PSK-FSK spread spectrum modulation/demodulation

Claim 2

A communications system comprising: a frequency synthesizer for outputting m different frequency signals having frequency spacings Delta f between adjacent frequency signals; selector means for receiving m-ary data symbols and for selecting a different one of said m frequency signals for each unique data symbol of said m-ary data symbols that is received; spread spectrum means for generating an n-ary sequence of symbols, the symbol period being TSS, and for modulating the selected frequency signals to produce n-ary phase shift modulated signals where the frequency spacings Delta f between adjacent n-ary phase shift modulated signals are equal, and

Claim 3

The system of claim 1 wherein said spread spectrum means comprises: a binary sequence generator connected to said frequency synthesizer; a binary to n-ary converter connected to said binary sequence generator; an n-ary phase shift modulator connected to said binary to n-ary converter.

Claim 4

The system of claim 1 wherein said means for transmitting signals at carrier frequencies comprises: an up-converter connected to said n-ary phase shift modulator; and a transmitter amplifier connected to said up-converter.

Claim 5

The system of claim 1 wherein said receiver means comprises: first means for converting said carrier frequency signals to receiver frequency signals having frequencies fr + k Delta f where 0 < or = k < or = (m-1); and second means connected to said first means for determining which data symbols were transmitted.

Claim 6

The system of claim 4 wherein said second means comprises: a plurality of filters connected to said first means; a plurality of envelope detectors connected to said plurality of filters and; decision means connected to said plurality of envelope detectors.

Claim 7

The system of claim 4 wherein said second means comprises: a plurality of correlators connected to said first means; a plurality of envelope detectors connected to said plurality of correlators; and decision means connected to said plurality of correlators.

Claim 10

The method of spread spectrum communication of claim 7 further comprising the steps of: receiving said signals at carrier frequencies; and demodulating said signals at carrier frequencies to obtain the original data symbols.

Claim 11

A spread spectrum modulator comprising: a frequency synthesizer for outputting m different frequency signals having frequency spacings Delta f between adjacent frequency signals; selector means for accepting m-ary data symbols and for selecting a different one of said m frequency signals for each unique data symbol of said m-ary data symbols that is accepted; spread spectrum means for generating an n-ary sequence of symbols, the symbol period being TSS, and for modulating the selected frequency signals to produce n-ary phase shift modulated signals, where the frequency spacings Delta f between adjacent n-ary phase shift modulated signals are equal, and

Claim 12

A spread spectrum modulator comprising: a frequency synthesizer for outputting m different frequency signals having frequency spacings Delta f between adjacent frequency signals; selector means for accepting m-ary data symbols and for selecting a different one of said m frequency signals for each unique data symbol of said m-ary data symbols that is accepted; spread spectrum means for generating an n-ary sequence of symbols, the symbol period being TSS, and for modulating the selected frequency signals to produce n-ary phase shift modulated signals, where the frequency spacings Delta f between adjacent n-ary phase shift modulated signals are equal, and