Patent ID: 9264151
Filing Date: 2016-02-16
CPC Classification: G01S,G06K,G06Q,H04B,H04L,H04W

Claim Text:
1. A system, comprising: a signal generator configured to generate an ultrasonic signal that includes a plurality of selected frequencies that are selected from among a set of candidate frequencies, wherein information is encoded on the ultrasonic signal based on which of the candidate frequencies are selected to be included in the ultrasonic signal, wherein the encoded information comprises a store identifier identifying a retail store and a signal for Doppler correction, and wherein the ultrasonic signal comprises at least one frequency in the range of 19 KHz to 22 KHz; and a transmitter configured to transmit the ultrasonic signal within the retail store; wherein presence of a device in the retail store is determined in response to reception of the ultrasonic signal at the device and extraction of the store identifier from the received ultrasonic signal by decoding the ultrasonic signal and compensating for Doppler shift introduced by motion of the device in the retail store using the signal for Doppler correction.