Interference excision in direct sequence spread spectrum communication using linear time varient filtr

The time-frequency (TF) filter design of non-stationary signals especially chirp signals are studied in the fractional domain. The design of TF/ linear time variant (LTV) filter is implemented as a non-overlapping short time fractional Fourier transform (STFRFT). The first step of our method involves detecting the presence of a multi component linear FM interference and correctly estimating its orientation in the time-frequency plane using cross spectral estimation of signal parameter via rotational invariant technique. This paper introduces a novel algorithm to excise single and multicomponent chirp-like interferences in direct sequence spread spectrum (DSSS) communication. The proposed method excises the interference with high interference power condition, and technique could be easily extended to any kind of chirp interference with little modification.