complementary detection scheme 2 diagonal permutation shift 2 multiple access interference 2 optical code division multiple access 2 single photodiode 2 spectral amplitude coding 2 Angular momentum 1 Atmospheric turbulence 1 Bit error rate 1 Bit-error rate 1 Clear air 1 Code division multiple access 1 Codes (symbols) 1 Free space optics 1 Freespace optics 1 Light interference 1 Optical code division multiplexing access 1 Optical communication 1 Orbital angular momentum 1 Propagation range 1 Rain 1 Research & information: general 1 Space division multiplexing 1 Space optics 1 Spectra amplitude coded-optical code division multiplexing access 1 Spectra's 1 Spectral amplitude 1 Spectrum amplitude coded-optical code division multiplexing access 1 Technology: general issues 1