Broadband Communications, Networks, and Systems. 7th International ICST Conference, BROADNETS 2010, Athens, Greece, October 25–27, 2010, Revised Selected Papers

Research Article

Practical Multi-antenna Spatial Reuse in WLANs

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  • @INPROCEEDINGS{10.1007/978-3-642-30376-0_11,
        author={Sriram Lakshmanan and Karthik Sundaresan and Mohammad Khojastepour and Sampath Rangarajan},
        title={Practical Multi-antenna Spatial Reuse in WLANs},
        proceedings={Broadband Communications, Networks, and Systems. 7th International ICST Conference, BROADNETS 2010, Athens, Greece, October 25--27, 2010, Revised Selected Papers},
        keywords={smart antennas spatial reuse interference suppression},
  • Sriram Lakshmanan
    Karthik Sundaresan
    Mohammad Khojastepour
    Sampath Rangarajan
    Year: 2012
    Practical Multi-antenna Spatial Reuse in WLANs
    DOI: 10.1007/978-3-642-30376-0_11
Sriram Lakshmanan1, Karthik Sundaresan2, Mohammad Khojastepour2, Sampath Rangarajan2
  • 1: Georgia Institute of Technology
  • 2: NEC Laboratories America Inc.


Smart antennas can improve spatial reuse in a wireless network through interference suppression. However, interference suppression requires support from clients in the form of channel estimation, which existing clients do not support. In this work, we explore practical solutions to obtain spatial reuse with smart antennas without requiring hardware changes to clients. To this end, we design a novel solution for improving spatial reuse in indoor WLANs which uses ‘approximate’ channel estimates and still yields close to ideal performance. Our solution called Light-weight Multi-Antenna Spatial Reuse () consists of (i) a multi-link channel estimation scheme that can be realized with simple measurements that existing WLAN clients provide readily, (ii) a low-complexity scheduler to decide the subset of beamformed links that must be active concurrently. We demonstrate that the estimates obtained using this scheme when used with a multi-link beamforming technique such as Zero Forcing yields significant interference suppression benefits. We implement the channel estimation scheme on a testbed of software radio clients to demonstrate its practical feasibility. Further, we evaluate the performance of using extensive signal strength traces from 802.11g Access Points equipped with eight element antenna arrays in an indoor office environment. The results indicate that achieves close to the performance obtained with an optimal scheme that uses accurate channel estimates and also improves the median sum rate of indoor users by up to 2.7x over competing approaches.