Feedback communication using orthogonal signals

MMSE Decision Feedback Equalization of Orthogonal Multipulse Modulated Signals

We propose a finite impulse response (FIR) minimum mean squared error (MMSE) decision feedback equalizer (DFE) for orthogonal multipulse modulated signals received through a multipath channel. Our system model accounts for both the loss of orthogonality caused by the multipath channel as well as intersymbol interference (ISI). First, we review previous work on the subject which used the zero-fo...

Multicarrier orthogonal CDMA signals for quasi-synchronous communication systems

We propose a multi-carrier orthogonal CDMA signaling scheme for a multiple-access communication system, such as the reverse channel of a cellular network, as an alternative to the multiuser interference cancellation approach. The average variance of cross-correlations between sequences is used as a measure for sequence design. We search for sets of sequences that minimize the probability of sym...

Feedback control for communication with non-orthogonal states

Computing Derivatives of Noisy Signals Using Orthogonal Functions Expansions

In many applications noisy signals are measured. These signals has to be filtered and, sometimes, their derivative have to be computed. In this paper a method for filtering the signals and computing the derivatives is presented. This method is based on expansion onto transformed Legender polynomials. Numerical examples demonstrates the efficacy of the method as well as the theoretical estimates.

Free-Space Optical Communication using Orthogonal Optical Angular Momentum Modes

A Multi-channel free-space optical (FSO) communications system based on orbital angular momentum (OAM)-carrying beams is studied. We numerically analyze the effects of atmospheric turbulence on the system and find that turbulence induces attenuation and crosstalk among channels. Based on a model in which the constituent channels are binary symmetric and crosstalk is a Gaussian noise source, we ...