Free-space communication simulation system and its transmission performance based on non-diffracting beam

The non-diffracting beam has smaller central spot than Gaussian beam and zero divergence angle, therefore it has significant prospect of application in freespace optical communication. A free-space optical communication experimental simulation system based on non-diffracting beam is introduced. The system is connected to the computer by serial port. A microprocessor is used for signal modulation and demodulation by adopting dual header-pulse interval modulation. An axicon is employed to generate non-diffraction beam. In the receiving terminal, a PIN photodiode is used to transfer the optical signal to electrical one. The electrical signal is amplified, shaped and demodulated. The data after demodulation are eventually transferred to the computer by serial port. The error rate is calculated by comparing the sending data and receiving data in the computer. The transmission performance of this system is also evaluated. The error rate is less than 610-5 within the maximum transmission distance when the bit rate is 9 600 bps.