Orthogonal Frequency Division Multiple Access (OFDMA) is introduced in the 802.11ax standard system to resolve the relevance of transmission problems by splitting the channel into Resource Units (RU) allocated to Stations (STAs), especially in Uplink (UL) multi-user transmission, but struggles with many STAs due to RU size or bandwidth constraints. Non-Othorgonal Multiple Access (NOMA) is a highly appreciated wireless network technique to overcome these issues. The IDMA can take advantage of NOMA, such as enhancing spectrum efficiency, STA capacity, and data rates without RU size or bandwidth changes. This paper proposes a combination of Interleave Division Multiple Access (IDMA) to massive the number of STAs in UL multi-user into the existing OFDMA system of 802.11ax. Combining the OFDMA and IDMA can reduce the number of STAs per RU, reducing the Multiple Access Interference, which is the problem when using IDMA individually. The results show a significant decrease in Bit Error Rate (BER) quality compared to existing Multiuser-Multiple Input Multiple Output (MU-MIMO), OFDMA, and OFDMA-MU-MIMO in 802.11ax. In addition, OFDMA-IDMA supports a number of STAs 5 times more than OFDMA while maintaining the same quality (BER of approximately 3×10-4at SNR = 20 [dB]).
Massive Up-Link Multi-User with OFDMA-IDMA Combination based on IEEE 802.11ax
2024-06-24
725920 byte
Conference paper
Electronic Resource
English