Özateş, MertKazemi, MohammadDuman, Tolga Mete2024-03-212024-03-212023-08-301536-1276https://hdl.handle.net/11693/115046We consider unsourced random access over fading channels with a massive number of antennas at the base station, and propose a simple, yet energy-efficient solution by dividing the transmission frame into slots. We utilize non-orthogonal pilot sequences followed by a polar codeword for transmission in each slot. At the receiver side, we first detect the transmitted pilot sequences by employing a generalized orthogonal matching pursuit algorithm and utilize a linear minimum mean square error solution to estimate the channel vectors. We then perform an iterative decoding based on maximal ratio combining, single-user polar decoding, and successive interference cancellation with re-estimation of the channel vectors to recover the data bits. We also analyze the performance of the proposed scheme using normal approximations and provide a detailed complexity analysis. Numerical examples demonstrate that the proposed scheme either outperforms the existing schemes in the literature or has a competitive performance with a lower complexity. Furthermore, it is suitable for fast-fading scenarios due to its excellent performance in the short blocklength regime.en-USCCBY-NC-ND 4.0 DEED (Attribution-NonCommercial-NoDerivs 4.0 International)https://creativecommons.org/licenses/by-nc-nd/4.0/Unsourced random accessMassive MIMOPolar codesGeneralized orthogonal matching pursuitArticle10.1109/TWC.2023.33082181558-2248