Performance analysis and preliminary experimental verification of a coherent optical receiver for PPM signals in the presence of atmospheric turbulence

We present the performance analysis and experimental verification of a coherent free-space optical communications system in the presence of simulated atmospheric turbulence. Bit Error Rate (BER) performance is analyzed, and laboratory equipment and experimental setup used to carry out these experiments at the Jet Propulsion Laboratory are described. The key components include two lasers operating at 1064 nm wavelength for use with coherent detection, a 16 element (4X4) focal plane detector array, and data acquisition and signal processing assembly needed to sample and collect the data and analyze the results. The detected signals are combined using the least-mean-square (LMS) algorithm. Convergence of the algorithm for experimentally obtained signal tones in the presence of atmospheric turbulence is demonstrated