Performance Comparison of Loading Algorithms for 80 MHz IEEE 802.11 WLANs

Wireless local area networks are known to apply the same transmit power and modulation type over all employed OFDM subcarriers. Recent studies show that this can lead to significant performance degradations. As future WLANs will employ even larger bandwidths (80 MHz and above) we study in this paper loading strategies to improve the system performance. In particular, we study the performance of adaptive modulation, power loading and bit loading not only from the physical layer point of view but also by accounting for necessary protocol extensions to accommodate the required control overhead. Our studies reveal that, indeed, loading algorithms can provide significant performance improvements especially for 80 MHz systems. However, the selection of the most appropriate approach depends on channel, protocol and traffic parameters. Hence, this choice is not straightforward and has a substantial impact on the overall system's performance.