Simple radio positioning system based on direct sequence spread spectrum

This paper proposes a simple positioning method for small devices based on direct sequence spread spectrum signal. The proposed scheme measures the sign of inner product between reference signal from a loop antenna and the delayed signal from the double loop antenna. Thus, it can identify the region where the receiver exists based on the inner product. Numerical results show that the area where the inner product becomes negative or positive is symmetric with respect to the position of the transmitter and the inner product can be useful to detect the region where the receiver belongs.