An Indoor Positioning Technology Based On Acoustic Communication

Along with the rapid development of communication industry and mobile positioning technology, outdoor navigation technology becoming mature, which has given rise to a series of location-based information services industry with a huge market value. With the rapid development of data services and multimedia business, people are increasingly urgent demand for indoor location information awareness, especially in a complex indoor environment, such as airport, exhibition halls, warehouses, supermarkets, underground parking, mine often requires accurate indoor location information, such as to achieve efficient management of space. However, due to the large attenuation of GPS signals within the building, there is no guarantee that effective coverage of interior space. In recent years, the widespread popularity of mobile terminals offer a wide range of market prospects for indoor positioning technology, the research of indoor positioning technology is becoming the current hot spot.It is a pure software-based solution and uses the acoustic communication technique based on mobile platform. Firstly, we analyzes the propagation characteristics of sound waves in the air channel, signal attenuation, multipath and doppler effect, which influence the acoustic communication. So we choose hyperbolic frequency-modulated that strong anti-interference ability, high multipath resolution, and not sensitive to doppler,as signal waveform of the communication system, through the pulse compression technology to identify the signal; In order to be able to achieve the ideal effect in the mobile terminal, we test acoustic frequency response in terminal equipment of mainstream market, and choose suitable for mobile terminal band as communication frequency; According to the characteristics of the mobile terminal signal processing, the sampling signal is used to identify the frame, and combined with matlab to verify.Secondly, we analyzed the traditional TOA and TDOA ranging technology, aiming at the existence of the clock synchronization, sending time uncertainty, receiving time uncertainty problems are seriously affect the positioning accuracy, we propose that bidirectional induction, self record and time sampling strategy, and through theoretical derivation to convert problems into equipment receives time difference of two signals. The simulation results also proved the feasibility of this technology.Finally, on the basis of distance measurement technology research, we put forward of indoor localization based on acoustic communication prototype, using sound waves radio features, on the basis of the prototype, through the formula deduction and demonstrated, design model of induction that is a launch, more improved; For mobile phone development platform of the receiver and the sender to design software, and in the actual laboratory environment, positioning experiment was carried out. Test results show that the design scheme is based on the mobile platform without increasing any hardware, can complete a reliable high precision indoor positioning.