Waveform Reconstruction of DSSS Signal Based on VAE-GAN

Abstract

The complex electromagnetic environment will limit the efficacy of communication equipment. It is critical to construct a complex electromagnetic environment to test communication equipment in order to maximize its capability. One of the most important methods for constructing a complex electromagnetic environment is signal reconstruction. This paper proposes a VAE-GAN-based method for reconstructing direct sequence spread spectrum (DSSS) signals. In this method, the deep residual shrinkage network (DRSN) and self-attention mechanism are added to the encoder and discriminator of VAE-GAN. In feature learning, the DRSNs can reduce the redundant information caused by noise in the collected signal. The self-attention mechanism can establish the long-distance dependence between the input sequences, making it easier for the network to learn the samples’ pseudonoise (PN) sequence features. In addition, feature loss is applied to the encoder and generator to improve network stability during training. The results of the experiments indicate that this method can reconstruct DSSS signals with the characteristics of the target signal.

A Fast Estimation Algorithm for Parameters of Multiple Frequency-Hopping Signals Based on Compressed Spectrum Sensing and Maximum Likelihood

“…A schematic diagram of the ETHM is shown in Figure 1. In Figure 1, L is the total number of samples, and the rest of the notations are annotated under (1). The ETHM is composed of two FH signal models and two received signal models.…”

“…Initially, in radio communication, the signal is modulated by a transmitter into a constant-frequency radio frequency (RF) signal, which is then sent to a receiver. However, constant-frequency RF signals are very susceptible to interference from the complex surrounding electromagnetic environment and to eavesdropping by third parties [1,2]. In this case, frequency-hopping signals have gradually replaced constant-frequency RF signals due to their strong anti-interference capability and good confidentiality and are widely used for military communications and remote control [3][4][5][6][7].…”