Abstract
The use of spread spectrum technique for the location of the transmitter in an indoor environment is described. The core of this system is a small device called data carrier that can be attached or embedded in an object. Radio propagation through indoor channels is very complex because there are many paths with different power which transfer radio waves from transmitter to the receiver. A deterministic analysis of propagation mechanisms in such an environment is used. The analysis uses 1) the method of moments to approximate the currents induced on the wires by the incident field, and 2) Fourier transform techniques to describe the signal in both the space and the frequency domains, in order to obtain an expression relating the transfer function between transmitter and receiver antennas. Numerical results for a wide range of location are obtained through analytical calculation of the correlation function combined with the computational electromagnetics approach. The factors which influence the type of PN code positioning are discussed, and the performance of this system is presented for various configurations.
