Uplink and Downlink Precoding for Ultra High Reliability WLAN

IEEE recently started to work on a new WLAN generation under the label ultra-high reliability (UHR). While Wi-Fi 7 focused on higher throughput, UHR aims for more reliable transmission. On the physical layer, this translates into rate-vs-range and latency improvements. Optimized multiuser (MU)-MIMO transmission is important to achieve these improvements. This paper proposes a new precoding method for uplink and downlink MU-MIMO, iterative phase optimization (IPO), and evaluates the performance in terms of rate-vs-range. IPO is shown to give near-optimal performance in typical use cases at a low computational complexity.