Noiselike amplitude and phase modulation coding for spread spectrum transmissions
AssigneeThe Bendix Corporation
InventorEdgar H. German, Jr.
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Abstract
A plurality of binary pseudo noise generators are used to develop a Gaussian code that appears thermal noiselike in both amplitude and phase. Half of the pseudo noise generators are provided in an in-phase section and half in a quadrature section, with each said generator output being mixed with data to be transmitted and applied to modulate a carrier, the outputs from the various sections being combined for transmission. A receiver having the same number of pseudo noise generators and generating the same code synchronously demodulates the received data.
Claims10
Means for providing a signal having noiselike amplitude and phase modulation coding for spread spectrum applications comprising:
- at least a first plurality of pseudo noise generators, each of which generates a predetermined noiselike code signal;
- a source of data;
- first means for adding said data to each said noiselike code signal to produce a first plurality of data modulated noiselike signals;
- a second plurality of pseudo noise generators, each of which generates a predetermined noiselike code signal;
- means for generating a first carrier frequency;
- means for shifting the phase angle of said carrier frequency by 90 degrees to provide a second carrier frequency;
- second means for adding said data to each said noiselike code signal from said second plurality of pseudo noise generators to provide a second plurality of data modulated noiselike signals;
- means for summing said first plurality of signals to provide a first sum signal,
- means for summing said second plurality of signals to provide a second sum signal;
- means for mixing said first carrier frequency with said first sum signal to generate an in-phase signal component,
- means for mixing said second carrier frequency with said second sum signal to generate a quadrature signal component;
- and,
- means for combining said in-phase signal component with said quadrature signal signal component.
Dependencies are inferred from the claim text.