Wireless communication systems, methods, and devices based on OFDM waveform regime

Abstract

The application relates to a wireless communication system, method and device based on an OFDM waveform system. The system comprises a sending end and a receiving end; in the sending end, a signaling section modulation unit performs pre-BCH encoding and post-channel encoding on signals, a data section modulation unit selectively performs pre-BCH encoding and post-channel encoding on signals according to channel quality grades fed back by the receiving end; a framing unit generates a preset OFDM frame structure, frames and sends signals, a channel state processing unit of the receiving end calculates channel state information and evaluates grades according to the frequency domain characteristics of a pilot sequence and a pilot sequence, and feeds back to the sending end; a data section demodulation unit demodulates a data section, performs cyclic redundancy check on the demodulated signals, selectively performs BCH decoding according to control information output by a signaling section demodulation unit and a cyclic redundancy check result, and outputs service data. The system can meet the requirements of a scene with high requirements on error rate and communication rate.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a wireless communication system, method and device based on OFDM waveform. Background Technology

[0002] With the continuous development of wireless communication technology, OFDM (Orthogonal Frequency Division Multiplexing) waveform technology has gradually emerged. This technology, due to its frequency domain orthogonality, can effectively combat frequency-selective fading caused by multipath propagation, and its parallel subcarrier transmission can improve data transmission efficiency and support high-speed transmission. Therefore, it has been widely used in wireless local area networks (WLANs). Currently, existing OFDM communication waveforms mainly adopt a framework including a signaling segment modulation unit, a data segment modulation unit, and a framing unit: the signaling segment modulation unit modulates the frame control signals, the data segment modulation unit modulates the service load, and the framing unit frames the modulated signaling and data segments according to a specific frame format to form a complete signal.

[0003] However, this traditional OFDM communication waveform method currently has many problems: the data segment uses a Turbo encoder with a master code rate of 1 / 3, the error correction decoder is single, and the error correction capability is relatively weak; it uses block pilots with a pilot density of 1 / 5, and each OFDM symbol adds a 1 / 4 cyclic prefix, resulting in a subcarrier utilization rate of only about 60% and low transmission efficiency; at the same time, the overall system has a high bit error rate, and the decoding time is fixed regardless of the channel environment, and it cannot quickly output the decoding result under better signal-to-noise ratio conditions, making it difficult to meet the requirements of scenarios with high requirements for bit error rate and communication rate, such as multi-node UAV control and real-time image transmission. Summary of the Invention

[0004] Therefore, it is necessary to provide a wireless communication system, method, and device based on OFDM waveform architecture to address the aforementioned technical problems.

[0005] A wireless communication system based on OFDM waveform technology, the system comprising: Sender and receiver; The sending end includes: The signaling segment modulation unit is used to perform pre-stage BCH coding on the signaling segment signal, and then perform post-stage channel coding. The data segment modulation unit is used to selectively perform pre-stage BCH coding on the data segment signal according to the channel quality level fed back by the receiver, and then perform subsequent stage channel coding. The framing unit is used to generate an OFDM frame structure that includes a preamble sequence, a pilot sequence, a signaling segment, and a data segment. It frames the signals output by the signaling segment modulation unit and the data segment modulation unit with the preamble sequence and the pilot sequence according to the OFDM frame structure and then transmits the framed signal. The receiving end includes: The channel state processing unit is used to calculate channel state information and evaluate channel quality level based on the frequency domain characteristics of the preamble sequence in the received signal and the pilot sequence, and to feed back the channel quality level to the framing unit of the transmitting end. The signaling segment demodulation unit is used to demodulate the signaling segments in the received signal and output the signaling segment signal of the receiving end; the signaling segment signal contains control information for indicating whether the data segment performs the preceding BCH encoding. The data segment demodulation unit is used to demodulate the data segments in the received signal, perform cyclic redundancy check on the demodulated signal, and selectively perform BCH decoding based on the control information and the cyclic redundancy check result before outputting service data.

[0006] A wireless communication method based on OFDM waveform architecture, the method comprising: The receiving end calculates channel state information and evaluates channel quality level based on the frequency domain characteristics of the preamble sequence and pilot sequence in the received signal, and feeds back the channel quality level to the transmitting end. The signaling segment signal is pre-coded by the signaling segment modulation unit at the transmitting end, and then channel-coded by the subsequent stage. The data segment modulation unit at the transmitting end selectively performs pre-stage BCH coding on the data segment signal according to the channel quality level, and then performs subsequent channel coding. The framing unit at the transmitting end generates an OFDM frame structure containing a preamble sequence, a pilot sequence, a signaling segment, and a data segment. The encoded signaling segment signal and data segment signal are framed with the preamble sequence and the pilot sequence according to the OFDM frame structure, and the framed signal is transmitted. The signaling segment in the received signal is demodulated by the signaling segment demodulation unit at the receiving end, and the signaling segment signal at the receiving end is output; the signaling segment signal contains control information for indicating whether the data segment performs the preceding BCH encoding. The receiving end demodulates the data segments in the received signal using the data segment demodulation unit, performs cyclic redundancy check on the demodulated signal, and selectively performs BCH decoding based on the control information and the cyclic redundancy check result before outputting the service data.

[0007] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program performing the following steps: The receiving end calculates channel state information and evaluates channel quality level based on the frequency domain characteristics of the preamble sequence and pilot sequence in the received signal, and feeds back the channel quality level to the transmitting end. The signaling segment signal is pre-coded by the signaling segment modulation unit at the transmitting end, and then channel-coded by the subsequent stage. The data segment modulation unit at the transmitting end selectively performs pre-stage BCH coding on the data segment signal according to the channel quality level, and then performs subsequent channel coding. The framing unit at the transmitting end generates an OFDM frame structure containing a preamble sequence, a pilot sequence, a signaling segment, and a data segment. The encoded signaling segment signal and data segment signal are framed with the preamble sequence and the pilot sequence according to the OFDM frame structure, and the framed signal is transmitted. The signaling segment in the received signal is demodulated by the signaling segment demodulation unit at the receiving end, and the signaling segment signal at the receiving end is output; the signaling segment signal contains control information for indicating whether the data segment performs the preceding BCH encoding. The receiving end demodulates the data segments in the received signal using the data segment demodulation unit, performs cyclic redundancy check on the demodulated signal, and selectively performs BCH decoding based on the control information and the cyclic redundancy check result before outputting the service data.

[0008] The aforementioned wireless communication system, method, and device based on OFDM waveform technology enhances the error correction capability of control signals and ensures reliable signal transmission by performing pre-stage BCH coding on the signaling segment signal through the signaling segment modulation unit. It also improves transmission efficiency and reduces data errors by selectively performing pre-stage BCH coding on the data segment signal based on the channel quality level fed back from the receiver through the data segment modulation unit. Furthermore, it provides accurate data segment coding selection based on the preamble sequence frequency domain characteristics and pilot sequence evaluation and feedback by the receiver channel state processing unit, ensuring the coding strategy is compatible with the channel environment. Finally, it significantly shortens the data decoding time under high signal-to-noise ratio conditions by performing BCH decoding on the signaling segment through the signaling segment demodulation unit and selectively performing BCH decoding on the data segment by combining control signals and cyclic redundancy check results, while ensuring data reliability. These embodiments of the invention can meet the requirements of scenarios with high requirements for bit error rate and communication rate, such as multi-node UAV control and real-time image transmission. Attached Figure Description

[0009] Figure 1 This is an application scenario diagram of a wireless communication method based on OFDM waveform architecture in one embodiment; Figure 2 This is a schematic diagram of the optimized signal segment structure in one embodiment; Figure 3 This is a schematic diagram of the BCH encoding system structure in one embodiment; Figure 4 This is a schematic diagram of the OFDM communication waveform frame structure in one embodiment; Figure 5This is a schematic diagram of the real and imaginary parts of the receiver preamble group 2 under the superior channel conditions in one embodiment, wherein... Figure 5 (a) is a schematic diagram of the real part of the frequency domain of the preamble 2 sequence. Figure 5 (b) is a schematic diagram of the frequency domain imaginary part of the preamble 2 sequence; Figure 6 This is a schematic diagram of the real and imaginary parts of the receiver preamble group 2 under medium channel conditions in one embodiment. Figure 6 (a) is a schematic diagram of the real part of the frequency domain of the preamble 2 sequence. Figure 6 (b) is a schematic diagram of the frequency domain imaginary part of the preamble 2 sequence; Figure 7 This is a schematic diagram of the real and imaginary parts of the receiver preamble group 2 under frequency domain conditions in one embodiment of differential channel conditions, wherein, Figure 7 (a) is a schematic diagram of the real part of the frequency domain of the preamble 2 sequence. Figure 7 (b) is a schematic diagram of the frequency domain imaginary part of the preamble 2 sequence; Figure 8 This is a schematic diagram of the processing flow of a wireless communication system based on OFDM waveform technology in one embodiment. Figure 9 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0011] In one embodiment, a wireless communication system based on OFDM waveform architecture is provided, comprising: Sender and receiver; The sending end includes: The signaling segment modulation unit is used to perform pre-stage BCH coding on the signaling segment signal, and then perform post-stage channel coding. The data segment modulation unit is used to selectively perform pre-stage BCH coding on the data segment signal according to the channel quality level fed back by the receiver, and then perform subsequent stage channel coding. The framing unit is used to generate an OFDM frame structure that includes a preamble sequence, a pilot sequence, a signaling segment, and a data segment. It frames the signals output by the signaling segment modulation unit and the data segment modulation unit with the preamble sequence and the pilot sequence according to the OFDM frame structure, and then transmits the framed signal. The receiving end includes: The channel state processing unit is used to calculate channel state information and evaluate channel quality level based on the frequency domain characteristics of the preamble sequence and the pilot sequence in the received signal, and to feed back the channel quality level to the framing unit at the transmitting end. The signaling segment demodulation unit is used to demodulate the signaling segments in the received signal and output the signaling segment signal from the receiving end; the signaling segment signal contains control information indicating whether the data segment performs the preceding BCH encoding. The data segment demodulation unit is used to demodulate the data segments in the received signal, perform cyclic redundancy check on the demodulated signal, and selectively perform BCH decoding based on the control information and the cyclic redundancy check result before outputting the service data.

[0012] In the aforementioned OFDM-based wireless communication system, the signaling segment modulation unit performs pre-stage BCH coding on the signaling segment signal, which enhances the error correction capability of the control signal and ensures the reliability of signaling transmission. The data segment modulation unit selectively performs pre-stage BCH coding on the data segment signal based on the channel quality level fed back from the receiver, which improves transmission efficiency while reducing data errors. The receiver channel state processing unit evaluates and feeds back the channel quality based on the frequency domain characteristics of the preamble sequence and the pilot sequence, providing accurate basis for data segment coding selection and ensuring that the coding strategy is compatible with the channel environment. The signaling segment demodulation unit performs BCH decoding on the signaling segment, and the data segment demodulation unit selectively performs BCH decoding based on the control signal and the cyclic redundancy check result, which significantly shortens the data decoding time under high signal-to-noise ratio conditions while ensuring data reliability. This embodiment of the invention can meet the needs of scenarios with high requirements for bit error rate and communication rate, such as multi-node UAV control and real-time image transmission.

[0013] In one embodiment, the subsequent channel coding performed by the signaling segment modulation unit is convolutional coding, and the subsequent channel coding performed by the data segment modulation unit is Turbo coding.

[0014] In this embodiment, the signaling segment modulation unit employs post-stage convolutional coding, and the data segment modulation unit employs post-stage Turbo coding. Both are cascaded using a combination of pre-stage BCH coding and post-stage coding. Compared to traditional single error correction encoders, the receiver can further correct uncorrected errors through BCH decoding on top of Turbo decoding, significantly improving overall error correction capability and effectively reducing the system bit error rate. Specifically, the Turbo coding of the data segment adapts to the large data volume characteristics of the service load, while the convolutional coding of the signaling segment adapts to the low latency requirements of control signals. The cascaded BCH coding ensures reliable transmission of service data and control signals, further enhancing the stability of the communication system.

[0015] Specifically, such as Figure 1As shown, a schematic diagram of the overall framework of an OFDM communication waveform is provided. The OFDM communication waveform framework comprises three modules: a signaling segment modulation unit, a data segment modulation unit, and a framing unit. The signaling segment modulation unit and the data segment modulation unit employ two cascaded encoders, both with error correction capabilities. At the receiving end, compared to a single encoder with error correction capabilities, after Turbo decoding, the BCH decoder performs another decoding and error correction operation to correct errors that Turbo decoding could not correct, thus improving the overall error correction capability of the system. Figure 2 The diagram shows the optimized signal segment structure, which includes code rate, modulation scheme, payload length, BCH encoding enable, CRC checksum, and tail bit. The signaling segment carries control information, and the BCH decoding enable it contains an indicator indicating whether the data segment should perform BCH encoding. The receiver must first demodulate the signaling segment and obtain this indicator through the BCH decoding of the signaling segment to accurately determine whether the data segment needs to perform BCH decoding and subsequent CRC checksum logic. This ensures that the data segment demodulation unit can flexibly skip redundant steps based on channel quality and checksum results. This ensures the reliability of the signaling segment control information and enables adaptive data segment decoding strategy, ultimately improving decoding speed under high SNR and maintaining a low bit error rate under low SNR, meeting the communication needs of multiple scenarios.

[0016] like Figure 3 As shown, a schematic diagram of a BCH encoding system is provided. BCH encoding is a composite type of cyclic code and linear block code, and error correction is achieved by adding redundant check bits to the data. Figure 3 It can be seen that the generated check bits are all arranged after the information bits. At the receiving end, when... Figure 1 If the Cyclic Redundancy Check 2 verification is correct, the BCH decoding operation can be omitted, and the final decoded data can be directly output.

[0017] In one embodiment, the OFDM frame structure includes a gain adjustment sequence, a preamble sequence, a signaling segment, and N data segments, where N is a positive integer; a pilot sequence is provided before and after each signaling segment and each data segment.

[0018] In this embodiment, signal power adaptation is achieved through a gain adjustment sequence to avoid transmission loss caused by improper power. The preamble sequence ensures synchronization, while the layout of the pilots before and after the signaling and data segments provides accurate channel estimation for each transmission segment, reducing bit errors caused by channel estimation deviations. Furthermore, the design of N data segments supports parallel transmission of multiple batches of service data, adapting to the large data volume requirements in multi-node scenarios. Simultaneously, the orderly arrangement of pilots and transmission segments reduces redundant resource occupation in traditional frame structures, effectively improving the overall subcarrier utilization rate and enhancing system transmission efficiency.

[0019] Existing OFDM communication waveform frameworks can meet the needs of scenarios with relatively low requirements for system bit error rate and communication rate, such as voice communication applications or UAV video transmission systems with a small number of network nodes. However, in scenarios with high requirements for system bit error rate and communication rate, such as multi-node UAV control and real-time image transmission systems, the existing OFDM communication waveform framework cannot meet the requirements. To reduce the overall communication waveform bit error rate while ensuring its carrier utilization, i.e., while meeting the same service information rate and low-channel environment conditions, this invention designs an OFDM communication waveform and corresponding frame structure with higher decoding rate and lower bit error rate.

[0020] like Figure 4 As shown, a schematic diagram of an OFDM communication waveform frame structure is provided. Figure 4 In this system, two different preamble groups are used. Preamble sequence 1 and preamble sequence 2 in preamble group 1 use the same 64-point CAZAC (Const Amplitude Zero Auto-Corelation) sequence for coarse timing synchronization. Preamble sequence 3 and preamble sequence 4 in preamble group 2 use asymmetric BPSK modulation followed by IFFT output, resulting in a 128-point sequence for fine timing synchronization. The pilot sequences used for channel estimation are two identical 128-point sequences, and the system's subcarrier utilization is approximately 75%.

[0021] In one embodiment, the preamble sequence includes a first preamble group and a second preamble group; the first preamble group contains two identical 64-point constant envelope zero autocorrelation sequences for coarse timing synchronization; the second preamble group contains two 128-point sequences output by IFFT after asymmetric BPSK modulation for fine timing synchronization.

[0022] In this embodiment, a hierarchical design combining coarse and fine timing synchronization is employed. Initial timing is achieved quickly by leveraging the strong autocorrelation of the CAZAC sequence, followed by precise calibration using the fine characteristics of the 128-point sequence. Compared to traditional single synchronization methods, this approach offers higher synchronization accuracy and faster response. This hierarchical synchronization reduces the impact of timing errors on subsequent channel estimation and data demodulation. Especially in scenarios with multiple dynamically moving nodes (such as drones), it ensures continuous and stable system synchronization, improving communication reliability.

[0023] In one embodiment, the pilot sequences are all 128-point sequences.

[0024] In this embodiment, the pilot sequences are all 128-point sequences. Compared with traditional shorter pilot sequences, they can contain richer channel characteristic information, enabling the receiver to obtain more detailed channel fading data during channel estimation and improving the accuracy of channel estimation. Accurate channel estimation can provide a more reliable compensation basis for the demodulation process, reduce signal distortion caused by channel fading, and further reduce the system bit error rate. At the same time, the uniform 128-point length facilitates the standardized design of frame structures and the unification of signal processing algorithms, improving the consistency and efficiency of system signal processing and adapting to the collaborative communication needs between multiple nodes.

[0025] In one embodiment, calculating channel state information and evaluating channel quality level based on the frequency domain characteristics of the preamble sequence and the pilot sequence in the received signal includes: performing a frequency domain transformation on the preamble sequence in the received signal, extracting the real and imaginary parts in the frequency domain and calculating the energy ratio; performing channel estimation based on the pilot sequence to obtain the channel fading coefficient and noise power; calculating the channel state information based on the energy ratio, the channel fading coefficient, and the noise power, and mapping the channel state information to a superior, medium, or poor channel quality level according to a pre-set judgment rule.

[0026] In this embodiment, the energy ratio of the real and imaginary parts is extracted by frequency domain transformation of the preamble sequence. Channel state information is calculated by combining the channel fading coefficient and noise power obtained from the pilot sequence and mapped to multi-level channel quality. This allows for a comprehensive assessment of channel conditions from multiple dimensions, avoiding biases from single-parameter evaluations and making channel level classification more accurate. Accurate channel quality assessment provides a reliable basis for the transmitter to adjust its coding strategy, ensuring a high degree of matching between the coding scheme and the real-time channel environment. This avoids wasted coding resources or insufficient error correction due to inaccurate channel judgment, and improves the system's adaptability to complex and changing channel environments.

[0027] At the receiving end, the frequency domain signal after FFT transformation of preamble sequence 3 and preamble sequence 4 is as follows: Figure 5-6 As shown, Figure 5 As shown, a schematic diagram of the real and imaginary parts of the receiver preamble group 2 in the frequency domain under superior channel conditions is provided, wherein... Figure 5 (a) is a schematic diagram of the real part of the frequency domain of the preamble 2 sequence. Figure 5 (b) is a schematic diagram of the frequency domain imaginary part of the preamble 2 sequence, as shown in the figure. Figure 6 As shown, a schematic diagram of the real and imaginary parts of the receiver preamble group 2 in the frequency domain under medium channel conditions is provided, wherein... Figure 6 (a) is a schematic diagram of the real part of the frequency domain of the preamble 2 sequence. Figure 6 (b) is a schematic diagram of the frequency domain imaginary part of the preamble 2 sequence, as shown in the figure. Figure 7 As shown, a schematic diagram of the real and imaginary parts of the receiver preamble group 2 in the frequency domain under differential channel conditions is provided, wherein, Figure 7(a) is a schematic diagram of the real part of the frequency domain of the preamble 2 sequence. Figure 7 (b) is a schematic diagram of the imaginary part of the preamble 2 sequence in the frequency domain. It can be seen that the imaginary part value is almost 0 under high signal-to-noise ratio conditions, while the imaginary part value is relatively large under low signal-to-noise ratio conditions. Therefore, the ratio of the real part to the imaginary part energy of the preamble sequence 3 and the preamble sequence 4 at the receiving end can be used to determine whether the node will use BCH coding when transmitting data next time.

[0028] In one embodiment, selectively performing pre-stage BCH coding on the data segment signal based on the channel quality level fed back by the receiver includes: not performing pre-stage BCH coding when the channel quality level fed back by the receiver is excellent; and performing pre-stage BCH coding when the channel quality level fed back by the receiver is medium or poor.

[0029] In this embodiment, with Figure 5-6 The situation shown illustrates the determination rules. Figure 5 A channel environment with a real-to-imaginary energy ratio greater than 2 is considered excellent. Figure 6 The ratio of real part to imaginary part energy is greater than 1.5 and less than 2, indicating a medium channel environment. Figure 7 The energy ratio of the real part to the imaginary part is less than 1.5, indicating a suboptimal channel environment. This adaptive adjustment strategy in this embodiment allocates coding resources on demand, avoiding the problems of wasted resources in good channels and insufficient error correction in poor channels, as is common with traditional fixed redundancy systems. This further optimizes the overall communication performance of the system under different channel conditions.

[0030] In one embodiment, selectively performing BCH decoding and outputting service data based on control information and cyclic redundancy check (CRC) results includes: when the control information indicates that BCH encoding of the data segment is not enabled, directly outputting the demodulated service data; when the control information indicates that BCH encoding of the data segment is enabled, if the CRC passes, skipping BCH decoding and directly outputting the service data; if the CRC fails, performing BCH decoding and outputting the service data.

[0031] Specifically, such as Figure 8As shown, the transmitting end enforces pre-stage BCH coding on the signaling segment based on the channel quality level fed back by the receiving end. For the data segment, BCH coding is not performed when the channel is excellent (BCH coding is disabled), and is performed when the channel is average / poor (BCH coding is enabled). When the receiving end demodulates the data segment, it first obtains the control information for enabling BCH coding through the signaling segment. If the control information indicates that it is disabled, the demodulated service data is directly output as shown by the dotted line in the flowchart. If it indicates that it is enabled, a cyclic redundancy check is performed first. If the check passes, BCH decoding is skipped and the data is output directly; otherwise, BCH decoding is performed before outputting. This implementation method can eliminate redundant BCH decoding steps when the channel is excellent, significantly improving the decoding rate. When the channel is average / poor, BCH decoding is used to enhance error correction capabilities and reduce the data error rate, ultimately meeting the needs of scenarios with high requirements for bit error rate and communication rate, such as multi-node UAV control and real-time image transmission.

[0032] In one specific embodiment, such as Figure 8 As shown, a schematic diagram of the processing flow of a wireless communication system based on OFDM waveform architecture is provided. Figure 8 This paper demonstrates the adaptive communication process between the transmitter (TX) and receiver (RX) in a wireless communication system based on OFDM waveform architecture. The core of this process is the dynamic optimization of the coding strategy and receiving procedure through channel quality grading (excellent / medium / poor), specifically including: TX transmitter: Following the sequence order of the frame structure, the outputs of the signaling segment modulation unit and the data segment modulation unit are assembled with pilot and preamble sequences into a complete frame, which is then transmitted through constellation modulation IFFT and other processes. Simultaneously, the pilot and preamble sequences in the frame structure provide a reference for judging channel quality (excellent / medium / poor), thereby triggering adaptive adjustments to the coding strategy.

[0033] RX receiver: First, timing synchronization carrier synchronization is achieved through the preamble sequence in the frame structure, and then CSI (channel state information) calculation and channel estimation are completed through the pilot sequence. Subsequently, according to the segmentation of the frame structure (signaling segment and data segment), control information parsing is performed on the signaling segment and service load demodulation is performed on the data segment, and finally signal recovery is achieved.

[0034] In one embodiment, a wireless communication method based on OFDM waveform architecture is provided, comprising: Step 102: The receiving end calculates the channel state information and evaluates the channel quality level based on the frequency domain characteristics of the preamble sequence and the pilot sequence in the received signal, and feeds back the channel quality level to the transmitting end. Step 104: Perform pre-stage BCH coding on the signaling segment signal through the signaling segment modulation unit at the transmitting end, and then perform post-stage channel coding. Step 106: The data segment modulation unit at the transmitting end selectively performs pre-stage BCH coding on the data segment signal according to the channel quality level, and then performs subsequent channel coding. Step 108: Through the framing unit of the transmitting end, an OFDM frame structure containing a preamble sequence, pilot sequence, signaling segment and data segment is generated. The encoded signaling segment signal and data segment signal are framed with the preamble sequence and pilot sequence according to the OFDM frame structure, and the framed signal is transmitted. Step 110: The signaling segment in the received signal is demodulated by the signaling segment demodulation unit of the receiving end, and the signaling segment signal of the receiving end is output; the signaling segment signal contains control information for indicating whether the data segment performs the preceding BCH encoding. Step 112: Demodulate the data segments in the received signal through the data segment demodulation unit of the receiving end, perform cyclic redundancy check on the demodulated signal, and selectively perform BCH decoding based on the control information and the cyclic redundancy check result before outputting the service data.

[0035] It should be understood that, although Figure 8 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 8 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0036] Specific limitations regarding OFDM-based wireless communication methods can be found in the limitations of OFDM-based wireless communication systems described above, and will not be repeated here. Each module in the aforementioned OFDM-based wireless communication system can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0037] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 9As shown, the computer device includes a processor, memory, network interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The network interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a wireless communication method based on the OFDM waveform system. The display screen can be a liquid crystal display (LCD) or an e-ink display. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0038] Those skilled in the art will understand that Figure 9 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0039] In one embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps of the method described above.

[0040] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0041] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A wireless communication system based on OFDM waveform technology, characterized in that, The system includes a transmitter and a receiver; The sending end includes: The signaling segment modulation unit is used to perform pre-stage BCH coding on the signaling segment signal, and then perform post-stage channel coding. The data segment modulation unit is used to selectively perform pre-stage BCH coding on the data segment signal according to the channel quality level fed back by the receiver, and then perform subsequent stage channel coding. The framing unit is used to generate an OFDM frame structure that includes a preamble sequence, a pilot sequence, a signaling segment, and a data segment. It frames the signals output by the signaling segment modulation unit and the data segment modulation unit with the preamble sequence and the pilot sequence according to the OFDM frame structure and then transmits the framed signal. The receiving end includes: The channel state processing unit is used to calculate channel state information and evaluate channel quality level based on the frequency domain characteristics of the preamble sequence in the received signal and the pilot sequence, and to feed back the channel quality level to the framing unit of the transmitting end. The signaling segment demodulation unit is used to demodulate the signaling segments in the received signal and output the signaling segment signal of the receiving end; the signaling segment signal contains control information for indicating whether the data segment performs the preceding BCH encoding. The data segment demodulation unit is used to demodulate the data segments in the received signal, perform cyclic redundancy check on the demodulated signal, and selectively perform BCH decoding based on the control information and the cyclic redundancy check result before outputting service data.

2. The system according to claim 1, characterized in that, The subsequent channel coding performed by the signaling segment modulation unit is convolutional coding, and the subsequent channel coding performed by the data segment modulation unit is Turbo coding.

3. The system according to claim 1, characterized in that, The preamble sequence includes a first preamble group and a second preamble group; the first preamble group contains two identical 64-point constant envelope zero autocorrelation sequences for coarse timing synchronization; the second preamble group contains two 128-point sequences output by IFFT after asymmetric BPSK modulation for fine timing synchronization.

4. The system according to claim 1, characterized in that, The pilot sequences are all 128-point sequences.

5. The system according to claim 1, characterized in that, The step of calculating channel state information and evaluating channel quality level based on the frequency domain characteristics of the preamble sequence in the received signal and the pilot sequence includes: The preamble sequence in the received signal is transformed in the frequency domain to extract the real and imaginary parts in the frequency domain and to calculate the energy ratio. Channel estimation is performed based on the pilot sequence to obtain the channel fading coefficient and noise power. Based on the energy ratio, channel fading coefficient, and noise power, channel state information is calculated, and the channel state information is mapped to excellent, medium, or poor channel quality levels according to pre-set judgment rules.

6. The system according to claim 1, characterized in that, The selective execution of pre-stage BCH coding on the data segment signal based on the channel quality level fed back from the receiver includes: When the receiver feedback channel quality level is excellent, the preceding BCH coding is not performed; When the receiver feedback channel quality level is medium or poor, the preceding BCH coding is performed.

7. The system according to claim 1, characterized in that, Based on the control information and cyclic redundancy check results, selectively performing BCH decoding and outputting service data includes: When the control information indicates that BCH encoding of the data segment is not enabled, the demodulated service data is directly output. When the control information indicates that BCH encoding of the data segment is enabled, if the cyclic redundancy check passes, the BCH decoding is skipped and the service data is output directly. If the cyclic redundancy check fails, the BCH decoding is performed and the service data is output.

8. The system according to claim 1, characterized in that, The OFDM frame structure includes a gain adjustment sequence, a preamble sequence, a signaling segment, and N data segments, where N is a positive integer; a pilot sequence is provided before and after each signaling segment and each data segment.

9. A wireless communication method based on OFDM waveform technology, characterized in that, The method includes: The receiving end calculates channel state information and evaluates channel quality level based on the frequency domain characteristics of the preamble sequence and pilot sequence in the received signal, and feeds back the channel quality level to the transmitting end. The signaling segment signal is pre-coded by the signaling segment modulation unit at the transmitting end, and then channel-coded by the subsequent stage. The data segment modulation unit at the transmitting end selectively performs pre-stage BCH coding on the data segment signal according to the channel quality level, and then performs subsequent channel coding. The framing unit at the transmitting end generates an OFDM frame structure containing a preamble sequence, a pilot sequence, a signaling segment, and a data segment. The encoded signaling segment signal and data segment signal are framed with the preamble sequence and the pilot sequence according to the OFDM frame structure, and the framed signal is transmitted. The signaling segment in the received signal is demodulated by the signaling segment demodulation unit at the receiving end, and the signaling segment signal at the receiving end is output; the signaling segment signal contains control information for indicating whether the data segment performs the preceding BCH encoding. The receiving end demodulates the data segments in the received signal using the data segment demodulation unit, performs cyclic redundancy check on the demodulated signal, and selectively performs BCH decoding based on the control information and the cyclic redundancy check result before outputting the service data.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method of claim 9.

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