  Received signal strength based radio tomographic imaging is a popular
device-free indoor localization method which reconstructs the spatial loss
field of the environment using measurements from a dense wireless network.
Existing methods solve an associated inverse problem using algebraic or
compressed sensing reconstruction algorithms. We propose an alternative imaging
method that reconstructs spatial field of occupancy using a back-projection
based reconstruction algorithm. The introduced system has the following
advantages over the other imaging based methods: i.) significantly lower
computational complexity such that no floating point multiplication is
required; ii.) each link's measured data is compressed to a single bit,
providing improved scalability; iii.) physically significant and repeatable
parameters. The proposed method is validated using measurement data. Results
show that the proposed method achieves the above advantages without loss of
accuracy compared to the other available methods.
