Using DCT-Based Audio Watermark for Indoor Location System

• Main Authors: Pei-shan Kao, 高霈珊
• Other Authors: Hsien-tsung Hsu
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/tjprf8

碩士 === 國立中央大學 === 通訊工程學系 === 102 === With the wide using of Global Positioning System, people more and more rely on positioning and navigation functions. When we want to go to somewhere we have never been to, we would like to have positioning and navigation functions for giving directions. Due to the shadowing effect of the building, GPS signals will be attenuated significantly and positioning results will be affected seriously. How to develop an accurate indoor location system is the goal of many relevant studies in recent years. Most of existing indoor location techniques use radio access technologies as the transmission medium, such as the Geometrical Triangulation of using Wi-Fi and iBeacon of using Bluetooth, etc. However, these techniques still exist the problem of location accuracy, as well as the need of providing additional related equipment. As the result, we hope that we can through another kind of medium to achieve accurate indoor location function and it can avoid the extra cost of devices. The most common medium for transmitting message in daily life is the sound. For example, the advertisement audio in the supermarket and the doorbell in the convenient store, etc. These sound are accustomed to be heard. If we can through embed information into these music, we don’t need to provide any additional devices. When users use their smart phones to record the audio, they can easily know their location by extracting the embedded information. The task of indoor location is completed. This thesis proposes a new technique for indoor location system. By audio watermark, we embed the longitude and latitude information into the music. After users receive the audio from their smart phones, and extract it by the application, they can get the current location information and then instantly display on their devices to complete the application of indoor location.