US 9,071,314 B2 · Method and apparatus for cross polarization and cross satellite interference cancellation

Abstract

A method and apparatus in which a Tap-Weight Computer (TWC) calculates a Tap-Weight Vector (TWV). The TWV is coupled to a register in each of a plurality of adaptive filter modules. Each such adaptive filter module includes several adaptive filters that each include a tapped delay line. The input to the tapped delay line of each such adaptive filter is one of a plurality of potential interfering signals. The TWV controls the weighting of the outputs from the taps off the delay line. The weighted outputs from each tapped delay line are then subtracted from a received signal which potentially includes interference from the potential interfering signals. The TWC is multiplexed to each of the plurality of adaptive filters so that each adaptive filter is loaded with a TWV calculated by the TWC to reduce the amount of interference contributed by a particular potential interfering signal coupled to an input to that particular adaptive filter. In one embodiment, a plurality of such adaptive filter modules share the same TWC.

Claims19

Dependent claims

A method of cancelling interference from satellite signals received at approximately the same frequency as a desired satellite signal, comprising:

receiving a composite signal comprising:
a desired satellite signal at a frequency;
a first interfering satellite signal at approximately the frequency of the desired satellite signal;
and
a second interfering satellite signal at approximately the frequency of the desired satellite signal;
coupling a first register within a first adaptive filter to a tap-weight computer;
determining within the tap-weight computer an initial weight for each of several tapped outputs from the first interfering satellite signal;
loading from the tap-weight computer a first tap-weight vector into the first register to control the amount to be adjusted of interfering signal at each of the tapped outputs from the interfering satellite signal;
determining a first error correction of the composite signal based on the output of the first adaptive filter;
decoupling the first register and coupling a second register within a second adaptive filter to the tap-weight computer;
determining an initial weight for each of several tapped outputs from the second interfering satellite signal;
loading a second tap-weight vector into a register within a second adaptive filter to control the amount of interfering signal at each of the tapped outputs from the second interfering satellite signal;
and
determining a second error correction of the composite signal based on the output of the second adaptive filter.

11 more elements

A system for reducing satellite signal interference, comprising:

a receiver configured to receive a composite signal comprising a desired satellite signal and a plurality of interfering satellite signals, wherein the desired satellite signal and the plurality of interfering satellite signals are at approximately the same frequency;
a tap-weight computer (TWC) configured to compute a tap-weight vector (TWV) for each of the plurality of interfering satellite signals, wherein each TWV adjusts the magnitude and phase error of its respective interfering satellite signal;
a plurality of adaptive filters, each comprising:
a. a register into which a corresponding interfering satellite signal and TWV are coupled,
b. a tapped delay line through which a corresponding interfering satellite signal is clocked, said tapped delay line having a plurality of outputs, each output representing a term of said corresponding interfering satellite signal, each output being delayed a predetermined number of clock cycles from a next preceding output,
c. a plurality of multipliers connected to produce a product of a term of said corresponding TWV in said register and a respective one of said plurality of outputs to produce an output product, and
d. an adder to sum said output products to produce an error-correcting signal output, and
a plurality of subtractors for subtracting from said composite signal said error-correcting signal outputs of said plurality of adaptive filters to provide said desired satellite signal, wherein said TWC uses an algorithm to cause said TWVs to reduce interference from said interfering satellite signals in said desired satellite signal.

5 more elements

Dependencies are inferred from the claim text.

Method and apparatus for cross polarization and cross satellite interference cancellation

Life of this patent

Method and apparatus for cross polarization and cross satellite interference cancellation

Life of this patent

Abstract

Claims19