Mass Reversal and Space-Time Inversions

Time-Reversal Space Division Multiple Access over Multi-path Channels

A novel concept of time-reversal division multiple access (TRDMA) is proposed in [1] as a low-complexity, energy-efficient wireless multi-user access method. In this paper, we first generalize the work in [1] as a pre-filtering based space division multiple access (SDMA) communication system, where each user’s signature waveform is derived from the information of CIRs between basestation (BS) a...

Metric Space Inversions, Quasihyperbolic Distance, and Uniform Spaces

We define a notion of inversion valid in the general metric space setting. We establish several basic facts concerning inversions; e.g., they are quasimöbius homeomorphisms and quasihyperbolically bilipschitz. In a certain sense, inversion is dual to sphericalization. We demonstrate that both inversion and sphericalization preserve local quasiconvexity and annular quasiconvexity as well as unif...

Time reversal space time block coding with channel estimation and synchronisation errors

time reversal (TR) space time block coding (STBC) is a novel time domain block coding approach developed to mitigate inter-symbol interference (ISI) in dispersive fading channels. This paper discusses a particular implementation of TR-STBC and investigates the effect of both synchronisation errors and channel estimation accuracy on overall system bit error rate. This has particular relevance to...

On time-reversal and space-time harmonic processes for Markovian quantum channels

The time reversal of a completely-positive, nonequilibrium discrete-time quantum Markov evolution is derived via a suitable adjointness relation. Space-time harmonic processes are introduced for the forward and reverse-time transition mechanisms, and their role for relative entropy dynamics is discussed.

Time - Reversal And