  Time Reversal (TR) has been proposed as a competitive precoding strategy for
low-complexity wireless devices relying on Ultra-WideBand (UWB) signal
waveforms. However, when TR is applied for multiple access, the signals
received by the multiple users suffer from significant levels of inter-symbol
and inter-user interference, which requires additional processing for
mitigation by each receiving user. In this paper, we present an iterative
Time-Reversal Division Multiple Access (TRDMA) approach that aims to dim the
latter interference levels. The performance of iterative TRDMA is evaluated
experimentally in a reverberation chamber that mimics a rich scattering indoor
wireless propagation environment. The improved efficiency, in terms of the
number of algorithmic iterations, of the proposed approach compared to
conventional TRDMA, is demonstrated. We also consider a mobile user
configuration, where the position of the receiver changes between the channel
estimation and data transmission steps. It is showcased, even for this
experimental setup, that the proposed iterative TRDMA approach is more
efficient than conventional precoding schemes.
