Performance of MU-MIMO WLAN Systems with User Selection and Receive Diversity

Jorge F. Grybosi, Guilherme Luiz Moritz, Glauber Brante, Richard Demo Souza

DOI: 10.14209/SBRT.2020.1570648759

Evento: XXXVIII Simpósio Brasileiro de Telecomunicações e Processamento de Sinais (SBrT2020)

Keywords:

Abstract

Multi-User (MU) MIMO schemes introduced to IEEE 802.11ac amendments can achieve high throughput by transmitting different data streams to multiple users simultaneously. However, it requires the user Channel State Information (CSI), which is not trivial to obtain in practice. Alternatively, the access point can balance the expected rate with the CSI processing overhead by choosing an appropriate number of transmitting and receiving antennas, as well as the number of users according to client channel and backlog. We propose the application of a user selection algorithm based on MU-MIMO theoretical properties and user omnidirectional SNR named PUMA (Pre-sounding User and Mode selection Algorithm) and its application on a diversity scenario. We compare the data rate of the proposed scheme with traditional fixed-mode and exhaustive search user selection, and the equivalent effects on energy efficiency. Results show that the PUMA advantages are enhanced in a diversity scenario when client grouping causes dramatic changes in the sum rate. Besides, by using different diversity schemes on the same WLAN configuration, we obtained different rates and consumption.

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