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In this paper, the source and relay transmit covariance matrices are jointly optimized for a fading multiple antenna relay channel when the transmitters only have partial channel state information (CSI) in the form of covariance feedback. For full-duplex transmission, we evaluate lower and upper bounds on the ergodic channel capacity. These bounds require a joint optimization over the source and relay...
In this paper, we develop a novel joint transmit and receive design for multiuser MIMO (MU-MIMO) systems. The proposed scheme exploits the channel temporal correlation and incorporates the matched filter (MF) combining vector into the beamforming design. Considering the beamforming is optimized with the outdated channel state information (CSI) feedback, we design the beamformer by maximizing the conditional...
Until recently, link adaptation and resource allocation for communication system relied extensively on the spectral efficiency as an optimization criterion. With the emergence of the energy efficiency (EE) as a key system design criterion, resource allocation based on EE is becoming of great interest. In this paper, we propose an optimal EE-based resource allocation method for the scalar broadcast...
Optimizing energy efficiency (EE) for the MIMO broadcasting channels (BC) is considered in this paper, where a practical power model is taken into account. Although the EE of the MIMO BC is non-concave, we reformulate it as a quasiconcave function based on the uplink-downlink duality. After that, an energy efficient iterative waterfilling scheme is proposed based on the block-coordinate ascent algorithm...
We consider rate splitting and interference cancelation in Device-to-Device (D2D) communications underlaying a cellular network. We assume that a transmitted message is split into a private and a public part, as in Han-Kobayashi scheme. The private part is decodable only by the intended receiver, whereas the public part is in addition decodable by an interference victim. The receivers run a best-effort...
A multi-pair two-way relaying scenario with multi-antenna mobile stations is considered. The bidirectional communications between the mobile stations are supported by an intermediate non-regenerative multi-antenna relay station. It is assumed that the mobile stations can subtract the back-propagated self-interference. Different relay transceive filter design approaches which utilize the fact that...
We address joint design of robust precoder and equalizer in a MIMO communication system using the minimization of weighted sum of mean square errors. In addition to imperfect knowledge of channel state information, we also account for inaccurate awareness of interference plus noise covariance matrix and power shaping matrix. We follow the worst-case model for imperfect knowledge of these matrices...
In this paper, we consider the resource allocation problem in the uplink transmission of an orthogonal frequency-division multiple access (OFDMA) based cognitive radio (CR) network. The resource allocation aims to maximize the uplink throughput of secondary users (SUs) in CR network under the constraints of the primary user (PU) interference and the transmit power limits of SUs. In general, the optimal...
This paper considers opportunistic spectrum access for secondary users (SUs) from an adaptive learning perspective. A SU dynamically hops over multiple idle frequency-slots of a licensed frequency band, each with an adaptive activity factor. Aiming to determine the optimal activity factors of SUs, an algorithm is developed, in which each SU independently adjusts its activity factors by learning other...
This paper is concerned with the maximization of the weighted sum-rate in the multicell MIMO multiple access channel (MAC). Considered is the multicell network operating on the same frequency channel with multiple mobile stations (MS) per cell. Assuming the interference coordination mode in the multicell network, each base-station (BS) only decodes the signals for the MSs within its cell. However,...
This paper considers the resource allocation problem for a Multiple Access Relay Channel (MARC). A transmission scheme with OFDMA and Amplify-and-Forward (AF) relaying is assumed. To maximise the sum rate a joint allocation of transmit power and subcarriers has to be done. This problem is known to be NP-hard and can only be solved by an exhaustive search which is not feasible for practical problem...
We considers the beamforming assisted multiple-antenna receiver for space-division multiple-access based multiuser systems that employ high-throughput quadrature amplitude modulation (QAM) signalling. The bit error ratio (BER) expression as the function of the beamformer's weight vector is derived, and the minimum BER (MBER) beamforming receiver is then obtained as the solution of the resulting optimisation...
In this paper we consider secure transmission for the multiple-input, multiple-output, single-antenna-eavesdropper systems with perfect information of the main channel and only the statistics of the eavesdropper's channel state information known at the transmitter. We adopt the celebrated artificial-noise (AN) assisted beamforming, which was studied by Goel and Negi with the limitation that the AN...
In this paper, spectrum-sensing based resource allocation for a cognitive radio network that contains multiple secondary users (SUs) and a primary user (PU) is investigated. Each SU firstly performs the individual spectrum sensing and forwards the result to a fusion center to make the global decision. If PU is determined absent, then SUs access the primary band with their regular transmit power. Otherwise...
Most nonlinear transceiver designs in amplify-and-forward (AF) multiple-input-multiple-output (MIMO) relay systems assume that instantaneous perfect channel state informations (CSIs) are available. Transceiver design with imperfect CSIs have rarely been addressed. In this paper, we consider an AF MIMO system in which a Tomlinson-Harashima precoder (THP) is used at the source, a linear precoder at...
In this paper, we consider the robust transceiver design with Tomlinson-Harashima precoding (THP) for multi-hop amplify-and-forward (AF) multiple-input multiple-output (MIMO) relaying systems. THP is adopted at the source to mitigate the spatial inter-symbol interference and then a joint Bayesian robust design of THP at source, linear forwarding matrices at relays and linear equalizer at destination...
In this paper, we investigate maximum mutual information design for multi-hop amplify-and-forward (AF) multiple-input multiple-out (MIMO) relaying systems with imperfect channel state information, i.e., Gaussian distributed channel estimation errors. The robust design is formulated as a matrix-variate optimization problem. Exploiting the elegant properties of Majorization theory and matrix-variate...
In transmit beamforming multi-antenna systems, the representative quantized channel direction information (CDI) may become outdated due to the feedback delay. Grassmannian predictive coding (GPC) has been shown as an effective method to overcome this problem. However, the existing GPC algorithm is still of practical concern as the quantization resolution may not be ensured at relatively low feedback...
One of the most attractive research topics about multiple-input multiple-output (MIMO) techniques is interference mitigation with limited feedback. Codebook design based on the vector quantization (VQ) algorithms with less quantization error and computational burden is the key for the codebook based precoding. Novel VQ algorithm is proposed in this paper which needs less execution time and less n...
This paper introduces a novel approach to evaluate the performance of ad hoc networks based on their spatial capacity, defined as the maximum spatial spectral efficiency supported by the network while a zero outage probability is guaranteed for all communication links. Specifically, the spatial capacity together with upper and lower bounds is derived in closed-form for networks where transmitters...
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