On the Dirty Paper Channel with Fast Fading Dirt

Costa`s "writing on dirty paper" result establishes that full state pre-cancellation can be attained in the Gel`fand-Pinsker problem with additive state and additive white Gaussian noise. This result holds under the assumptions that full channel knowledge is available at both the transmitter and the receiver. In this work we consider the scenario in which the state is multiplied by an ergodic fading process which is not known at the encoder. We study both the case in which the receiver has knowledge of the fading and the case in which it does not: for both models we derive inner and outer bounds to capacity and determine the distance between the two bounds when possible. For the channel without fading knowledge at either the transmitter or the receiver, the gap between inner and outer bounds is finite for a class of fading distributions which includes a number of canonical fading models. In the capacity approaching strategy for this class, the transmitter performs Costa`s pre-coding against the mean value of the fading times the state while the receiver treats the remaining signal as noise. For the case in which only the receiver has knowledge of the fading, we determine a finite gap between inner and outer bounds for two classes of discrete fading distribution. The first class of distributions is the one in which there exists a probability mass larger than one half while the second class is the one in which the fading is uniformly distributed over values that are exponentially spaced apart. Unfortunately, the capacity in the case of a continuous fading distribution remains very hard to characterize

Vector perturbation technique

La “vector perturbation technique” è una tecnica di codifica che permette di avvicinarsi alla capacità teorica del canale in un sistema MIMO. Questa tecnica va a operare sul vettore dati da trasmettere e si articola in quattro punti fondamentali: Channel Inversion, Regolarizzazione, Perturbazione e Perturbazione Regolarizzata. Grazie ad essa è possibile ottenere una capacità che cresce linearmente con il numero minimo tra le antenne trasmittenti/riceventi del sistem

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Take A Moment

The poems, essays, and flash pieces in this creative collection, Take A Moment, engage with the promise of being present. We currently live in a time in which so many people simultaneously busy themselves with noise and distractions while also wishing they could step away from it all and experience the world around them

What is Left

The purpose of this project was to create a collection of poetry that examines the self as a muted element in foreign environments. When placed in a foreign culture, our roles as observers are enhanced due to our limited inclusion within the perceptual frame of references of the cultures and people we observe. Ultimately, the foreigner becomes a parallel sub-system of the dominant foreign culture until such time that he or she makes a direct intrusion into that culture. This level of mutability allows the observer access to cultural elements and interactions inaccessible from within the cultural identity. The principle extends well beyond the role of observers in foreign environments. Observers are also placed into alienated relationships with the immediate environment. Despite the ability of medical and celestial sciences to observe the worlds within and beyond our immediate sphere of experience, human beings rarely interact with the cellular and celestial levels of reality on a sensory level. Furthermore, the poet is perpetually muted from the inner workings of the subjective self. Our imaginations create worlds that enter the neural programming of our brains and exist in parallel as junction points in the constantly changing electro-chemical map of our cognition. Drawing from experiences in international travel, alienating silence, childhood fears, and the relationships of people with the galaxy and cellular functions, this poetry attempts to illustrate the connections between the self and the universe beyond human experience using the poetry of Jack Gilbert, Ruth Stone, Stan Rice, James Wright, and Yusef Komunyakaa as models