SINUSOIDAL M-ARY ORTHOGONAL KEYED DECODING

Abstract

A spread spectrum communications system is described for recovering data from a signal having a first carrier frequency modulated by one of at least four phase modulations, each phase modulation orthogonal to one another and the signal further modulated by a predetermined spreading function incorporating a frequency synthesizer for generating a plurality of frequencies, including one of the phase modulations, a plurality of mixers, a combiner, a broadband convolver, a second combiner coupled to a reference signal generator for generating respective orthogonal modulations on spaced apart carrier frequencies, a power divider coupled to the output of the convolver and filters each having a frequency passband for recovering or separating the output signals of the convolver. The invention overcomes the problem of additional hardware complexity to accomodate Walsh orthogonal functions and of requiring a plurality of broadband convolvers to decode a plurality of orthogonal modulations of lesser bandwidth.

Source: Google Patents

35 USC §181 Secrecy Order

Inventor

• 1LEO A. KERR