Finite block length covert communication implementation method based on channel estimation

Abstract

The invention provides a finite block length covert communication implementation method based on channel estimation. In the past, studies on covert communication in a fading channel are supposed thatthe channel is known, or channel estimation is avoided through a channel inversion power control method. However, in practice, channel estimation is inevitably performed in a fading channel due to theideality of channel reciprocity hypothesis. In conventional channel estimation, the optimal pilot number is equal to the number of transmission antennas, but in covert communication, the conclusion may not be established any more. In order to improve the reliability of covert communication, a minimum mean square error estimation method is used for estimating a channel, and the optimal pilot frequency number, the optimal transmitting power, the optimal data number and the optimal transmitting power are designed under the covert constraint condition to maximize the effective rate. Meanwhile, due to the fact that previous studies are generally concentrated on analysis of infinite block lengths, but symbols of the limited block lengths are usually sent in practice, hidden communication underthe limited block lengths is studied through the method.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to a method for realizing covert communication with limited block length based on channel estimation. Background technique [0002] With the rapid development of mobile communications, it is becoming more and more important to protect the privacy of information transmission. However, in the traditional method of ensuring information security, the information content itself is often protected, such as encryption. But in this way, it is easy for the eavesdropper to know that the secret information is being transmitted at this time, and it will be easier to arouse the eavesdropper's interest in deciphering. [0003] The purpose of covert communication is to hide the process of information transmission, so that the watchman does not know that there is information transmission, that is, to ensure that the watchman detects that the information is being transmitted with a v...

AI Technical Summary

Problems solved by technology

However, in practice, the assumption of channel reciprocity is too ideal, which inevitably estimates the channel

At the same time, most of the research on covert communication assumes infinite block length, but in practice it is often necessary to send symbols with finite block length

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