Time-frequency filtering of interferences in spread spectrum communications

A novel technique to excise single and multi-component chirp-like interferences in direct sequence spread spectrum communications is proposed. The received signal is decomposed into its time-frequency (TF) functions using an adaptive signal decomposition algorithm and the TF functions are mapped onto the TF plane. The TF plane is optimized and treated as an image, and the interference represented in the TF plane is detected using the Hough-Radon transform (HRT). Simulation results with synthetic models have shown successful performance for the excision of linear and non-linear chirp interferences. The method has shown immunity to both white noise and multiple interferences even under very low SNR conditions of -10 dB.