Joint user activity and data detection for grant-free non-orthogonal multiple access

Energy Harvesting is one of promising technique to solve the power limitation problem which becomes an important problem for next generation communication. Since the scheduling process of current communication systems causes heavy power consumption in serving a large number of devices, the grant-free communication becomes a viable option in machine-type communication with energy harvesting. In this paper, we propose a joint active user detection (AUD) and data detection technique for grant-free communication systems. In the proposed algorithm, once an active device is identified, the data from this device is detected for the decoding process. We show that the proposed algorithm achieves substantial performance gain over the conventional AUD in realistic uplink grant-free environments.