CN-122027421-A - Data transmission method, device and system of Orthogonal Frequency Division Multiplexing (OFDM) system

CN122027421ACN 122027421 ACN122027421 ACN 122027421ACN-122027421-A

Abstract

The application discloses a data transmission method, device and system of an Orthogonal Frequency Division Multiplexing (OFDM) system, which comprises the steps of obtaining a frequency domain receiving signal sequence of at least one receiving end, wherein the frequency domain receiving signal sequence comprises a useful signal, an interference signal and a noise signal, determining signal-to-interference-and-noise ratios of signals on all subcarriers according to the signal power of the useful signal, the interference signal and the noise signal, determining an achievable secret rate of the OFDM system according to the signal-to-interference-and-noise ratios of the signals on all subcarriers, determining a target cyclic prefix length and a target coding and modulation mode according to the achievable secret rate of the OFDM system and the maximum delay spread of a channel, and transmitting a data packet to be transmitted based on the target coding and modulation mode, wherein the data packet to be transmitted comprises data to be transmitted and cyclic prefixes of the target cyclic prefix length.

Inventors

LIU XINPING
LI YONG
ZHANG YUDONG
ZHANG ZHICHAO

Assignees

中移物联网有限公司
中国移动通信集团有限公司

Dates

Publication Date: 20260512
Application Date: 20260112

Claims (10)

1. A data transmission method of an orthogonal frequency division multiplexing OFDM system, applied to the OFDM system, the method comprising: acquiring a frequency domain receiving signal sequence of at least one receiving end, wherein the frequency domain receiving signal sequence comprises a useful signal, an interference signal and a noise signal; Determining the signal-to-interference-and-noise ratio of signals on each subcarrier according to the signal power of the useful signal, the interference signal and the noise signal, and determining the reachable secret rate of the OFDM system according to the signal-to-interference-and-noise ratio of the signals on each subcarrier; Determining a target cyclic prefix length and a target coding and modulation mode according to the achievable secret rate of the OFDM system and the maximum delay spread of a channel; And transmitting a data packet to be transmitted based on the target coding and modulation mode, wherein the data packet to be transmitted comprises the data to be transmitted and a cyclic prefix with the target cyclic prefix length.
2. The method of claim 1, wherein said determining a target cyclic prefix length based on the achievable secret rate of the OFDM system and the maximum delay spread of the channel comprises: Determining a value range of the length of the cyclic prefix according to the maximum delay spread of the channel; And selecting the target cyclic prefix length from the range of the cyclic prefix length value so as to maximize the reachable secret rate of the OFDM system.
3. The method according to claim 1, wherein said transmitting the data packet to be transmitted based on the coding and modulation scheme comprises: acquiring the data to be transmitted; coding and modulating the data to be transmitted according to the target coding and modulating mode; Adding the cyclic prefix with the target cyclic prefix length to the coded and modulated data to be transmitted to obtain the data packet to be transmitted; And sending the data packet to be transmitted.
4. The method according to claim 1, wherein said transmitting the data packet to be transmitted based on the coding and modulation scheme comprises: Receiving the data packet to be transmitted; Removing the cyclic prefix with the target cyclic prefix length from the data packet to be transmitted to obtain a pilot signal; And decoding and demodulating the pilot signal according to the target coding and modulating modes to obtain the data to be transmitted.
5. A data transmission apparatus of an orthogonal frequency division multiplexing, OFDM, system, comprising: the acquisition module is used for acquiring a frequency domain received signal sequence of at least one receiving end, wherein the frequency domain received signal sequence comprises a useful signal, an interference signal and a noise signal; The first determining module is used for determining the signal-to-interference-plus-noise ratio of the signals on each subcarrier according to the signal power of the useful signals, the interference signals and the noise signals, and determining the reachable secret rate of the OFDM system according to the signal-to-interference-plus-noise ratio of the signals on each subcarrier; A second determining module, configured to determine a target cyclic prefix length and a target coding and modulation mode according to the achievable secret rate of the OFDM system and the maximum delay spread of the channel; And the transmission module is used for transmitting a data packet to be transmitted based on the target coding and modulation mode, wherein the data packet to be transmitted comprises the data to be transmitted and a cyclic prefix with the target cyclic prefix length.
6. The OFDM system is characterized by comprising a sending end, at least one channel and at least one receiving end, wherein the sending end is used for transmitting a data packet to be transmitted to the at least one receiving end through at least one channel based on a target coding and modulation mode, the data packet to be transmitted comprises the data to be transmitted and a cyclic prefix with a target cyclic prefix length, and the target coding and modulation mode and the target cyclic prefix length are determined based on the achievable confidentiality rate of the OFDM system and the maximum delay spread of the channel.
7. The OFDM system of claim 6, wherein the transmitting end comprises an input module, a coding and modulation module, an add cyclic prefix module, and a first synchronization module; the input module is used for acquiring data to be transmitted; the coding and modulating module is used for coding and modulating the data to be transmitted according to the target coding and modulating mode; the cyclic prefix adding module is configured to add a cyclic prefix with the target cyclic prefix length to the coded and modulated data to be transmitted, so as to obtain the data packet to be transmitted; the first synchronization module is configured to send the data packet to be transmitted to at least one receiving end through at least one channel.
8. The OFDM system of claim 7, wherein the transmitting end further comprises an inverse fast fourier transform module and a time-reversal pre-filter; the inverse fast Fourier transform module is used for performing inverse fast Fourier transform on the coded and modulated data to be transmitted and inputting the data to be transmitted after the inverse fast Fourier transform into the cyclic prefix adding module; The time reversal pre-filter is used for carrying out filtering processing on the data packet to be transmitted and inputting the data packet to be transmitted after the filtering processing into the first synchronization module.
9. The OFDM system of claim 6, wherein the receiving end includes a second synchronization module, a remove cyclic prefix module, and a de-encoding and de-modulating module; The second synchronization module is configured to receive the data packet to be transmitted through at least one channel; The cyclic prefix removing module is configured to remove, for the data packet to be transmitted, a cyclic prefix with the target cyclic prefix length, to obtain a pilot signal; the de-coding and de-modulating module is used for decoding and de-modulating the pilot signal according to the target coding and modulating mode to obtain the data to be transmitted.
10. The OFDM system of claim 9, wherein the receiving end further comprises a fast fourier transform module and an equalization module; the fast Fourier transform module is used for performing fast Fourier transform on the pilot signal and inputting the pilot signal subjected to the fast Fourier transform into the equalization module; The equalization module is used for carrying out phase shift elimination processing on the pilot signal after the fast Fourier transformation and inputting the pilot signal after the phase shift elimination processing into the de-coding and de-modulating module.

Description

Data transmission method, device and system of Orthogonal Frequency Division Multiplexing (OFDM) system Technical Field The application belongs to the technical field of wireless communication, and particularly relates to a data transmission method, device and system of an Orthogonal Frequency Division Multiplexing (OFDM) system. Background In order to ensure the security of data transmission, the conventional security technology is mainly implemented by an encryption algorithm based on computational complexity, but with the improvement of the computational capability of a computer, the use of the conventional security technology also faces serious security risks. The method based on the physical layer security technology adopted at present can ensure the security of information transmission under the condition of eavesdropping with wireless computing resources, and is mainly realized by an artificial noise technology and a beam forming technology, but the technologies are usually combined with a multi-antenna technology, and only good effects can be shown under the condition of a large number of antennas, and when the system is equipped with a small number of antennas, the security of the system cannot be ensured. Disclosure of Invention The embodiment of the application aims to provide a data transmission method, a data transmission device and a data transmission system of an Orthogonal Frequency Division Multiplexing (OFDM) system, which can solve the problem that the safety of the system cannot be ensured when the system is provided with a small number of antennas. In a first aspect, an embodiment of the present application provides a data transmission method of an orthogonal frequency division multiplexing OFDM system, where the method includes obtaining a frequency domain received signal sequence of at least one receiving end, where the frequency domain received signal sequence includes a useful signal, an interference signal, and a noise signal, determining a signal-to-interference-and-noise ratio of a signal on each subcarrier according to signal powers of the useful signal, the interference signal, and the noise signal, determining an achievable secret rate of the OFDM system according to the signal-to-interference-and-noise ratio of the signal on each subcarrier, determining a target cyclic prefix length and a target coding and modulation mode according to the achievable secret rate of the OFDM system and a maximum delay spread of a channel, and transmitting a data packet to be transmitted based on the target coding and modulation mode, where the data packet to be transmitted includes data to be transmitted and a cyclic prefix of the target cyclic prefix length. In a second aspect, an embodiment of the present application provides a data transmission device of an orthogonal frequency division multiplexing OFDM system, where the device includes an acquisition module configured to acquire a frequency domain received signal sequence of at least one receiving end, where the frequency domain received signal sequence includes a useful signal, an interference signal, and a noise signal, a first determination module configured to determine a signal-to-interference-and-noise ratio of a signal on each subcarrier according to signal powers of the useful signal, the interference signal, and the noise signal, and determine an achievable secret rate of the OFDM system according to the signal-to-interference-noise ratio of the signal on each subcarrier, a second determination module configured to determine a target cyclic prefix length and a target coding and modulation mode according to the achievable secret rate of the OFDM system and a maximum delay spread of a channel, and a transmission module configured to transmit a data packet to be transmitted based on the target coding and modulation mode, where the data packet to be transmitted includes the data to be transmitted and the cyclic prefix of the target cyclic prefix length. In a third aspect, an embodiment of the present application provides an OFDM system, where the OFDM system includes a transmitting end, at least one channel, and at least one receiving end, where the transmitting end is configured to transmit, to at least one receiving end, a data packet to be transmitted based on a target coding and modulation mode through at least one channel, where the data packet to be transmitted includes cyclic prefixes of data to be transmitted and a target cyclic prefix length, where the target coding and modulation mode and the target cyclic prefix length are determined based on an achievable secret rate of the OFDM system and a maximum delay spread of the channel. In a fourth aspect, an embodiment of the present application provides an electronic device comprising a processor, a memory and a program or instruction stored on the memory and executable on the processor, the program or instruction implementing the steps of the method according to the first aspect