Modulation parameter estimation method for OFDM signals under Alpha stable distribution noises

Abstract

The invention belongs to the technical field of communication signal modulation analysis under non-Gaussian noise environments, and discloses a modulation parameter estimation method for OFDM signalsunder Alpha stable distribution noises. The method comprises the following steps: performing nonlinear transformation on received OFDM signals, and calculating generalized cyclic autocorrelation functions of the signals; extracting specific cyclic frequency sections of the generalized cyclic autocorrelation functions, and implementing available symbol length estimation on the OFDM signals by searching spectral peaks of the specific cyclic frequency sections; and extracting specific time delay sections based on available symbol length estimation, and implementing symbol length estimation on theOFDM signals by searching spectral peaks of the specific time delay sections. Under Alpha stable distribution background noises, when the mixed signal-to-noise ratio is greater than -1dB, the root-mean-square error of available symbol length estimation of the OFDM signals is close to 0, and when the mixed signal-to-noise ratio is greater than 3dB, the root-mean-square error of symbol length estimation of the OFDM signals is close to 0.

Description

technical field [0001] The invention belongs to the technical field of communication signal modulation analysis in a non-Gaussian noise environment, and in particular relates to a method for estimating OFDM signal modulation parameters in Alpha stable distributed noise. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM, Orthogonal Frequency Division Multiple) technology uses orthogonal subcarriers for data transmission, which not only improves frequency band utilization but also helps reduce intersymbol interference, and has been widely used in modern military and civilian communications. In the third-party non-cooperative reception scenario, the third party cannot know the modulation parameters of the received signal in advance, and needs to accurately estimate the modulation parameters of the received signal before demodulating and recovering the message information. For OFDM modulation, modulation parameters such as the useful symbol period an...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a method for estimating OFDM signal modulation parameters in an Alpha stable distributed noise environment, to solve the problem of signal modulation parameters in application fields such as communication signal monitoring in environments with impulse noise such as shallow sea acoustics

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