ABSTRACT Multi-user transmission at 60 GHz promises to increase the throughput of next generation WLANs via both analog and digital beamforming. To maximize capacity, analog beams need to be jointly configured with user selection and digital weights; however, joint maximization requires prohibitively large training and feedback overhead. In this paper, we scale multi-user 60 GHz WLAN throughput via design of a low-complexity structure for decoupling beam steering and user selection such that analog beam training precedes user selection. We introduce a two-class framework comprising (i) single shot selection of users by minimizing overlap of their idealized beam patterns obtained from analog training and (ii) interference-aware incremental addition of users via sequential training to better predict inter-user interference. We implement a programmable testbed using software defined radios and commercial 60 GHz transceivers and conduct over-the-air measurements to collect channel traces for different indoor WLAN deployments. Using trace based emulations and high resolution 60 GHz channel models, we show that our decoupling structure experiences less than 5% performance loss compared to maximum achievable rates via joint user-beam selection. 
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                            A Detailed Look at MIMO Performance in 60 GHz WLANs
                        
                    
    
            One of the key enhancements in the upcoming 802.11ay standard for 60 GHz WLANs is the support for simultaneous transmissions of up to 8 data streams via SU- and MU-MIMO, which has the potential to enable data rates up to 100 Gbps. However, in spite of the key role MIMO is expected to play in 802.11ay, experimental evaluation of MIMO performance in 60 GHz WLANs has been limited to date, primarily due to lack of hardware supporting MIMO transmissions at millimeter wave frequencies. In this work, we fill this gap by conducting the first large-scale experimental evaluation of SU- and MU-MIMO performance in 60 GHz WLANs. Unlike previous studies, our study involves multiple environments with very different multipath characteristics. We analyze the performance in each environment, identify the factors that affect it, and compare it against the performance of SISO. Further, we seek to identify factors that can guide beam and user selection to limit the (often prohibitive in practice) overhead of exhaustive search. Finally, we propose two heuristics that perform both user and beam selection with low overhead, and show that they perform close to an Oracle solution and outperform previously proposed approaches in both static and mobile scenarios, regardless of the environment and number of users. 
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                            - PAR ID:
- 10343777
- Date Published:
- Journal Name:
- Proceedings of the ACM on Measurement and Analysis of Computing Systems
- Volume:
- 6
- Issue:
- 2
- ISSN:
- 2476-1249
- Page Range / eLocation ID:
- 1 to 26
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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