Adaptive Encoding and Decoding Method Under the Plasma Sheath Based on Channel Feedback

Abstract

The invention discloses an adaptive coding and decoding method under plasma sheath based on channel feedback and mainly solves the problem that in an existing communication mode, under the condition that a dynamic plasma sheath has depth attenuation influences on signals, the reliable transmission of important information cannot be realized. The realization scheme comprises the steps that 1, a transmitting antenna standing wave ratio of an aircraft is taken as channel feedback quantity and a corresponding relationship between the standing wave ratios and channel communication quality is established; 2, on the basis of the advantages of fountain code unidirectional link communication, classified coding is carried out on to-be-transmitted information in an LT coding mode of a fountain code according to a windowing rule distribution function, and the information classification number, the windowing rule distribution function and a coding packet length are adjusted in real time according to the channel communication quality, thereby realizing key protection of the important information; and 3, pseudo code coding is carried out on a fountain code coding packet. According to the method,a utilization rate of the coding packet and the channel transmission reliability are improved, and the method can be applied to telemetry and telecontrol communication of the aircrafts such as a hypersonic aircraft and a reentry aircraft which are packaged by the plasma sheaths in a near space.

Description

technical field [0001] The invention belongs to the field of near-space measurement and control communication, and relates to an adaptive encoding and decoding method, which can be used for reliable signal transmission of re-entry aircraft and near-space aircraft covered by plasma sheaths. Background technique [0002] During the flight of a re-entry vehicle or a high-speed vehicle in near space, the airframe rubs violently with the air, which will generate a plasma sheath, resulting in deterioration of communication quality, increase in bit error rate, increase in time delay, and in severe cases, the information link will be interrupted, forming a The so-called "black barrier" phenomenon. [0003] In recent years, the main measures that have been widely recognized as promising to address this problem are as follows: [0004] 1. Increase the carrier frequency. This measure can increase the transmission of electromagnetic waves, and with the maturity of wide bandgap semicon...

AI Technical Summary

Problems solved by technology

But reducing the symbol rate is at the expense of the transmission rate

However, the channel capacity of a near-space vehicle or a reentry vehicle varies greatly during the whole flight. If the low symbol rate is always used for communication, the transmission efficiency is very low.

Moreover, in the traditional communication process, all information is transmitted in order, and low-efficiency transmission will not be able to guarantee the priority and reliable transmission of key information such as aircraft attitude control.

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