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The problem of stochastically robust minimum mean square error (MMSE) transceiver design is addressed for multiple-input multiple-output (MIMO) point-to-point channels with different imperfect channel state information (CSI) at the receiver and the transmitter. While the receiver has distribution knowledge of the doubly correlated Gaussian channel that is conditioned on pilot-based training observations...
In this work, we are interested in understanding the trade-off between the cost of acquiring accurate information and the improvement in the system performance because of accuracy of information. Specifically, we consider the wireless scheduling scenario where a scheduler residing at the transmitter can acquire the channel state information (CSI) at various levels of accuracy, but at a cost which...
In an underwater environment signal propagation for the acoustic channel is subject to major multipath effect. Therefore, most underwater communication schemes require that the position of the transmitter or receiver is fixed while using directional antennas in order to ensure high signal-to-noise ratio. However, such a requirement hinders node discovery and ad-hoc formation of underwater networks...
A new cross-layer design taking advantage of OFDMA in ad hoc networks is presented. OFDMA technology is exploited at the physical layer to improve data rate through multiuser diversity and to enhance channel throughput by enabling multiple concurrent transmissions over orthogonal subchannels, each consisting of a group of tones or subcarriers. The proposed Subchannel Selection Algorithm (SSA) addresses...
In this paper indoor wireless Infrared (IR) technology for healthcare monitoring is studied. Monitoring provides a continuous and reliable vital sign measurement to secure patient staying in the hospital. Considering that patient moving is inevitable, we focus on a mobile IR channel based on diffuse propagation. A model of mobile channel is developed through the study of statistical distributions...
A land-to-ship (L2S) radio channel measurement mission at 2.075 GHz has been established in Trondheim, Norway, being fully described in this paper. The transmitter (TX) was installed onboard the High Speed Craft (HSC) M/S "Trondheimsfjord I" and the receiver (RX) was located at the building in the harbor. A frequency chirp with 20 MHz bandwidth is emitted by the TX on the moving craft within...
In this paper, we propose a new interference alignment (IA) scheme designing jointly the linear transmitter and receiver for the MIMO interference channel system, using minimum total mean square error criterion, subject to individual transmit power constraints. We show that transmitter and receiver under such criterion could be realized through a joint iterative algorithm. The convergence of the proposed...
Wireless transmission requires the access to a shared medium, so the communication may be susceptible to adversarial eavesdropping. This paper describes how eavesdropping can potentially be limited by resorting to waterfilling-like algorithms by introducing additional constraints. A Gaussian Wire-Tap Channel (WTC) has been considered as the channel in which a transmitter sends confidential messages...
In this paper, dynamic spectrum management is studied for multiple cognitive tactical radio networks coexisting in the same area. A tactical radio network is composed of a transmitter which broadcasts the same information to its multiple receivers. First, we consider the problem of power minimization subject to a minimum rate constraint and a spectral mask constraint for a single tactical radio network...
That the environment of distribution brings in distortion in an ideal signal, radiated a transmitter, both as a result of addition of noises and by distortion of useful signal. Noises of radio channel include base-line noise of ether, parasite radiations of industrial electrical equipment and other extraneous radiations.
Broadcasting live digital TV to a small battery-powered handheld device is very challenging. One of the evolving technologies to provide such services is DVB-H (Digital Video Broadcasting over Handheld). Wireless channels constitute a fast varying environment that is hostile to reliable communications. Adaptive Modulation and Coding (AMC) is one of the most promising mechanisms to cope with the dynamic...
In this paper, we study secure communications over a two-user semi-deterministic broadcast channel, i.e., one of the receivers is connected to the transmitter through a deterministic channel. We consider the case where the deterministic receiver is also the eavesdropper for the other receiver's message. We derive the secrecy capacity region by showing that superposition encoding plus Gel'fand-Pinsker...
Although conventional cryptographic security mechanisms are essential to the overall problem of security, the openness of wireless medium poses both threats and opportunities for securing transmission. Information theoretic security is attracting researchers for its robust nature. In this paper, a Gaussian multiple input multiple output multiple eavesdropper (MIMOME) channel is considered where a...
Training-based channel estimation involves probing of the channel in time, frequency, and space by the transmitter with known signals, and estimation of channel parameters from the output signals at the receiver. Traditional training-based methods, often comprising of maximum likelihood estimators, are known to be optimal under the assumption of rich multipath channels. Numerous measurement campaigns...
In this paper, we investigate the polarization characteristics of the multiple-input multiple-output (MIMO) channels. The cross polarization discrimination (XPD) is found to change over time, while its variation in frequency domain is relatively small. The probability density function (PDF) of the XPD follows a Gaussian distribution. Analysis and measurement results show that the polarization preserves...
In this paper, a SOS-based prefilter-blind equalizer for MIMO-OFDM system which can equalize FIR-MIMO channel at the receiver is proposed. The proposed scheme uses a set of orthogonal prefilters at the transmitter such that the transmitted signal can be colored temporally thereby satisfying the identifiability condition previously proposed by Hua and Tugnait. The scheme is shown to outperform previously...
This paper is on relay beamforming in wireless networks, in which the receiver has perfect information of all channels and each relay knows its own channels. Instead of the commonly used total power constraint on relays and the transmitter, we use a more practical assumption that every node in the network has its own power constraint. A two-step amplify-and-forward protocol with beamforming is used,...
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