Besides a “fingerprint locating” technology, which is complex and has poor practicability, a premise of a general existing radio frequency locating technology is that no blocking exists between a radio frequency signal source (an electronic tag) and a radio signal receiver (a reader-writer). In a complex environmental condition, however, various obstacles often exist. Therefore, a large quantity of reader-writers connected to a management computer over a network need to be installed to achieve more precise locating. A complex environment is divided into a plurality of small locating spaces without blocking relatively, or a plurality of locating rings of different sizes, centered around a reader, are arranged (in a Cell-ID locating manner). Considering factors such as the cost, this solution becomes impractical and has low system reliability. Therefore, how to achieve precise locating on a goods and materials device, a person, and the like in a complex environment such as a warehouse, a workshop, an exhibition, and the like site with low a cost becomes a big complication for the radio frequency locating technology.
USPTO Backgrounds
USPTO Backgrounds