Energy Efficient Sparse Code-Aided On-Off Division Multiple Access

In this letter, we propose an uplink sparse code-aided on-off division multiple access (SC-ODMA) system that enhances energy efficiency and error correction capabilities. In this SC-ODMA system, each user is assigned a predetermined codebook containing M sparse codewords, integrating bit-to-sparse-code mapping and spreading. Specifically, the message of each user undergoes polar encoding and sparse code mapping, then is transmitted in a time-hopping manner based on user-specific on-off patterns. A key contribution of this letter is the integration of sparse code mapping with ODMA, significantly improving performance while maintaining energy efficiency. Simulation results indicate that the proposed SC-ODMA system notably improves energy efficiency and significantly reduces the block error rate (BLER) compared to traditional ODMA systems. Furthermore, the proposed scheme maintains competitive energy efficiency across various conditions, including code rates, user loads, and BLER targets, illustrating its robustness and adaptability in dynamic communication environments.