A New Pulse Modulation Method for Underwater Acoustic Communication Combined with Multiple Pulse Characteristics

In the field of covert communication, chaotic pulse-position modulation (CPPM) and chaotic pulse-width modulation (CPWM) have developed rapidly. Compared with the traditional pulse-position modulation (PPM) and pulse-width modulation (PWM), the chaotic modulation communication is better, but the communication rate is still not improved. Based on the CPPM technology, a new communication system for the underwater acoustic communication is proposed based on the CPWM technology, which combined the chaotic pulse position characteristic and the chaotic pulse width characteristic called chaotic pulse-position and pulse-width combined modulation (CPWCM) communication system. The CPWCM communication system has double concealment, compared with CPPM and CPWM communication system, the combined modulation has better concealment, higher communication rate and greater effective bandwidth. In this paper, the chaotic pulse-position and chaotic pulse-width modulation method are used to study the CPWCM underwater acoustic communication system, which is implemented with the tent mapping. At the end of this paper, the characteristics and BER of the CPWCM underwater acoustic communication system are analyzed. the CPWCM communication system has similar BER level when it transmits the same information with the CPPM communication system. But the CPWCM communication system has double transmission rate, which verifies the validity of the CPWPM underwater acoustic communication system.