PULSE INTERFERENCE CANCELLING SYSTEM FOR SPREAD SPECTRUM SIGNALS

摘要

Cancellation of pulse interference with no loss in the received level of the desired signal is obtained for a spread spertrum system which utilizes orthogonal multiplexed noise codes which when orthogonally multiplexed, matched filter detected and linearly added, compress to a lobeless impulse. The noise codes are comprised of binary noise codes which compress to a code bit width ?. The pulse interference is eliminated by means of a variable delay line and a linear adder coupled to the output of a linear adder which operates in combination with a pair of matched filters to provide a lobeless impulse signal. The delay line is varied to provide a 180.degree. phase shift for any pulse interference signal which occurs in time coincidence with the lobeless impulse. The original and phase shifted pulse interference signals are added together in the 1inear adder and in the process cancel one another while leaving the lobeless impulse signal with no reduction in signal amplitude.