A new M-ary/SSMA scheme applicable in LEO satellite communication systems
Tadahiro Wada, Takaya Yamazato, Masaaki Katayama, Atsunori Ogawa · 2002
We discuss non-coherent reception of M-ary spread-spectrum multiple-access (M-ary/SSMA) signals in the presence of large Doppler frequency shift. The Hadamard codes (H-codes) are applied as orthogonal codes. The influence of the Doppler frequency shift has a particular characteristic according to the property of the H-codes. Making use of this property, we first propose an initial carrier frequency acquisition method which can estimate the value of large Doppler frequency shift. We then proposed a M-ary/SSMA scheme that is based on the simultaneous transmission of two distinctive H-codes.