In this paper, a practical chaos-based modulation scheme is proposed for data broadcasting in the intelligent transportation system (ITS). The data to be broadcasted is modulated into the chaos system by modifying the chaotic parameter. The transmitted chaotic signal has broadband performance. Based on the ergodicity of the chaotic signal, a simple chaotic parameter estimation method is used to estimate the parameter values and then to demodulate the information by a non-coherent demodulator. The proposed chaotic communication scheme called BPSK ergodic chaotic parameter modulation (BPSK-ECPM) reduces the complexity of the synchronization process of spread spectrum transmission and has a strong tolerance of the synchronization error. It is applicable for the real-time vehicle-to-vehicle and road-to-vehicle data broadcasting in ITS. It can be built by simple hardware with low manufacturing cost, which is one of the major considerations in the data broadcast systems.0-7803-7467-3/02/$17.00 ©2002 IEEE.