Effect of atmospheric turbulence on the bit error probability of a space to ground near infrared laser communications link using binary pulse position modulation and an avalanche photodiode detector
Abstract
The effect of atmospheric turbulence on the bit error rate of a spacetoground near infrared laser communications link is investigated, for a link using binary pulse position modulation and an avalanche photodiode detector. Formulas are presented for the mean and variance of the bit error rate as a function of signal strength. Because these formulas require numerical integration, they are of limited practical use. Approximate formulas are derived which are easy to compute and sufficiently accurate for system feasibility studies, as shown by numerical comparison with the exact formulas. A very simple formula is derived for the bit error rate as a function of signal strength, which requires only the evaluation of an error function. It is shown by numerical calculations that, for realistic values of the system parameters, the increase in the bit error rate due to turbulence does not exceed about thirty percent for signal strengths of four hundred photons per bit or less. The increase in signal strength required to maintain an error rate of one in 10 million is about one or two tenths of a db.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 August 1987
 Bibcode:
 1987STIN...8821189S
 Keywords:

 Atmospheric Turbulence;
 Avalanche Diodes;
 Bit Error Rate;
 Infrared Lasers;
 Near Infrared Radiation;
 Optical Communication;
 Pulse Position Modulation;
 Satellite Communication;
 Digital Systems;
 Feasibility Analysis;
 Signal Processing;
 Space Communications, Spacecraft Communications, Command and Tracking