It is well known that MIMO systems offer the promise of achieving very high spectrum efficiencies (many tens of bit/s/Hz) in a mobile environment. The gains in MIMO capacity are sensitive to the presence of spatial and temporal correlation introduced by the radio environment. In this paper we examine how MIMO capacity is influenced by a number of factors e.g. a) temporal correlation b) various ...

Abrlracr-A h u l a for the cppecity et arbitrary sbgle-wer chrurwla without feedback (mot neccgdueily Wium" stable, stationary, etc.) is proved. Capacity ie shown to e i p l the supremum, over all input processts, & the input-outpat infiqjknda QBnd as the llnainl ia praabiutJr d the normalized information density. The key to thir zbllljt is a ntw a"c sppmrh bosed 811 a Ampie II(A Lenar trwrd eu...

Despite much impressive work (e.g. [1], [3], [4], [5], [7]) since the introduction of the Shannon capacity in [8], many natural questions regarding this parameter remain widely open (see [2], [6] for surveys). Let G1 + G2 denote the disjoint union of the graphs G1 and G2. It is easy to see that c(G1 + G2) ≥ c(G1) + c(G2). Shannon [8] conjectured that c(G1 + G2) = c(G1) + c(G2), but this was dis...

The large-inputs asymptotic capacity of a peak and average power limited discrete-time Poisson channel is derived using a new firm (non-asymptotic) lower bound and an asymptotic upper bound. The upper bound is based on the dual expression for channel capacity and the recently introduced notion of capacityachieving input distributions that escape to infinity. The lower bound is based on a lemma ...

A biclique in a graph Γ is a complete bipartite subgraph of Γ. We give bounds for the maximum number of edges in a biclique in terms of the eigenvalues of matrix representations of Γ. These bounds show a strong similarity with Lovász’s bound θ(Γ) for the Shannon capacity of Γ. Motivated by this similarity we investigate bicliques and the bounds in certain product graphs.

Both a theoretical approach and measurements of channel characteristics have been carried out to determine the maximum capacity which can be expected when MIMO techniques are implemented in tunnels, and especially in subway tunnels. The influence of the position of the antennas inside the transmitting and the receiving arrays on the correlation between paths and on the singular values of the tr...

For a broad class of interference-dominated wireless systems including mobile, personal communications, and wireless PBX/LAN networks, we show that a significant increase in system capacity can be achieved by the use of spatial diversity (multiple antennas), and optimum combining. This is explained by the following observation: for independent flat-RayIeigh fading wireless systems with N mutual...

The history of computing is a history of virtualization. Each increase in the number of abstraction layers separating the end user from the hardware makes life easier for the user but harder for the system capacity planner who must understand the relationship between logical and physical configurations to guarantee performance. In this paper we discuss possible architectures for virtual systems...

In this two-part paper, we study three capacity regions for fading broadcast channels and obtain their corresponding optimal resource allocation strategies: the ergodic (Shannon) capacity region, the zerooutage capacity region, and the capacity region with outage. In Part I, we obtained the ergodic capacity region of the fading broadcast channel under di erent spectrum-sharing techniques. In th...

In this paper, a comparative estimate of the channel capacity assigned to each user for frequencydivision multiple-access (FDMA) and direct-sequence code-division multiple-access (DS-CDMA) schemes operating in a Rayleigh fading channel is presented. Then, the achievable channel capacity per user (in the Shannon sense) is estimated in an average sense considering the inherent diversity potential...