Compressive random access using distance based resource block selection scheme for machine type communications

Abstract

Compressive random access scheme is considered one of promising candidates for future Machine Type Communications. It enables one-shot detection, which means that the preamble, channel estimation, and data detection could be carried out at once to keep signaling overhead low. For one-shot detection, improving the performance in terms of the number of successfully received preambles is necessary. To increase the number of received preambles, the method of dividing the resource block (RB) into multiple RBs has been proposed. However, the existing multiple RB selection method resulted in an excessive size of cyclic prefix (CP) for a large cell. To mitigate this problem, we consider the distance based RB selection scheme in this paper. A critical feature of this scheme is that as RBs are allocated by distance, the length of CP can be reduced. In order to understand the impact of length of CP on the performance, we study the throughput when compressive sensing (CS) based detection is used. Through simulations, we confirm that our distance based RB selection scheme can improve the throughput of compressive random access.