  In this paper, we explore an efficient uncoupled unsourced random access
(UURA) scheme for 6G massive communication. UURA is a typical framework of
unsourced random access that addresses the problems of codeword detection and
message stitching, without the use of check bits. Firstly, we establish a
framework for UURA, allowing for immediate decoding of sub-messages upon
arrival. Thus, the processing delay is effectively reduced due to the
decreasing waiting time. Next, we propose an integrated decoding algorithm for
sub-messages by leveraging matrix information geometry (MIG) theory.
Specifically, MIG is applied to measure the feature similarities of codewords
belonging to the same user equipment, and thus sub-message can be stitched once
it is received. This enables the timely recovery of a portion of the original
message by simultaneously detecting and stitching codewords within the current
sub-slot. Furthermore, we analyze the performance of the proposed integrated
decoding-based UURA scheme in terms of computational complexity and convergence
rate. Finally, we present extensive simulation results to validate the
effectiveness of the proposed scheme in 6G wireless networks.
