Technology Transfer SSC Pacific
Device for Removing Narrowband Interference

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System removes unwanted RF signals to improve wireless communications

The U.S. Navy seeks to commercialize U.S. Patent 7,277,475 (Narrowband interference excision device).


Narrowband interference is unwanted radio-frequency signals that disrupt the reception ability of wireless communication systems. These signals can be caused by electronic equipment such as computers or power sources and must be reduced or eliminated for reliable data reception. Hardware notch filtering, the most common interference removal method, is not ideal because it requires external references to the system and cannot remove strong interference. Additionally, notch filtering cannot adapt to abrupt changes in environment that makes it ineffective in some situations. An interference excision device that requires no external references and that operates in high-impulsive and high-interference environments would improve a wireless communication system’s data reception ability and could be particularly useful in medical instruments. The effect of interference on medical equipment is of concern due to its potential to obstruct the safe operation of life support or critical care equipment. With increasing use of both medical instruments susceptible to electro-magnetic interference (EMI) and of wireless technologies that cause EMI, better interference removal techniques are needed.

The Technology

SSC Pacific has developed a method and apparatus for removing interference in high-amplitude, impulsive environments without the need for external references. The method transforms the interference signal into frequency data and then calculates an average. The system uses the average to remove signals based on differences relative to the system average, which eliminates the need for an external reference. The frequency groups determined to be irrelevant are removed and the method determines whether to include average calculations in future determinations. The device can remove interference in wireless communication systems or in medical devices receiving interference from power sources.

Key Benefits

  • Improves data reception quality in wireless communication systems
  • System does not require external references
  • Adapts to noisy changes, removing short duration, high-amplitude interference
  • Could be used to remove AC interference (50/60 Hz) in medical instrument
  • Development Status

  • U.S. Patent issued: 7,277,475
  • DoD 5000 Series Technology Readiness Level 6: System/subsystem model or prototype demonstration in relevant environment
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    SD 859, July 2009. SSC Pacific, San Diego, CA 921525001. Approved for public release; distribution is unlimited.

    SSC Pacific
    Updated: 1/13/2015 8:23 AM EST   Published