摘要:
A system and method are disclosed for securely transmitting and receiving a signal. A nonlinear keying modulator is used in the transmitter to encrypt the signal using a nonlinear keying modulation technique. A nonlinear keying demodulator is used in the receiver to decrypt the signal.
摘要:
A system and method are disclosed for securely transmitting and receiving a signal. A nonlinear keying modulator is used in the transmitter to encrypt the signal using a nonlinear keying modulation technique. A nonlinear keying demodulator is used in the receiver to decrypt the signal.
摘要:
A digital signal processing system comprising: an input terminal to receive an input signal that includes a distorted component and an undistorted component, the input signal having a sampling rate of R; and an adaptive self-linearization module coupled to the input terminal, to perform self-linearization based at least in part on the input signal to obtain an output signal that is substantially undistorted, wherein: the adaptive self-linearization module is to generate a replica distortion signal that is substantially similar to the distorted component, the generation being based at least in part on a target component having a sampling rate of R/L, L being an integer greater than 1; the adaptive self-linearization module includes a first digital signal processor (DSP) that is adapted to obtain a filter transfer function that approximates a system distortion transfer function, and a second DSP that is configured using configuration parameters of the first DSP.
摘要:
A method of signal processing comprises receiving an unknown input signal that includes a distorted component and an undistorted component, the unknown input signal having a sampling rate of R; and performing self-linearization based at least in part on the unknown signal to obtain an output signal that is substantially undistorted, including by generating a replica distortion signal that is substantially similar to the distorted component, the generation being based at least in part on a target component having a sampling rate of R/L, L being an integer greater than 1.A digital signal processing system comprises an input terminal configured to receive an unknown input signal that includes a distorted component and an undistorted component, the unknown input signal having a sampling rate of R; and an adaptive self-linearization module coupled to the input terminal, configured to perform self-linearization based at least in part on the unknown input signal to obtain an output signal that is substantially undistorted, wherein the adaptive self-linearization module includes a replica distortion signal generator configured to generate a replica distortion signal that is substantially similar to the distorted component, the generation being based at least in part on a target component having a sampling rate of R/L, L being an integer greater than 1.
摘要:
A digital signal processor (DSP) comprises an input terminal configured to receive an input, an adaptive nonlinear phase filter coupled to the input terminal, the adaptive nonlinear phase filter having a time-varying phase response, and an adaptive nonlinear amplitude filter coupled to the input terminal, the adaptive nonlinear amplitude filter having a time-varying amplitude response.A method of processing a signal comprises receiving the signal, sending the signal to an adaptive nonlinear phase filter, the adaptive nonlinear phase filter having a time-varying phase response, and sending the signal to an adaptive nonlinear amplitude filter, the adaptive nonlinear amplitude filter having a time-varying amplitude response.
摘要:
An adaptive nonlinear filtering system includes an adaptive filter module that is configured to generate relative location information pertaining to a relative location of an input signal within an input range; determine an input dependent filter parameter based at least in part on the relative location information; generate an output signal based at least in part on the input dependent filter parameter; and feed back a feedback signal that is generated based at least in part on the output signal and a target signal.
摘要:
A method of converting an input analog signal to a compensated digital signal comprises converting the input analog signal to an uncompensated digital signal, inputting the uncompensated digital signal to a distortion model, generating a modeled distortion signal based on the uncompensated digital signal, and subtracting the modeled distortion signal from the uncompensated digital signal to generate the compensated digital signal. A distortion compensating analog to digital converter (ADC) comprises an uncompensated ADC configured to convert an input analog signal to an uncompensated digital signal, and a compensation module coupled to the uncompensated ADC, configured to receive the uncompensated digital signal, generate a modeled distortion signal based on the uncompensated digital signal and subtract the modeled distortion signal from the uncompensated digital signal to generate the compensated digital signal.
摘要:
Methods and apparatus for efficiently communicating across an asymmetric digital subscriber loop are disclosed. According to one aspect of the present invention, a method for communicating between a computer in a central office and a remote computer across DSL communications links involves sending a first set of data from the central office computer across a first DSL communications link. The first DSL communications link couples the central office computer to a switch. The method also includes selecting a second DSL communications link, which couples the switch and the remote computer, and sending the first set of data from the switch to the remote computer across the second DSL communications link.
摘要:
A method and apparatus for performing blind mode decision feedback equalization with reduced convergence time. In operation, the decision feedback equalizer (DFE) of the invention receives a transmitted signal x(n) resulting from transmission of an input signal s(n) through a transmission channel and a receive filter. The apparatus includes a DFE feedback loop having an adaptive filter designed to converge rapidly and iteratively during blind mode decision feedback equalization to a best approximation A'(z) of the unknown, combined, transmission channel and receive filter transfer function A(z). In a preferred embodiment, the apparatus includes DFE circuitry for implementing a Widrow-Hoff least-mean-squared adaptation process, including circuitry for generating an input signal replica s'(n) and an error signal e(n) during each iteration of the adaptation process. In this embodiment, the adaptive filter adaptively generates N replica coefficients a'.sub.j (n), where j=1, 2, . . . , N, which define approximation A'(z), and a replica coefficient a'.sub.O (n) which is employed to update the error signal e(n).
摘要:
An adaptive distortion reduction system comprising: an input interface to receive a distorted signal comprising a distorted component and an undistorted component, the distorted component being at least in part attributed to an exogenous signal; and an adaptive distortion reduction module coupled to the input interface, to perform linearization based at least in part on the distorted signal and information associated with the exogenous signal, to obtain a corrected signal that is substantially similar to the undistorted component; wherein the adaptive self-linearization module includes: a first digital signal processor (DSP) that is adapted to obtain a filter transfer function that approximates a transfer function to be corrected; and a second DSP that is configured using configuration parameters of the first DSP.