connected to the Polar codec module and the OFDM communication module via the AXI-Stream bus for data interaction; The soft-core processor is connected to the configuration registers of the Polar codec module and the OFDM communication module via the AXI-Lite bus, and is used to configure the code length, code rate and decoding depth of the Polar codec module, as well as the modulation and demodulation parameters of the OFDM communication module.

11. The power line carrier communication method based on Polar coding according to claim 9, characterized in that, The Polar encoding / decoding module includes a Polar encoding module and a Polar decoding module; The OFDM communication module includes an OFDM transmitting module and an OFDM receiving module; The Polar encoding module is used to encode the business data stream to obtain Polar code data; The OFDM transmission module is used to modulate the Polar code data to obtain an orthogonal frequency division multiplexed analog signal; The OFDM receiving module is used to demodulate the received analog signal to obtain soft bit data in the form of log-likelihood ratio; The Polar decoding module is used to decode the demodulated soft bit data to obtain decoded data.

12. The power line carrier communication method based on Polar coding according to claim 11, characterized in that, In the data transmission process, the soft core processor injects the service data stream to be transmitted into the Polar encoding module through the AXI-Stream bus. After polling the encoding completion flag bit of the Polar encoding module, it writes a start instruction to the control register of the OFDM transmission module, triggering the OFDM transmission module to read Polar code data from the block memory for modulation. In the data reception process, after the soft core processor polls the demodulation completion flag of the OFDM receiving module, it writes a start instruction to the control register of the Polar decoding module, triggering the Polar decoding module to read soft bit data from the block memory for decoding, and after polling the decoding completion flag, it reads the decoded data through the AXI-Stream bus.

13. The power line carrier communication method based on Polar coding according to claim 11, characterized in that, The power line physical channel module includes a noise injection unit and an impedance simulation unit; The noise injection unit is used to superimpose narrowband interference signal, impulse noise signal and / or Gaussian white noise signal onto the analog signal from the OFDM communication module via orthogonal frequency division multiplexing. The impedance simulation unit is used to simulate the frequency-selective fading and multipath transmission distortion characteristics of power lines. The analog signal, after being superimposed with noise by the noise injection unit and distorted by the impedance simulation unit, is coupled to the power line, and the OFDM receiving module receives the analog signal from the power line.

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