A Time-Frequency Energy Squeeze Method Based on Estimating the Chip Rate of DSSS Signals

Area of Science:

• Electrical Engineering
• Signal Processing
• Wireless Communications

Background:

• Chip rate estimation is vital for signal detection and interference identification in non-cooperative wireless systems.
• Low signal-to-noise ratio (SNR) and channel fading significantly degrade the accuracy of traditional DSSS chip rate estimation methods.

Purpose of the Study:

• To propose an improved chip rate estimation method for direct-sequence spread spectrum (DSSS) signals specifically designed for low SNR environments.
• To enhance the accuracy and reliability of chip rate estimation in challenging wireless communication conditions.

Main Methods:

• A novel method based on time-reassigned multisynchrosqueezing transform energy squeeze is introduced.
• The technique involves selecting appropriate wavelet functions and reordering time details to concentrate wavelet coefficients, thereby improving time resolution and reducing noise.
• Performance is evaluated by comparing with traditional methods under varying information code lengths, spread spectrum code lengths, sequences, and modulation schemes.

Main Results:

• The proposed method demonstrates enhanced time resolution of signal energy and reduced noise interference.
• Improved accuracy in chip rate estimation for DSSS signals was observed, particularly in low SNR conditions.
• Validation through simulations and real DSSS signal data confirms the method's reliability and feasibility.

Conclusions:

• The developed time-reassigned multisynchrosqueezing transform method offers a robust solution for accurate DSSS chip rate estimation in low SNR environments.
• This advancement is crucial for improving signal detection and interference identification in non-cooperative wireless systems.
• The method's effectiveness is proven across various signal parameters and in real-world scenarios.