摘要 |
An RFID reader uses an adaptive filter to mitigate the effects of colored noise in tag reply signals. The adaptive filter may be a linear equalizer, a linear-predictive canceller, or a decision-feedback equalizer. The adaptive filter estimates the colored noise portion of the signal received from the tag and removes the noise estimate from the tag signal. The adaptive filter bases its noise estimate on the difference between a desired signal and a portion of the received signal. The reader uses reader-generated training data, a CW signal, and/or portions of the tag reply signal to adapt the filter. |