Upper and lower bounds are derived on the capacity of free-space optical intensity channel. This channel has a nonnegative input (representing transmitted intensity), which is corrupted by additive white Gaussian noise. To preserve battery for safety reasons, constrained in both its average peak power. For fixed ratio allowed power to power, difference between upper bound tends zero as infinity their one zero. When only an constraint imposed input, infinity, constant

A technique is proposed for the derivation of upper bounds on channel capacity. It based a dual expression capacity where maximization (of mutual information) over distributions input alphabet replaced with minimization average relative entropy) output alphabet. We also propose analysis asymptotic cost-constrained channels. The observation that under fairly mild conditions achieving "escape to infinity." above techniques are applied multiple-antenna flat-fading channels memory realization...

The large-inputs asymptotic capacity of a peak-power and average-power limited discrete-time Poisson channel is derived using new firm (nonasymptotic) lower bound an upper bound. based on the dual expression for notion capacity-achieving input distributions that escape to infinity. entropy conditionally random variable in terms differential its conditional mean.

This paper investigates a channel model describing optical communication based on intensity modulation. It is assumed that the main distortion caused by additive Gaussian noise, however, with noise variance depending current signal strength. Both high-power and low-power asymptotic capacities under simultaneously both peak-power an average-power constraint are derived. The results new firm (nonasymptotic) lower bound upper bound. relies dual expression for capacity notion of...

The memoryless additive inverse Gaussian noise channel model describing communication based on the exchange of chemical molecules in a drifting liquid medium is investigated for situation simultaneously an average-delay and peak-delay constraint. Analytical upper lower bounds its capacity bits per molecule use are presented. These shown to be asymptotically tight, i.e., delay constraints tending infinity with their ratio held constant (or drift velocity fluid infinity), asymptotic derived...

This paper derives upper and lower bounds on the capacity of multiple-input single-output free-space optical intensity channel with signal-independent additive Gaussian noise subject to both an average-intensity a peak-intensity constraint. In limit where signal-to-noise ratio (SNR) tends infinity, asymptotic is specified, while in SNR zero, exact slope given.

Optimal block-codes (in the sense of minimum average error probability, using maximum likelihood decoding) with a small number codewords are investigated for binary asymmetric channel (BAC), including two special cases symmetric (BSC) and Z-channel (ZC), both arbitrary cross-over probabilities. For ZC, optimal code structure an finite blocklength is derived in two, three, four conjectured case five codewords. BSC, three general BAC, best codebooks under assumption threshold decoder The...

This paper studies the capacity of a general multiple-input multiple-output (MIMO) free-space optical intensity channel under per-input-antenna peak-power constraint and total average-power over all input antennas. The focus is on scenario with more transmit than receive In this scenario, different vectors can yield identical distributions at output, when they result in same image vector multiplication by matrix. We first determine most energy-efficient that attain each these vectors. Based...

We derive the fading number of stationary and ergodic (not necessarily Gaussian) single-input multiple-output (SIMO) channels with memory. This is second term, after double-logarithmic high signal-to-noise ratio (SNR) expansion channel capacity. The transmitter receiver are assumed to be cognizant probability law governing but not its realization. It demonstrated that achieved by independent identically distributed (i.i.d.) circularly symmetric inputs squared magnitude whose logarithm...

The fading number of a general (not necessarily Gaussian) regular multiple-input multiple-output (MIMO) channel with arbitrary temporal and spatial memory is derived. assumed to be noncoherent, i.e., neither receiver nor transmitter have knowledge about the state, but they only know probability law process. second term in asymptotic expansion capacity when signal-to-noise ratio (SNR) tends infinity. It related border high-SNR region double-logarithmic growth.

This paper provides several asymptotic capacity results for the multiple-input multiple-output free-space optical intensity channel in regime of high signal-to-noise ratio (SNR). For case where matrix has full column rank, is derived assuming a peak-power constraint on each transmit antenna, or an average-power total power across all antennas, both. and single-output channels, high-SNR when either only average constrained, per-antenna peak both but with being sufficiently loose.

Optimized shotcrete application techniques are required in particular tunneling projects. Today, any spraying can be done by hand or manipulator. With the development material technologies, range of possible operation was enlarged. automation application, an important contribution to improve performance and quality reduce rebound may achieved. At Swiss Federal Institute Technology, Zurich, systematic research is develop fully automated process control, focusing on wet method. robot, user...

New upper and lower bounds are presented on the capacity of free-space optical intensity channel. This channel is characterized by inputs that nonnegative (representing transmitted intensity) outputs corrupted additive white Gaussian noise (because in free space disturbances arise from many independent sources). Due to battery safety reasons simultaneously constrained both their average peak power. For a fixed ratio power difference between tends zero as infinity, one zero. The case where...

This paper investigates fundamental properties of nonlinear binary codes by looking at the codebook matrix not row-wise (codewords), but column-wise. The family weak flip is presented and shown to contain many beautiful properties. In particular subfamily fair codes, which goes back Shannon et al. was achieve error exponent with a fixed number codewords M, can be seen as generalization linear an arbitrary codewords. are related Hadamard codes. Based on column-wise approach matrix, r-wise...

A rigorous performance analysis of Fano coding is presented, providing an upper bound on the average codeword length binary and ternary codes for arbitrary discrete memoryless source. The slightly better than Shannon's well-known Shannon coding. As a by-product novel general lower entropy derived that might be interest also in different context. This expressed with help variational distance provides special case reverse Pinsker inequality.

In this paper closed-form expressions are derived for the expectation of logarithm and n-th power reciprocal value (inverse moments) a noncentral chi-square random variable even degree freedom. It is shown that these expectations can be expressed by family continuous functions g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> (middot) families have nice properties (monotonicity, convexity, etc.). Moreover, some tight upper lower bounds...

This paper derives the asymptotic capacity for multiple-input single-output free-space optical intensity channel in regime of high signal-to-noise ratio (SNR). The result is proven via upper and lower bounds on at finite SNR.

The non-central chi-square distribution plays an important role in communications, for example the analysis of mobile and wireless communication systems. It not only includes cases a squared Rayleigh Rice distribution, but also generalizations to sum independent Gaussian random variables identical variance with or without mean, i.e., "squared MIMO Rayleigh" Rice" distribution. In this paper closed-form expressions are derived expectation logarithm n-th power reciprocal value variable. is...

A very recent and new model describing communication based on the exchange of chemical molecules in a drifting liquid medium is investigated analytical upper lower bounds capacity are presented. The asymptotically tight, i.e., if average-delay constraint loosened to infinity or drift velocity tends infinity, corresponding asymptotic capacities derived precisely.

In this paper, we re-introduce from our previous work [1] a new family of nonlinear codes, called weak flip and show that its subfamily fair codes belongs to the class equidistant satisfying any two distinct codewords have identical Hamming distance. It is then noted are related binary Hadamard as both code families maximize minimum distance meet Plotkin upper bound under certain blocklengths. Although largest achieve bound, find these by no means optimal in sense average error probability...