This paper investigates the low earth orbit (LEO) satellite-enabled coded compressed sensing (CCS) unsourced random access (URA) in orthogonal frequency division multiple access (OFDMA) framework

where a massive uniform planar array (UPA) is equipped on the satellite. In LEO satellite communications

unavoidable timing and frequency offsets cause phase shifts in the transmitted signals

substantially diminishing the decoding performance of current terrestrial CCS URA receiver. To cope with this issue

we expand the inner codebook with predefined timing and frequency offsets and formulate the inner decoding as a tractable compressed sensing (CS) problem. Additionally

we leverage the inherent sparsity of the UPA-equipped LEO satellite angular domain channels

thereby enabling the outer decoder to support more active devices. Furthermore

the outputs of the outer decoder are used to reduce the search space of the inner decoder

which cuts down the computational complexity and accelerates the convergence of the inner decoding. Simulation results verify the effectiveness of the proposed scheme.