Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
118 words
A communication or measurement system including: A. a transmitter for transmitting a modulated signal, the transmitter including a first feedback shift register that produces a pseudo-random noise signal that is used to modulate a message signal; B. a receiver for receiving the modulated message signal, the receiver including a second feedback shift register for reproducing the pseudo-random noise signal from the received modulated signal and using the noise signal to recover the message signal from the received signal, the second feedback shift register being characterized by a non-chaotic expression that is associated with the expression that governs the first feedback shift register and has stable fixed points at integer values and unstable fixed points at 1/2 integer values.
Claim 2
Dependent Claim
118 words
A communication or measurement system including: A. a transmitter for transmitting a modulated signal, the transmitter including a first feedback shift register that produces a pseudo-random noise signal that is used to modulate a message signal; B. a receiver for receiving the modulated message signal, the receiver including a second feedback shift register for reproducing the pseudo-random noise signal from the received modulated signal and using the noise signal to recover the message signal from the received signal, the second feedback shift register being characterized by a non-chaotic expression that is associated with the expression that governs the first feedback shift register and has stable fixed points at integer values and unstable fixed points at 1/2 integer values.
Claim 3
Dependent Claim
29 words
The communication system of claim 1, wherein the second feedback shift register is characterized by a function that has at integer values a slope of magnitude less than 1.
Claim 4
Dependent Claim
89 words
The system of claim 1, wherein i. the first feedback shift register is characterized by the following update expression: ##EQU8## where the α i 's are the coefficients of a maximum length polynomial and x n-i is the state of the (n-i) th stage of the register, and ii. the second feedback shift register is characterized by the following update expression: ##EQU9## where the α i 's are the coefficients of the maximum length polynomial and y n-1 is the state of the (n-i) th stage of the register.
Claim 5
Dependent Claim
67 words
The system of claim 2 further including a coupling circuit that produces an update signal, y' n , for the second shift register, y' n =(1-ε)y n +εS n , where ε is a coupling factor selected between 0 and 1 and S n is a sample of the received signal, the coupling circuit applying the update signal to a first stage of the second shift register.
Claim 6
Dependent Claim
32 words
The system of claim 4, wherein the coupling factor is set to a value relatively close to 1 until the second shift register synchronizes to the received signal, and is thereafter decreased.
Claim 7
Dependent Claim
84 words
The system of claim 3, further including a coupling circuit that produces a signal y' n =(1-ε)y n +εsgnS n , where ε is a coupling factor selected between 0 and 1 and sgnS n is the sign of a sample of the received signal, the coupling circuit updating the second feedback shift register using the signal y' n if the amplitude of the received signal sample does not exceed a signal value that represents a binary value by more that a predetermined amount.
Claim 8
Dependent Claim
145 words
An analog feedback shift register for use in a communication or measurement system, the shift register including: A. a plurality of stages connected together such that the contents of one stage are used to update a next stage; and B. means for producing a feedback signal by combining the contents of the stages in accordance with the following expression: ##EQU10## where the α i 's are the coefficients of the maximum length polynomial and y n-1 is the state of the (n-i) th stage of the register, and C. coupling means for coupling an update signal to a first stage of the register, the coupling circuit adding (1-ε)y n and εS n to produce the update signal y' n =(1-ε)y n +εS n , where ε is a coupling factor selected between 0 and 1 and S n is a sample of a received signal.
Claim 9
Dependent Claim
145 words
An analog feedback shift register for use in a communication or measurement system, the shift register including: A. a plurality of stages connected together such that the contents of one stage are used to update a next stage; and B. means for producing a feedback signal by combining the contents of the stages in accordance with the following expression: ##EQU10## where the α i 's are the coefficients of the maximum length polynomial and y n-1 is the state of the (n-i) th stage of the register, and C. coupling means for coupling an update signal to a first stage of the register, the coupling circuit adding (1-ε)y n and εS n to produce the update signal y' n =(1-ε)y n +εS n , where ε is a coupling factor selected between 0 and 1 and S n is a sample of a received signal.
Claim 10
Dependent Claim
33 words
The communication system of claim 6, wherein the coupling factor is set to a value relatively close to 1 until the analog shift register synchronizes to the received signal, and is thereafter decreased.
Claim 11
Dependent Claim
140 words
An analog feedback shift register for use in a communication system, the shift register including: A. a plurality of stages connected together such that the contents of one stage are used to update a next stage; and B. means for producing a feedback signal by combining the contents of the stages in accordance with the following: ##EQU11## where the α i 's are the coefficients of the maximum length polynomial and y n-1 is the state of the (n-i) th stage of the register, and C. coupling means for coupling an update signal y' n to a first stage of the register, the coupling circuit using as an update y' n =(1-ε)y n +εsgnS n , where ε is a coupling factor selected between 0 and 1 and sgnS n is the sign of a sample of a received signal.
Claim 12
Dependent Claim
140 words
An analog feedback shift register for use in a communication system, the shift register including: A. a plurality of stages connected together such that the contents of one stage are used to update a next stage; and B. means for producing a feedback signal by combining the contents of the stages in accordance with the following: ##EQU11## where the α i 's are the coefficients of the maximum length polynomial and y n-1 is the state of the (n-i) th stage of the register, and C. coupling means for coupling an update signal y' n to a first stage of the register, the coupling circuit using as an update y' n =(1-ε)y n +εsgnS n , where ε is a coupling factor selected between 0 and 1 and sgnS n is the sign of a sample of a received signal.