A SAW-based high-speed spread-spectrum WLAN using chirp π/4-DQPSK modulation

A high data-rate wideband chirp spread spectrum system for indoor communication is implemented. The use of chirp signals with the well known pulse compression technique makes the system extremely robust and therefore suitable for applications in industrial environment. By using π/4-DQPSK modulation and overlapping chirp signals we get data rates up to 70 Mbps. There is no need for sophisticated digital signal processing due to the use of surface acoustic wave (SAW) filters for the generation and filtering of the chirp signals. Production tolerances, temperature drift, and other system imperfections are shown to be either negligible or can easily be tracked. Simulation results reveal that the limiting factor for the data rate is intersymbol interference caused by multipath propagation. A simple hardware demonstrator validates the simulation results