Narrowband interference excision in the external controller of an implanted microstimulator network
First Claim
1. An external communication system for communicating with a limited energy body implanted wireless device that is substantially shielded from a narrowband interference source, wherein the external communication system is arranged to mitigate effects of narrowband interference signals from the narrowband interference source, the external communication system comprising:
- a receiver that is arranged to capture signals associated with a transmission from the limited energy body implanted device during a capture interval for the receiver, wherein a duration of the capture interval for the receiver is substantially greater than a transmit time associated with the transmission, wherein the captured signals include at least one member of the group consisting of;
a portion of a message from the limited energy body implanted device, narrowband interference signals, and noise signals;
a buffer that is arranged to store samples associated with the captured signals; and
a signal processor that is arranged to process the stored samples, wherein the signal processor is arranged to;
transform the stored samples from at least a portion of the capture interval into a series of spectral terms by performing a transformation from a time domain into a transformed domain;
evaluate the series of spectral terms in the transformed domain to identify one or more spectral terms associated with the narrowband interference signals from the narrowband interference source, wherein the identified spectral terms are unrelated to the message from the limited energy body implanted device; and
initialize the identified terms associated with the narrowband interference source to a desired value to generate a filtered series of spectral terms.
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Accused Products
Abstract
Communication techniques are described that can improve signal reception from an implanted wireless device to a main control unit (MCU) while in the presence of a narrowband interferer. The implanted wireless device can be any appropriate device such as a microtransponder, microstimulator, a sensor device or a drug delivery device. The MCU captures samples of signals emanating from the wireless device during an expected transmission time interval. The captured samples are evaluated and transformed into a series of spectral terms that are then evaluated to identify narrowband interference signals. The identified narrowband interference terms can be initialized to a null value to remove the signal spectrum resulting from the communication, and an inverse transformation can be used to generate a time domain signal that is free from interference. Overlapping windows and other signal processing techniques can also be applied to improve overall communications.
20 Citations
20 Claims
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1. An external communication system for communicating with a limited energy body implanted wireless device that is substantially shielded from a narrowband interference source, wherein the external communication system is arranged to mitigate effects of narrowband interference signals from the narrowband interference source, the external communication system comprising:
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a receiver that is arranged to capture signals associated with a transmission from the limited energy body implanted device during a capture interval for the receiver, wherein a duration of the capture interval for the receiver is substantially greater than a transmit time associated with the transmission, wherein the captured signals include at least one member of the group consisting of;
a portion of a message from the limited energy body implanted device, narrowband interference signals, and noise signals;a buffer that is arranged to store samples associated with the captured signals; and a signal processor that is arranged to process the stored samples, wherein the signal processor is arranged to; transform the stored samples from at least a portion of the capture interval into a series of spectral terms by performing a transformation from a time domain into a transformed domain; evaluate the series of spectral terms in the transformed domain to identify one or more spectral terms associated with the narrowband interference signals from the narrowband interference source, wherein the identified spectral terms are unrelated to the message from the limited energy body implanted device; and initialize the identified terms associated with the narrowband interference source to a desired value to generate a filtered series of spectral terms. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An external communication system for communicating with multiple limited energy body implanted wireless device that is substantially shielded from a narrowband interference source, wherein the external communication system is arranged to mitigate effects of narrowband interference signals from the narrowband interference source, the external communication system comprising:
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a receiver that is arranged to capture signals associated with a transmission from multiple limited energy body implanted devices during an extended capture interval for the receiver, wherein a duration of the extended capture interval for the receiver is substantially greater than a transmit time associated with the transmission from each of the limited energy body implanted devices, wherein the captured signals include at least one member of the group consisting of;
a portion of a message from each limited energy body implanted device, narrowband interference signals, and noise signals;a buffer that is arranged to store samples associated with the captured signals; and a signal processor that is arranged to process the stored samples, wherein the signal processor is arranged to; transform the stored samples from at least a portion of the capture interval into a series of spectral terms by performing a transformation from a time domain into a transformed domain; evaluate the series of spectral terms in the transformed domain to identify one or more spectral terms associated with the narrowband interference signals from the narrowband interference source, wherein the identified spectral terms are unrelated to the message from the limited energy body implanted device; and initialize the identified terms associated with the narrowband interference source to a desired value to generate a filtered series of spectral terms, whereby the extended capture interval for the receiver is sufficiently long so that a common narrowband interferer can be identified for the multiple limited energy body implanted devices. - View Dependent Claims (17)
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18. A method for a main control unit top process communications from at least one limited energy body implanted wireless device that is substantially shielded from a narrowband interference source, wherein the main control unit is arranged to mitigate effects of narrowband interference signals from the narrowband interference source, the method for the main control unit comprising:
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receiving an RF signal from an antenna; mixing the RF signal with a local oscillator signal to generate a baseband difference signal with a limited frequency bandwidth; sampling the difference signal to generate time domain samples; storing the time domain samples in a capture memory as time domain data; transforming at least a portion of the time domain data from the capture memory into a series of spectral terms by performing a transformation from a time domain into a transformed domain; evaluating the series of spectral terms in the transformed domain to identify one or more spectral terms associated with the narrowband interference signals from the narrowband interference source, wherein the identified spectral terms are unrelated to the message from the limited energy body implanted device; and initializing the identified terms associated with the narrowband interference source to a desired value to generate a filtered series of spectral terms. - View Dependent Claims (19, 20)
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Specification