Method and apparatus for cancellation of interference from a spread spectrum phase lock loop
AssigneeEntropic Communications, Inc.
InventorsChi-ping Nee, Branislav Petrovic
Life of this patent
Estimating the term…
Abstract
Systems and methods for provided for reducing interference caused by leakage of signals generated by a spread spectrum phase lock loop (SS PLL). Output of SS PLL may be processed to reduce interference. For example, a sinusoidal spreading signal may be used to spread the output of the SS PLL. A notch filter tracks the frequency of the output of the SS PLL to steer the notch in the filter to the instantaneous frequency output from the SS PLL, thus allowing the notch filter to be placed in the path of signals that have unwanted leakage from the SS PLL.
Claims21
1-11. (canceled)
A system comprising:
- a signal mitigation module;
- and
- a spread spectrum phase lock loop comprising:
- a voltage controlled oscillator (VCO);
- an adjuster operable to apply an adjustment to output of the VCO;
- a frequency source;
- a controller operable to generate control voltage for the VCO based on output of the frequency source and output of the adjuster;
- and
- a sinusoidal wave generator operable to generate at least a first output and a second output, wherein the first output is applied to at least one other component of the spread spectrum phase lock loop and the second output is applied to the signal mitigation module;
- wherein:
- the signal mitigation module is operable to process output of the spread spectrum phase lock loop, based on output of the sinusoidal wave generator, to reduce interference.
A method comprising:
- generating spread spectrum signal via a spread spectrum phase lock loop, the generating comprising:
- controlling voltage of a voltage controlled oscillator (VCO) that generates an output corresponding to said spread spectrum signal, wherein the controlling is based on output of a frequency source and output corresponding to applying adjustment to output of the VCO;
- processing the spread spectrum signal to reduce interference caused by the spread spectrum phase lock loop;
- and
- generating via a sinusoidal wave generator at least a first output and a second output,
- wherein the first output is applied during generating the spread spectrum signal via the spread spectrum phase lock loop, and the second output is applied during the processing of the spread spectrum signal.
Dependencies are inferred from the claim text.