Abstract
Chaotic communication in Radio-over-Fiber (RoF) system has been demonstrated and numerically investigated. The advantages of this system include efficient use of bandwidth, high-bit rate, long-distance transmission, and security of the wireless communications. The implementation of this chaotic communication system is based on the synchronization two identical lasers, where chaotic carrier is generated with an optoelectronic feedback (OEF) scheme. With different message encoding schemes, including the additive chaotic modulation (ACM) and the on-off shift keying (OOSK), the secured communication in RoF system can be achieved. The performance of chaotic communication system in back-to-back configuration, fiber channel, and radio channel has been investigated respectively. In fiber transmission module, influences of fiber attenuation, nonlinearity, dispersion, and amplifier spontaneous emission (ASE) noise have been taken into accounts. The system bit-error-rate (BER) for different fiber transmission distances and message bit rate is calculated. The effects of the radio channel including path loss, additive white Gaussian noise (AWGN), and multipath are considered. Moreover, the RoF system is achieved after combing the fiber channel with the radio channel. Chaotic communication in RoF system at a bit rate of Gbit/s level is investigated numerically using optoelectronic feedback semiconductor lasers. The OOSK scheme is shown to be more suitable for the RoF system, which it can provide long-distance transmission to above 100 km. On the other hand, the ACM scheme only shows moderate performance in the fiber transmission.