A method and system for tracking an asset in an indoor facility. The method includes receiving, from a first mobile device, an asset tracking tag collision report, the asset tracking tag collision report including a tag identifier of an asset tracking tag associated with an asset; determining a new location of the asset based on the received asset tracking tag collision report; updating an asset location database to indicate the new location of the asset; and, in response to determining the new location of the asset, transmitting an instruction message to a mobile device to cause the mobile device to direct the asset tracking tag to cease broadcasting the wireless signal. The method and system use crowd-sourcing to determine a new location of an asset that has moved in an indoor facility.

Example embodiments relate to radio frequency identification (RFID) readers and methods for anti-collision in multi-tag RFID systems. One embodiment includes a RFID reader. The RFID reader includes an antenna module configured to scan a plurality of tags. Each of the plurality of tags has a unique identifier (UID) and includes information on an object to which the tag is attached. The RFID reader also includes a control module configured to activate the antenna module to identify the plurality of tags and, in response to a collision event, send a select command with a select condition to identify a specific tag.

Embodiments of the present invention are directed to the field of RFID readers and more specifically to the selective operation of those readers. In an embodiment, the present invention is a system that alternates the operation of an RFID reader between a continuous wave (CW) only state and a read state depending on an absence or a presence of an object of interest within a read-zone of the RFID reader.

In an IC tag issuing apparatus including a plurality of row antenna units arranged by facing the IC tags in multiple rows aligned as an IC tag continuous body in each row, respectively, and conducting communication in an electromagnetic induction method with each of the IC tags of the IC tag continuous body by using a plurality of the row antenna units, a plurality of the row antenna units are arranged in a row direction or in a direction along a conveyance direction of the IC tag continuous body, and each of the row antenna units is electromagnetically shielded except the position faced with the IC tags of the IC tag continuous body (by a shield plate and an antenna case).

Various embodiments relate to a method for classifying received radio frequency signals, including: receiving an input signal; matched filtering the input signal to produce a correlation result signal; sampling the correlation result signal at a plurality of half-bit-grids and a plurality of bit-grids to produce a set of modulated phase correlation result samples and a set of non-modulated phase correlation result samples; calculating a minimum of the set of modulated phase correlation result samples; calculating a maximum of the set of non-modulated phase correlation result samples; and classifying the input signal as valid data or collision data based on the minimum and the maximum.

A method and apparatus for detecting a bulk quantity of RFID tags in a presentation area such as a point-of-sale device. Bulk quantity of RFID tags may be detected according to input to the point-of-sale device including through input from a symbolic barcode scanner, a conveyor belt, a weight scale, and/or via an RF antenna driven at a first power level. After the bulk quantity of RFID tags is detected, the RF antenna is driven at a second, higher power level temporarily to increase bulk RFID tag detection accuracy. Fringe tags may be detected by the RF antenna when it is driven at the higher power level that are in the environment but not presented at the point-of-sale device. Fringe tags may be filtered based on RF characterization of the presentation area including driving the RF antenna outside of presentation sessions and/or filtering RFID tags detected across multiple presentation sessions.

An RFID tag inspection method includes the steps of transmitting a measurement signal from a reader/writer simultaneously to a plurality of RFID tags arrayed on a collective base member and configured to process radio signals, receiving response waves from the individual RFID tags in a batch by the reader/writer, and determining, based on strengths and a number of received signals read by the reader/writer, whether or not the individual RFID tags are acceptable. Thus, acceptance/rejection inspection can be performed on the plural RFID tags, which are arrayed on the collective base member, in a batch.

Systems and methods to determine motion parameters of physical objects using radio frequency identification (RFID) tags attached to the objects. In one embodiment, a method implemented in a radio frequency identification (RFID) system includes determining a motion parameter of the RFID tag based on detecting a Doppler frequency shift in a radio frequency signal received from the RFID tag.

A method for interleaving time slots in a multi-antenna system for communication with RFID tags is disclosed. An example is shown for an eight antenna system. A first four antennas arranged side-by-side are sequentially energized to interrogate RFID transponders. A second set of four antennas arranged side-by-side, the first of which is adjacent to the last of the first set of antennas. A four-antenna sequence is performed for the first four antennas and a second four antenna sequence is performed for the second set of antennas. The first and second four antenna sequences are offset by only a marginal amount, sufficient to ensure that a transponder signal received four antennas away from an active antenna is not acknowledged because the receive window for the non-active antenna is delayed.

Disclosed are techniques for wireless communication. In an aspect, a radio frequency identification (RFID) device receives, from an RFID tag, a first backscattered signal, receives, from the RFID tag, a second backscattered signal having a known time offset relative to the first backscattered signal, and performs interference cancellation on the first backscattered signal based on the second backscattered signal.