3 research outputs found
Spectral radii of asymptotic mappings and the convergence speed of the standard fixed point algorithm
Important problems in wireless networks can often be solved by computing
fixed points of standard or contractive interference mappings, and the
conventional fixed point algorithm is widely used for this purpose. Knowing
that the mapping used in the algorithm is not only standard but also
contractive (or only contractive) is valuable information because we obtain a
guarantee of geometric convergence rate, and the rate is related to a property
of the mapping called modulus of contraction. To date, contractive mappings and
their moduli of contraction have been identified with case-by-case approaches
that can be difficult to generalize. To address this limitation of existing
approaches, we show in this study that the spectral radii of asymptotic
mappings can be used to identify an important subclass of contractive mappings
and also to estimate their moduli of contraction. In addition, if the fixed
point algorithm is applied to compute fixed points of positive concave
mappings, we show that the spectral radii of asymptotic mappings provide us
with simple lower bounds for the estimation error of the iterates. An immediate
application of this result proves that a known algorithm for load estimation in
wireless networks becomes slower with increasing traffic.Comment: Paper accepted for presentation at ICASSP 201