Anti-jam communications having selectively variable peak-to-average power ratio including a chaotic constant amplitude zero autocorrelation waveform
First Claim
1. A method for generating an adaptive PAPR chaotic communication signal, comprising:
- phase modulating a carrier signal with data to form an information signal;
generating a chaotic spreading sequence based on a chaotic number sequence, said chaotic spreading sequence having a magnitude that is constant and having a variable arbitrary phase angle comprising phase values which are uniformly distributed over a predetermined range of angles;
forming a spread spectrum signal by multiplying said information signal by said chaotic spreading sequence, said spread spectrum signal having a constant amplitude and a zero autocorrelation;
detecting current operating conditions of a communication environment; and
dynamically transforming said spread spectrum signal with a first PAPR to a chaotic signal with a second PAPR having a higher value than the first PAPR, based on said current operating conditions of the communication environment.
1 Assignment
0 Petitions
Accused Products
Abstract
A spread spectrum communication system includes a channel encoder configured for modulating a carrier signal with data to form an information signal. A spreading sequence generator is configured for generating a spreading sequence having a phase angle dependent upon a chaotic sequence and contiguously distributed over a predetermined range. The chaotic sequence also has a magnitude which is selectively dependent upon the pseudo-random number or chaotic sequence. The invention also includes a multiplier configured for forming a spread spectrum signal by multiplying the information signal by the spreading sequence. The spreading sequence generator is responsive to a magnitude control signal for controlling the selective dependency of said magnitude. The magnitude can be constant to form a constant amplitude zero autocorrelation signal. Alternatively, the magnitude can be allowed to vary in selectively controlled chaotic or pseudo-random manner to vary a peak to average power ratio.
205 Citations
29 Claims
-
1. A method for generating an adaptive PAPR chaotic communication signal, comprising:
-
phase modulating a carrier signal with data to form an information signal; generating a chaotic spreading sequence based on a chaotic number sequence, said chaotic spreading sequence having a magnitude that is constant and having a variable arbitrary phase angle comprising phase values which are uniformly distributed over a predetermined range of angles; forming a spread spectrum signal by multiplying said information signal by said chaotic spreading sequence, said spread spectrum signal having a constant amplitude and a zero autocorrelation; detecting current operating conditions of a communication environment; and dynamically transforming said spread spectrum signal with a first PAPR to a chaotic signal with a second PAPR having a higher value than the first PAPR, based on said current operating conditions of the communication environment. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method for constructing an adaptive communication signal robust in the presence of natural or man-made interference, comprising:
-
modulating a carrier signal with data to form an information signal; generating a chaotic spreading sequence based on a chaotic number sequence; selecting said chaotic spreading sequence to have a pseudo-randomly or chaotically variable magnitude and a chaotically varying arbitrary phase angle including phase values which are band limited and distributed over a predetermined range of angles; forming a spread spectrum signal by multiplying said information signal by said chaotic spreading sequence, said spread spectrum signal having a peak to average power ratio (PAPR); and detecting current operating conditions of a communication environment; and dynamically transforming said spread spectrum signal with a first PAPR to a chaotic signal with a second PAPR having a higher value than the first PAPR, based on said current operating conditions of the communication environment; wherein said spread spectrum signal is dynamically transformed to said chaotic signal at least by selectively varying an average deviation of said pseudo-randomly or chaotically variable magnitude of said chaotic spreading sequence. - View Dependent Claims (13, 14, 15, 16)
-
-
17. A spread spectrum communication system, comprising:
-
a channel encoder configured to phase modulate a carrier signal with data to form an information signal; a spreading sequence generator configured to generate a spreading sequence having a phase angle dependent upon a chaotic number sequence and a magnitude which is selectively dependent upon a pseudo-random number or chaotic sequence; a multiplier configured to form a spread spectrum signal by multiplying said information signal by said spreading sequence; detecting current operating conditions of a communications environment; and dynamically transforming said spread spectrum signal with a first PAPR to a chaotic signal with a second PAPR having a higher value than the first PAPR, based on said current operating conditions of said communications environment; wherein said spreading sequence generator is responsive to a control signal for controlling said selective dependency of said magnitude. - View Dependent Claims (18, 19, 20, 21, 22, 23, 25, 26, 27, 28)
-
-
24. A spread spectrum communication system, comprising:
-
a channel encoder configured to phase modulate a carrier signal with data to form an information signal; a spreading sequence generator configured to generate a spreading sequence having a phase angle dependent upon a chaotic number sequence and a magnitude which is selectively dependent upon a pseudo-random number or chaotic sequence, said spreading sequence generator responsive to a control signal for controlling said selective dependency of said magnitude; and a multiplier configured to form a spread spectrum signal by multiplying said information signal by said spreading sequence; a digital modulator configured to translate said spread spectrum signal from a first IF frequency to second IF frequency; a digital-to-analog converter configured to convert said spread spectrum signal to a first analog IF spread spectrum signal; an IF to RF translator configured to convert said first analog IF spread spectrum signal to an analog RF spread spectrum signal suitable for transmission; a receiver configured to receive said analog RF spread spectrum signal, convert said analog RF spread spectrum signal to a second analog IF spread spectrum signal, and digitize said second analog IF spread spectrum signal; a de-spreading sequence generator configured to digitally generate a de-spreading sequence identical to said spreading sequence; a correlator configured to de-spread said second analog IF spread spectrum signal using said de-spreading sequence to recover said information signal; a channel decoder configured to de-modulate said information signal to recover said data; and at least one digital data synchronizer at said receiver configured to utilize a predetermined set of acquisition data for synchronizing said de-spreading sequence with said spreading sequence.
-
-
29. A spread spectrum communication system, comprising:
-
a channel encoder configured to modulate a carrier signal with data to form an information signal; a spreading sequence generator configured to generate a spreading sequence having a constant magnitude and an arbitrary phase angle dependent upon a chaotic number sequence and distributed over a predetermined range of angles; and a multiplier configured to form a spread spectrum signal by multiplying said information signal by said spreading sequence, said spread spectrum signal being a constant amplitude, zero autocorrelation spread spectrum signal; detecting current operating conditions of a communications environment; and dynamically transforming said spread spectrum signal with a first PAPR to a chaotic signal with a second PAPR having a higher value than the first PAPR, based on said current operating conditions of the communication environment.
-
Specification