The stochastic processes of almost exclusive interest in modeling channel noise are the Gaussian processes. Gaussian processes are stochastic processes for which the random variables N(t1), N(t2), . . . , N(tk) are jointly Gaussian for all t1, . . . , tk and all k > 0. Today we start by giving a more complete discussion of jointly Gaussian random variables. We restrict our attention to zero mea...

Sets of unit vectors in N-dimensional Eucl idean vectorspace whose constituent vectors are separated one from another by atleast a fixed distance d, prescr ibed once for all and independent of N,are of interest in theory and practice; they have fondly been called“porcupine codes.” Although an elegant constructive proof of Gilbertshows that the number of vectors in a porcupin...