CN-122001529-A - Discrete fragment transmission method and system for underdensity meteor trail channel

CN122001529ACN 122001529 ACN122001529 ACN 122001529ACN-122001529-A

Abstract

The invention discloses a discrete fragment transmission method and a system for underdensity meteor trail channels, wherein the method comprises the steps that a transmitting end establishes a communication link with a receiving end by adopting an active blind detection mechanism, and locks a communication frequency point; after a communication link is established, a sending end deletes error correction codes to original data to be transmitted to generate a coded data stream, the coded data stream is divided into a plurality of independent discrete sliced data, the independent discrete sliced data are transmitted on a locked communication frequency point according to a set sequence, a receiving end performs integrity check on each discrete sliced data received and requests the sending end to retransmit the current discrete sliced data when the check fails, and the receiving end recovers the original data in a cross-window accumulation mode. The invention can greatly improve the utilization rate of weak underdense meteor channels, effectively reduce the waiting time of a communication system and improve the reliability of the system.

Inventors

LI ZAN
Tian Chengxi
WAN JIAJUN
SHI JIA
TIE ZHUANGZHUANG
ZHANG ZHENG
ZHANG SHENGYU

Assignees

西安电子科技大学

Dates

Publication Date: 20260508
Application Date: 20260317

Claims (10)

1. A discrete slice transmission method for underdensity meteor trail channels is characterized by comprising the following steps: S1, a transmitting end establishes a communication link with a receiving end by adopting an active blind detection mechanism, and locks a communication frequency point; s2, after the communication link is established, the sending end deletes error correction codes to the original data to be transmitted to generate a coded data stream, and the coded data stream is segmented into a plurality of independent discrete segmented data, and the data stream is transmitted on the locked communication frequency points according to a set sequence; S3, the receiving end performs integrity check on each piece of received discrete fragment data and requests the sending end to retransmit the current discrete fragment data when the check fails; S4, the receiving end recovers the original data in a cross-window accumulation mode.
2. The method for transmitting discrete slices for underdensity meteor trail channels according to claim 1, wherein S1 comprises: s1.1, the sending end polls and sends detection signals on a plurality of preset candidate frequency points; s1.2, the sending end enters a monitoring state after sending the detection signal so as to wait for a response signal from the receiving end; s1.3, when the receiving end successfully captures the detection signal at the current candidate frequency point, the receiving end sends a response signal to the sending end; and S1.4, after the sending end receives the response signal, locking the current candidate frequency point to serve as a communication frequency point, completing link handshake, and establishing a communication link.
3. The method for transmitting discrete slices for underdensity meteor trail channels according to claim 1, wherein the step S2 comprises: s2.1, the sending end carries out erasure error correction coding based on Reed-Solomon codes on the original data to be transmitted to generate a coded data stream containing redundant information; S2.2, dividing the coded data stream to generate a plurality of independent discrete fragment data, wherein each discrete fragment data comprises an independent data segment to be transmitted, a check bit and a fragment index; And S2.3, in the locked communication frequency point, the sending end takes the discrete fragment data as a basic transmission unit and continuously sends the discrete fragment data to the receiving end in a streaming mode.
4. A method of discrete burst transmission for underdensity class meteor trail channels according to claim 3, wherein the check bits are CRC cyclic redundancy check codes, the check bits of each discrete burst data are formed by performing a CRC operation on the current discrete burst data, and the check bits are appended at the end of a data segment of the current discrete burst data.
5. The method for discrete tile transmission for an underdensity class meteor trail channel of claim 3, wherein S2.3 comprises: And the sending end takes the discrete fragment data as a basic transmission unit on the locked communication frequency point, and continuously transmits the discrete fragment data in an available time window by using a streaming transmission strategy until the window is closed or the data is transmitted, wherein the streaming transmission mode means that the sending end does not wait for the confirmation of single discrete fragment data and continuously transmits the discrete fragment data until the window is closed or the data is transmitted.
6. The method for transmitting discrete slices for underdensity meteor trail channels according to claim 3, wherein S3 comprises: The receiving end demodulates and checks the integrity of the received discrete fragment data piece by piece in real time, if the check is passed, the current discrete fragment data is judged to be valid and the valid discrete fragment data is stored in a reorganization buffer area arranged in the receiving end; And the transmitting end dynamically adjusts a transmitting queue according to the feedback information and retransmits the relevant discrete fragment data in the feedback information.
7. The method for transmitting discrete slices for underdensity meteor trail channels according to claim 6, wherein S4 comprises: The receiving end counts the number of the effective discrete sliced data accumulated in the reorganization buffer in real time, when the number of the effective discrete sliced data reaches a preset decoding threshold, the data in the reorganization buffer is extracted and is rearranged according to the sliced index, RS decoding is executed, if the decoding is successful, the original data is restored, the transmission task is completed, if the decoding is failed, the existing effective discrete sliced data is reserved, and the received new effective discrete sliced data is continued to wait for participating in the decoding until the decoding is successful.
8. A discrete fragment transmission system for underdensity meteor trail channels is characterized by comprising a transmitting end and a receiving end, wherein, After the communication link is established, deleting error correction codes to the original data to be transmitted to generate a coded data stream, and dividing the coded data stream into a plurality of independent discrete fragments of data to be transmitted on the locked communication frequency point according to a preset sequence; the receiving end is used for receiving the discrete fragment data, carrying out integrity check on each received discrete fragment data, requesting the sending end to retransmit the current discrete fragment data when the check fails, and recovering the original data in a cross-window accumulation mode.
9. The underdensity class meteor trail channel oriented discrete burst transmission system of claim 8, wherein the receiving end is provided with a reassembly buffer for storing valid discrete burst data that passes the verification.
10. The method of claim 1 wherein the sender and the receiver adopt an asymmetric time slot design, the sender occupies a data transmission time slot to continuously send the discrete fragment data in a streaming mode, the receiver occupies a response time slot to intensively feed back an integrity check result and a retransmission request to the sender, and when a communication window is closed to interrupt data transmission, the sender directly continues to transmit the incomplete discrete fragment data along a locked communication frequency point in a subsequent window until decoding is successful.

Description

Discrete fragment transmission method and system for underdensity meteor trail channel Technical Field The invention belongs to the technical field of wireless communication, and particularly relates to a discrete fragment transmission method and system for underdensity meteor trail channels. Background Meteor trail communication is a technology for realizing beyond-line-of-sight communication by reflecting or scattering radio waves by using ionized trail generated when meteor enters the atmosphere. The most remarkable characteristics of the channel are that the occurrence of the communication window is random, the duration is extremely short (usually in the order of tens of milliseconds to hundreds of milliseconds), the window interval is uncertain, the channel characteristics are obviously influenced by multipath effect, frequency offset, rapid phase change, external interference and other factors, and the propagation environment with high error code and low signal to noise ratio is integrally presented. The meteor trail channels are mainly classified into an underdensity meteor trail channel (Underdense Meteor Burst Channel) and an excessively density meteor trail channel (Overdense Meteor Burst Channel) according to the trail electron density and attenuation characteristics thereof. The frequency of occurrence of the underdensity meteor trail channel is high, but the signal strength is weak, the duration is extremely short (usually tens of milliseconds), and the signal amplitude decays exponentially. In general, the duration of an underdensity meteor trail channel is extremely short, the channel fading of the underdensity meteor trail channel obeys a negative exponential function, and the underdensity meteor trail channel has the characteristic of large-scale rapid change, and the traditional communication mode cannot be utilized. Because the number of the underdensity meteor trail channels is numerous, a core bottleneck for effectively reducing the average waiting time of the meteor trail communication system is how to design a novel transmission mechanism so as to improve the utilization rate of the underdensity meteor trail channels. The existing transmission scheme for meteor trail channels is mostly based on the whole packet transmission idea, namely after detecting a channel window, trying to complete the transmission and confirmation of the whole data packet in one or several continuous longer windows. The scheme has the following outstanding problems in practical application that (1) waiting time is prolonged, uncertainty is high, the occurrence probability of a strong and stable channel window is low, a data packet can be sent only after waiting for a long time, service completion delay distribution has long tail characteristics, and the requirements of emergency communication, time-sensitive service and the like on quick delivery are difficult to meet, and (2) the weak window has low utilization rate, a large number of short and weak underdense windows are idle due to insufficient bearing of a complete data packet or a complex handshake process, so that precious channel resource waste is caused. (3) The robustness is insufficient, and the whole packet transmission is required to be retransmitted wholly once the error occurs under the conditions of low signal-to-noise ratio, large frequency offset and rapid phase change, so that the efficiency is low. (4) The interrupt recovery capability is poor, the transmission process is easy to be interrupted randomly, and if an effective breakpoint continuous transmission and accumulation receiving mechanism is lacked, the transmission continuity is seriously affected after each interruption. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a discrete fragment transmission method and a system for an underdense meteor trail channel, which aim to solve the problems of low handshake success rate, frequent transmission interruption and difficult breakpoint continuous transmission in a channel environment with extremely short, burst, low signal to noise ratio and severe phase fluctuation in the prior art, and realize high-reliability communication at extremely low speed by combining multi-frequency point blind detection with discrete fragment stream injection. The technical problems to be solved by the invention are realized by the following technical scheme: the invention provides a discrete fragment transmission method for underdensity meteor trail channels, which comprises the following steps: S1, a transmitting end establishes a communication link with a receiving end by adopting an active blind detection mechanism, and locks a communication frequency point; S2, after the communication link is established, the sending end deletes error correction codes to the original data to be transmitted to generate a coded data stream, and the coded data stream is segmented into a plurality of independent discrete segmente