US 6,724,805 B1 · Nonlinear dynamic system for spread spectrum code generation and acquisition

Abstract

Nonlinear dynamic systems for generating and acquiring a spread spectrum signal pseudo-random noise (PN) signal are disclosed. An actuating signal is delayed by a first and second period to produce delayed actuating signals. A continuous, nonlinear function is applied to input that corresponds to the delayed actuating signals to produce an output signal. The function has values that correspond to the binary integer values of the mod 2 addition function of a linear feedback shift register, and a non-zero slope at those values. The output signal becomes a PN signal over time when it is fed back to the actuating signal. The output signal synchronizes with a spread spectrum reference input signal when it is superposed on the reference input signal to produce the actuating signal. The system may be incorporated into a transmitter or a receiver, either of which may be part of a larger communication system.

Claims33

Dependent claims

An analog feedback method for use in a communication or measurement system, the method comprising the steps of:

(a) delaying an actuating signal by a first period to produce a first delayed actuating signal;
(b) delaying the actuating signal by a second period to produce a second delayed actuating signal, wherein the second period is approximately an integer multiple of the first period;
(c) applying a continuous, nonlinear function to a first input that corresponds to the first delayed actuating signal and a second input that corresponds to the second delayed actuating signal to produce an output signal, wherein (i) the function has values that correspond to the binary integer values of a mod 2 addition function of a linear feedback shift register and (ii) the function has a non-zero slope at the values;
and
(d) feeding back the output signal to the actuating signal, whereby the output signal becomes a pseudo-random noise signal over time.

2 more elements

An analog feedback subsystem for use in a communication or measurement system, the subsystem comprising:

a delay element, the delay element delaying an actuating signal by a first period to produce a first delayed actuating signal and delaying the actuating signal by a second period to produce a second delayed actuating signal, wherein the second period is approximately an integer multiple of the first period;
a nonlinear element in signal communication with the delay element, the nonlinear element applying a continuous, non-linear function to a first input that corresponds to the first delayed actuating signal and a second input that corresponds to the second delayed actuating signal to produce an output signal, wherein (i) the function has values that correspond to the binary integer values of a mod 2 function of a linear feedback shift register and (ii) the function has a non-zero slope at the values;
and
a feedback connection creating signal communication between the nonlinear element and the delay element, the feedback connection communicating the output signal to the delay element, whereby the output signal becomes a pseudo-random noise signal over time.

1 more element

Dependencies are inferred from the claim text.

Nonlinear dynamic system for spread spectrum code generation and acquisition

Life of this patent

Nonlinear dynamic system for spread spectrum code generation and acquisition

Life of this patent

Abstract

Claims33