Interference detection and mitigation in RFID readers and systems

A method for mitigating radio frequency (RF) interference in and/or outside a band of RFID operation, the method comprising:

• detecting interference in and/or outside a band of RFID operation;
• controlling an aspect of operation of an RFID reader for mitigating the detected interference, wherein controlling the aspect of operation of the RFID reader includes identifying temporal gaps in the interference, and causing RFID communications to be performed during the temporal gaps in the interference;
• receiving power directly from a splitter or coupler at a position prior to an RF bandpass filter, the coupler or splitter being positioned in a receive channel of the RFID reader and immediately adjacent to each of, and between, the RF bandpass filter and after an amplifier of the receive channel;
• and
• wherein the receive channel is coupled to a quadrature baseband downconversion section including at least one demodulator, at least one filter, and at least one analog to digital converter.

A Radio Frequency Identification (RFID) reader configured to detect radio frequency (RF) interference in and/or outside a band of RFID operation, the RFID reader comprising:

• a receive channel for receiving incoming RF signals;
• and
• hardware for detecting interference in and/or outside a band of RFID operation;
• wherein the hardware for detecting the interference includes a power detector in the receive channel, and hardware for monitoring an output of the power detector during times when the RFID reader is not transmitting;
• wherein the power detector receives power directly from a coupler or splitter at a position prior to an RF bandpass filter, the coupler or splitter being positioned in the receive channel after an amplifier of the receive channel;
• logic configured to determine whether the detected interference is at least one of pulsed and periodic, and in response to detecting the interference is at least one of pulsed and periodic, to create a schedule of the detected interference and cause the RFID reader to perform RFID communications during interferer-off times based on the schedule;
• hardware for mitigating the detected interference by causing the RFID reader to use only one backscatter sidetone for RFID communication, wherein the sidetone used is on an opposite side of a main carrier than the interference;
• logic configured to alert a user and/or a system that tag read performance is compromised due to interference, wherein a likely source of the interference is indicated;
• logic configured to control an aspect of operation of the RFID reader for mitigating the detected interference, wherein the logic configured to control the aspect of operation of the RFID reader for mitigating the detected interference includes logic selected from:
• logic for identifying temporal gaps in the interference, and for causing RFID communications to be performed during the gaps;
• logic for causing the RFID reader to instruct an RFID tag to change to a low sensitivity mode thereof;
• and
• logic for causing a backscatter link frequency to move away from a frequency of interference;
• and
• wherein the hardware for detecting the interference includes one or more analog to digital converters configured to output a digital sample stream of a received signal, and logic configured to process the sample stream for producing a power spectral density of an RF signal environment;
• and
• wherein the hardware for detecting the interference is further configured to periodically sweep over a predetermined range around a channel of interest and measure changes in signal level.