We derive the capacity region for a broadcast channel with intersymbol interference (ISI) and colored Gaussian noise under an input power constraint. The region is obtained by first defining a similar channel model, the circular broadcast channel, which can be decomposed into a set of parallel degraded broadcast channels. The capacity region for parallel degraded broadcast channels is known. We...

In this paper, a class of state-dependent relay channel with orthogonal channels from the source to the relay and from the source and the relay to the destination is studied. The two orthogonal channels are corrupted by two independent channel states SR and SD, respectively, which are known to both the source and the relay. The lower bounds on the capacity are established for the channel either...

This paper studies the Gaussian wiretap channel with correlated sources available not only at the transmitter and legitimate receiver, but also the eavesdropper. In particular, we are interested in the open problem of finding the optimal auxiliary random variable, which provides a closed-form solution to the secret-message and secret-key capacity region. To do that, we first take a deterministi...

We consider a network of n sender/receiver pairs, placed randomly in a region of unit area. Network capacity, or maximum throughput, is defined as the highest rate that can be achieved by each sender/receiver pair over a long time. It is known that without using relays (i.e., via only direct communication), the maximum throughput is less than O(1), that is, it strictly decays as n increases. Th...

Communication over a multiple access channel is considered. Each user modulates his signal as a superposition of redundant data streams where interconnection of data bits can be represented by means of a sparse graph. The receiver observes a signal resulting from the coupling of the sparse modulation graphs. Iterative interference cancellation decoding is analyzed. It is proved that spatial gra...

Information capacity is determined for a Gaussian communication channel when the constraint is given in terms of a covariance which is different from that of the channel noise. AMS (M)S) subject classifications (1970): Primary, 94A15, 60G35

This paper studies the capacity of the peak-and-average-power-limited Gaussian channel when its output is quantized using a dithered uniform quantizer of step size ∆. It is shown that the capacity of this channel tends to that of the unquantized Gaussian channel when ∆ tends to zero, and it tends to zero when ∆ tends to infinity. In the low signal-to-noise ratio (SNR) regime, it is shown that, ...

We consider a linear Gaussian noise channel used with delayed feedback. The channel noise is assumed to be an ARMA (autoregressive and/or moving average) process. We reformulate the Gaussian noise channel into an intersymbol interference channel with white noise, and show that the delayed-feedback of the original channel is equivalent to the instantaneous-feedback of the derived channel. By gen...

In this work we study the secrecy capacity of Gaussian multiple-input multiple-output (MIMO) wiretap channels (WTCs) with a finite memory, subject to a per-symbol average power constraint on the MIMO channel input. MIMO channels with finite memory are very common in wireless communications as well as in wireline communications (e.g., in communications over power lines). To derive the secrecy ca...

In this thesis we investigate the capacity of multi-user wireless communication channels. We first establish a duality relationship between the Gaussian broadcast and multiple-access channels. This relationship allows us to characterize the capacity region of the Gaussian broadcast channel in terms of the dual Gaussian multiple-access channel, and vice versa. This relationship holds for constan...