Signal transmission method suitable for FSO physical layer network coding

Abstract

The invention relates to the technical field of laser communication, in particular to a signal processing and transmitting method suitable for FSO physical layer network coding. The invention aims atsolving the problem of large integer multiples of frequency offset in the prior art. The technical scheme of the invention is as follows: the method comprises the following steps: frequency offset estimation values of the signals A and the signals B are respectively solved by utilizing a preamble sequence designed in a staggered manner; a mean value of two estimated values is compensated for the superposed signal; due to the existence of A and B paths of residual frequency offsets, a common phase ej2pi delta can be regarded to be superposed between two adjacent OFDM symbols; wherein the size of the common phase is related to the size delta of the residual frequency offset, on the basis, a channel estimation value is obtained by utilizing the block pilot frequency, and all data block sequence superposed signals after the block pilot frequency can be further calculated by combining the common phase value brought by the frequency offset. The method is used for solving the problems of FSOsystem physical layer network coding frequency offset estimation and channel estimation.

Description

technical field [0001] The invention relates to the technical field of laser communication, and more specifically relates to a signal processing and transmission method suitable for FSO physical layer network coding. Background technique [0002] In the traditional relay mode of the FSO (Free Space Optical Communication) system, the relay satellite needs to carry two sets of independent signal transceiver equipment to complete the receiving-storage-forwarding process of the two signals. When the network becomes more complex, the number of transceiver devices that relay satellites need to carry increases, resulting in further increases in power consumption and quality. In order to reduce the load of relay satellites, such as figure 1 and figure 2 As shown, using OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) physical layer network coding technology is one of the potential solutions to solve this contradiction. [0003] The FSO...

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Problems solved by technology

[0004] Aiming at the problem of relatively large integer frequency offset in the prior art, the present invention provides a signal transmission method suitable for FSO physical layer network coding. Since the downlink stage of physical layer network coding is basically the same as that of point-to-point communication, the present invention The inventive design will focus on the reception of the uplink phase of the signal

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