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Separable convex optimization problems with linear ascending inequality and equality constraints are addressed in this paper. Under an ordering condition on the slopes of the functions at the origin, an algorithm that determines the optimum point in a finite number of steps is described. The optimum value is shown to be monotone with respect to a partial(More)
—Rate-constrained power minimization (PMIN) over a code division multiple-access (CDMA) channel with correlated noise is studied. PMIN is shown to be an instance of a separable convex optimization problem subject to linear ascending constraints. PMIN is further reduced to a dual problem of sum-rate maximization (RMAX). The results highlight the underlying(More)
—The problem of computing sum of sources over a multiple access channel (MAC) is considered. Building on the technique of linear computation coding (LCC) proposed by Nazer and Gastpar [1], we employ the ensemble of nested coset codes to derive a new set of sufficient conditions for computing sum of sources over an arbitrary MAC. The optimality of nested(More)
—The 3-user discrete memoryless interference channel is considered in this paper. We provide a new inner bound (achievable rate region) to the capacity region for this channel. This inner bound is based on a new class of code ensembles based on asymptoti-cally good nested linear codes. This achievable region is strictly superior to the straightforward(More)
— In several multi-terminal communication systems, it has been noted that the average performance of linear code ensemble is better than that of the standard unstructured code ensemble. However, it is well-known that linear code ensembles cannot achieve the point-to-point capacity of an arbitrary discrete memoryless channel. In this paper, we study nested(More)
We consider the problem of developing coding techniques and deriving achievable rate regions for discrete memoryless broadcast channels with 3 receivers (3−DBC). We begin by identifying a novel vector additive 3−DBC for which we characterize an upper bound on the the largest achievable rate region based on unstructured codes, henceforth referred to as(More)
—We derive a new achievable rate region for the problem of communicating over a multiple access channel with states. Our coding technique is based on the ensemble of nested coset codes and the technique of typicality decoding. Exploiting structure in this ensemble, we analyze a more efficient decoding strategy to improve upon the rate region achievable(More)
We propose a new coding technique based on nested coset codes and derive a new achievable rate region for a general three user discrete memoryless broadcast channel (DMBC). We identify an example of a three user binary broadcast channel for which the proposed achievable rate region strictly outperforms that obtained by a natural extension of Marton's [1](More)
We consider the problem of communication over a three user discrete memoryless interference channel (3−IC). The current known coding techniques for communicating over an arbitrary 3−IC are based on message splitting, superposition coding and binning using independent and identically distributed (iid) random codebooks. In this work, we propose a new ensemble(More)
The sum capacity on a symbol-synchronous CDMA system having processing gain N and supporting K power constrained users is achieved by employing at most 2N 1 sequences. Analogously, the minimum received power (energy-per-chip) on the symbol-synchronous CDMA system supporting K users that demand specified data rates is attained by employing at most 2N 1(More)