We show how to use properties of the quantum conditional mutual information to obtain continuity bounds for information characteristics of quantum channels depending on their input dimension. First we prove tight estimates for variation of the output Holevo quantity with respect to simultaneous variations of a channel and of an input ensemble. Then we obtain tight continuity bounds for output c...

A new concept, the Bit-Mixer is introduced. It is a function of fixed, possibly different size of input and output, which computes statistically uncorrelated output from correlated input values, and its behavior is altered by parameters, called keys. Several constructions are presented, with very fast, power efficient implementations in electronic hardware, having very little side channel leaka...

A least squares smoothing (LSS) approach is presented for the blind estimation of single-input multiple-output (SIMO) finite impulse response systems. By exploiting the isomorphic relation between the input and output subspaces, this geometrical approach identifies the channel from a specially formed least squares smoothing error of the channel output. LSS has the finite sample convergence prop...

Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing (MIMO-OFDM) systems play a vital role in the channel estimation. The wireless channel suffers from impairments like fading and interference. Technologies that achieved above requirements are Multiple Input Multiple Output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM). Channel impairments must be mitigated a...

We consider a good code for a discrete memoryless source with a specified distortion level to be one whose rate is close to the corresponding rate-distortion function and which, with large probability, reproduces the source within the allowed distortion level. We show that any good code must contain an exponentially large set of codewords, of effectively the same rate, which are all typical wit...

The routing capability is a requisite in quantum network. Although the quantum routing of signals has been investigated in various systems both in theory and experiment, the general form of quantum routing with many output terminals still needs to be explored. Here we propose a scheme to achieve the multi-channel quantum routing of the single photons in a waveguide-emitter system. The channels ...