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US 7,073,113 B2Granted
Adaptive sigma-delta modulation with improved dynamic range
AssigneeThe Regents of the University of California
InventorsAli H. Sayed, Mansour A. Aldajani
Life of this patent
Estimating the term…
Abstract
An adaptive sigma-delta modulation and demodulation technique, wherein a quantizer step-size is adapted based on estimates of an input signal to the quantizer, rather than on estimates of an input signal to the modulator.
Claims22
An apparatus for adaptive sigma-delta modulation, comprising:
- (a) a summing junction for comparing an analog input signal x(n) to an encoding signal v(n) to generate an error signal e(n) representing a difference between the analog input signal x(n) and the encoding signal v(n);
- (b) a noise shaping filter for filtering the error signal e(n) to generate a signal p(n);
- (c) an absolute value block for generating an absolute value of the signal p(n);
- (d) a first one-bit quantizer for converting the signal p(n) into a binary output signal y(n);
- (e) an adapter for generating a scaling signal d(n) for scaling a step-size of the first one-bit quantizer using an estimation of the absolute value of the signal p(n), wherein the adapter comprises:
- (1) a summing junction for subtracting the scaling signal d(n) from the absolute value of the signal p(n) to generate an output signal;
- (2) a second one-bit quantizer for converting the output signal from the summing junction into a binary sequence signal q(n);
- (3) an integrator for integrating the binary sequence signal q(n);
- and
- (4) an exponential term block for converting the integrated binary sequence signal q(n) to the scaling signal d(n);
- and
- (f) a multiplier for multiplying the binary output signal y(n) by the scaling signal d(n) to generate the encoding signal v(n).
9 more elements
A method for adaptive sigma-delta modulation, comprising:
- (a) comparing an analog input signal x(n) to an encoding signal v(n) at a summing junction to generate an error signal e(n) representing a difference between the analog input signal x(n) and the encoding signal v(n);
- (b) filtering the error signal e(n) using a noise shaping filter to generate a signal p(n);
- (c) generating an absolute value of the signal p(n) at an absolute value block;
- (d) converting the signal p(n) into a binary output signal y(n) using a first one-bit quantizer;
- (e) generating a scaling signal d(n) at an adapter for scaling a step-size of the first one-bit quantizer using an estimation of the of the absolute value of the signal p(n) further comprising;
- (1) subtracting the scaling signal d(n) from the absolute value of the signal p(n) at a summing junction to generate an output signal;
- (2) converting the output signal from the summing junction into a binary sequence signal q(n) using a second one-bit quantizer;
- (3) integrating the binary sequence signal q(n) using an integrator and
- (4) converting the integrated binary sequence signal q(n) to the scaling signal d(n) using an exponential term block;
- and
- (f) multiplying the binary output signal y(n) by the scaling signal d(n) at a multiplier to generate the encoding signal v(n).
8 more elements
An apparatus for adaptive sigma-delta demodulation, comprising:
- (a) an adapter for converting a binary sequence signal q(n) received from an adaptive sigma-delta modulator to a scaling signal d(n), wherein the binary sequence signal q(n) is generated by a one-bit quantizer at the modulator and the adapter includes an integrator for integrating the binary sequence signal q(n) and an exponential term block for converting the integrated binary sequence signal q(n) to the scaling signal d(n);
- (b) a multiplier for multiplying a binary output signal y(n) received from the adaptive sigma-delta modulator by the scaling signal d(n) to generate an encoding signal v(n);
- and
- (c) a low-pass filter for filtering the encoding signal v(n) and for generating a signal {circumflex over (x)}(n), which is a re-creation of an analog input signal x(n) to the modulator.
1 more element
A method for adaptive sigma-delta demodulation, comprising:
- (a) converting a binary sequence signal q(n) received from an adaptive sigma-delta modulator to a scaling signal d(n) using an adapter, wherein the binary sequence signal q(n) is generated by a one-bit quantizer at the modulator and the adapter includes an integrator for integrating the binary sequence signal q(n) and an exponential term block for converting the integrated binary sequence signal q(n) to the scaling signal d(n);
- (b) multiplying a binary output signal y(n) received from the adaptive sigma-delta modulator by the scaling signal d(n) at a multiplier to generate an encoding signal v(n);
- and
- (c) filtering the encoding signal v(n) and generating a signal {circumflex over (x)}(n), which is a re-creation of an analog input signal x(n) to the modulator, At a low-pass filter.
1 more element
Dependencies are inferred from the claim text.