Method and system for applying an active radio frequency identification (RFID) tag having a first filter to exclude invalid signals and a second filter to perform a validity judgment

A method for communicating with an active radio frequency identification (RFID) tag, comprising:

• a step a:
• uninterruptedly and repeatedly transmitting, by a coordinator, an instruction signal on a first channel for a preset period of time;
• a step b:
• receiving, by an active RFID tag, the instruction signal during a time period of an interception state;
• and
• a step c:
• establishing, by a reader/writer, communication with the active RFID tag on a second channel after the active RFID tag receives the instruction signal on the first channel;
• wherein the step b further comprises a sub-step b1:
• performing, by the active RFID tag, a first filtering for signals received by the active RFID tag on the first channel to exclude invalid signals;
• and
• the step b further comprises sub-step b2:
• performing, by the active RFID tag, a second filtering of a validity judgment on a received signal having experienced first filtering to determine whether the received signal is the instruction signal for the tag based on digital information carried by the signal;
• wherein if no signal has passed through the active RFID tag, the method further comprises:
• no wasting, by the active RFID tag, time to enter a dormant state;
• and no initiating, by the active RFID tag, the second filtering;
• wherein the method further comprises:
• filtering, by the active RFID tag, the received signals based on the RF features;
• and
• performing, by the active RFID tag, the validity judgment based on digital information carried by the received signal, wherein the validity judgment comprises whether an address code of the received signal is correct.

An active radio frequency identification (RFID) tag, wherein, the active RFID tag communicates with a coordinator and a reader/writer, the coordinator is configured to uninterruptedly and repeatedly transmit an instruction signal for a preset time period on a first channel, and the active RFID tag comprises:

• a receiver, configured to receive the instruction signal during a time period of an interception state;
• wherein the reader/writer is configured to establish communication with the active RFID tag on a second channel after the active RFID tag receives the instruction signal on the first channel, and the active RFID tag further comprises:
• a first filtering module, configured to perform a first filtering for signals received by the active RFID tag on the first channel to exclude invalid signals based on RF features;
• and
• a second filtering module, configured to perform a second filtering of a validity judgment on a received signal having experienced first filtering to determine whether the received signal is the instruction signal for the tag based on digital information carried by the received signal;
• wherein if no signal has passed through the first filter module, the active RFID tag wastes no time to enter a dormant state and does not initiate the second filtering to be performed by the second filter module;
• wherein the first filtering module is a hard filtering module, and filters the received signals based on the RF features;
• and
• the second filter module is a soft filter module and configured behind the first filter module, and performs the validity judgment based on digital information carried by the received signal, wherein the validity judgment comprises judging whether an address code of the received signal is correct.