ABSTRACT Many communications systems employ training, i.e., the transmission of known signals, so that the channel parameters may be learned at the receiver. This has a dual effect: too little training and the channel is improperly learned, too much training and there is no time left for data transmission before the channel changes. In this paper we use an information-theoretic approach to find...

In this paper, we have analyzed the channel capacity by using the maximal-ratio combing (MRC) diversity scheme for communication systems operating over a composite fading environment modeled by the Generalized-K distribution at the receiver. For the Generalized-K fading channel with arbitrary values for small and large scale fading parameters, we have derived a closed-form expression for the mo...

The combination of demand uncertainty and a lead time for adding capacity creates the risk of capacity shortage during the lead time. We formulate a model of capacity expansion for uncertain exponential demand growth and deterministic expansion lead times when there is an obligation to provide a specified level of service. The service level, defined in terms of the ratio of expected lead time s...

Two design parameters, SNR and correlation, are key factors for enhancing channel capacity in MIMO systems. Achieving high SNR and low correlation is desirable in antenna design. This paper discusses the relation between channel capacity and these two parameters, and presents simple formulas of this relation for propagation channels and antenna coupling of mobile terminals. According to these g...

Cooperative transmission is an emerging communication technology that takes advantage of the broadcast nature of wireless channels. In cooperative transmission, the use of relays can create a virtual antenna array so that multiple-input/multiple-output (MIMO) techniques can be employed. Most existing work in this area has focused on the situation in which there are a small number of sources and...

In this paper, a detailed theoretical analysis of fading margin in an asynchronous code division multiple access (A-CDMA) system is discussed. Rayleigh and Rician frequency-selective slowly fading channels are considered. Probability distribution and density functions of the probability of error are derived for Rayleigh and Rician fading channels. The fluctuations in the channel capacity are pr...