Patent ID: 7860476

Claim:
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.