In this paper

ambient IoT is used as a typical use case of massive connections for the sixth generation (6G) mobile communications where we derive the performance requirements to facilitate the evaluation of technical solutions. A rather complete design of unsourced multiple access is proposed in which two key parts: a compressed sensing module for active user detection

and a sparse interleaver-division multiple access (SIDMA) module are simulated side by side on a same platform at balanced signal to noise ratio (SNR) operating points. With a proper combination of compressed sensing matrix

a convolutional encoder

receiver algorithms

the simulated performance results appear superior to the state-of-the-art benchmark

yet with relatively less complicated processing.