FPGA-Based Real-Time Implementation and Experimental Validation of an FM-ASK Chaotic Communication Scheme

Chaotic waveforms provide a deterministic and noise-like means of masking information in wireless communication systems. This work presents an FPGA-based implementation and experimental validation of a frequency-modulated amplitude-shift keying (FM-ASK) chaotic communication scheme using a deterministic broadband chaotic waveform generated by a dynamical system of a modernized Anishchenko–Astakhov type. The chaotic generator is derived from a transistor structure with negative differential resistance and implemented on an FPGA using Q16.16 fixed-point arithmetic and non-pipelined Euler numerical integration. The hardware implementation is validated against a high-precision Python model using time-domain waveforms, phase portraits, Poincaré sections, bifurcation diagrams, and Lyapunov characteristics. The resulting chaotic waveform is integrated into a complete radio-frequency transmission and reception chain operating in the 2.3–2.5 GHz frequency range. Experimental measurements confirm the information transmission at data rates of up to 500 kbit/s over distances of up to 1 km at a transmit power of 25 dBm. The system also demonstrates information transmission in the presence of a substantially stronger wideband interference signal. For an interference bandwidth of 157.8 MHz and an experimentally determined receiver bandwidth of up to 100 MHz, the estimated interference-to-signal power ratio is approximately 20.0–24.8 dB for interference powers of 50–150 W, corresponding to an estimated SINR of approximately −20.0 to −24.8 dB when receiver noise is negligible compared with the interference. The obtained results demonstrate the feasibility of implementing deterministic broadband chaotic communication on FPGA hardware and its practical applicability to information transmission even under strong wideband interference conditions.