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Coordinated multipoint transmission (CoMP) and soft frequency reuse (SFR) are two popular techniques used to control the deleterious effects caused by inter-cell interference in current 4G and envisaged 5G cellular networks. The performance of the combination of CoMP and SFR has been shown to be strongly influenced by the specific choice of the parameters governing the action of both mechanisms. Unfortunately,...
In order to improve the simultaneous wireless information and power transfer (SWIPT) efficiency, we exploit the vertical domain by adjusting the base station (BS) antenna tilt. In this paper, the single-cell multiple-input multiple-output (MIMO) SWIPT system is studied where one BS employs three-dimensional (3D) directional antennas and users apply the power splitting (PS) technique. With zero-forcing...
In this paper, we present the design of optimal precoders and receive filters for a full-duplex (FD) two-way amplify-and-forward (AF) multiple- input multiple-output (MIMO) relaying system in a cognitive radio network. The secondary user (SU) or cognitive nodes share the spectrum with the licensed primary user (PU) nodes while keeping the interference to PU nodes below a threshold. The cognitive transceivers...
Capacity-coverage tradeoff balancing is a classical but critical problem for practical wireless multi- cell network optimization. Increasing the average capacity is often at the expense of decreasing the cell coverage and vice versa. It becomes more complex in massive multiple-input/multiple-output (MIMO) networks to balance the above two performance indicators since capacity is much highly improved...
In this work, we solve a problem of antenna selection (AS) for a multiple-input multiple-output (MIMO) system under the constraint of the channel capacity maximization. The biogeography-based optimization (BBO) algorithm is applied on the joint transmitter and receiver AS for the channel capacity function. We apply different BBO migration models for simulated channels. The comparisons with other popular...
Abstract-In this paper, the problem of designing a linear precoder for Multiple-Input Multiple-Output (MIMO) systems in conjunction with Quadrature Amplitude Modulation (QAM) is addressed. First, a novel and efficient methodology to evaluate the input-output mutual information for a general Multiple-Input Multiple-Output (MIMO) system as well as its corresponding gradients is presented, based on the...
This paper studies the deployment of multiple- input multiple-output (MIMO) full-duplex (FD) relaying systems in a multi-cell environment, where a multi-antenna amplify-and-forward (AF) FD relay station serves multiple half-duplex (HD) multi-antenna users. The fundamental challenges of loopback self-interference (LI) and multiple co-channel interferers (CCI) at the relay and destination when incorporating...
In traditional cellular networks, cell edge users suffer from severe interference. This paper considers a cell free network scenario that multiple base stations (BSs) serve a group of users without cell boundary. Each user can only be served by its own BS according to the traditional cellular network paradigm, while in the user centric cell free network, users can be associated with multiple nearby...
Consensus-based algorithms are a welcome approach to establish cooperative communication systems. In this work, it has been utilized to present a hardware architecture for distributed data detection in a receiver with several sensor nodes on an easily scalable regular network. Additionally, it is capable to detect the transmitted message even if a single sensor node fails to operate. On top of that,...
Massive Multi-input Multi-output (MIMO) technique shows great potentials in improving energy and spectral efficiency while suffers high costs of the requirement for large amount of radio frequency (RF) chains. In this paper, we develop an ${l_{1/2}}$-regularity based downlink transmit antenna selection scheme for massive MIMO systems with limited RF chains. With the objective to minimize the transmission...
In this paper, we concentrate on introducing an optimized energy detection approach applied to cognitive MIMO. Firstly, the system with multiple secondary users is modeled and then the weighting factor of each secondary user is calculated and analyzed. Under the constraint that the quadratic sum of combination factors is unit, the optimal weighting factors of secondary users sharing some certain spectrum...
Beamforming for a cognitive radio system with a primary user and multiple secondary users is presented. It strives to create an interference-free environment for the primary user by cancelation of the secondary users' signals. The optimization objective is to maximize the signal-to-interference-plus-noise ratio (SINR) for the primary user through the transmit beamformers of all users and the receive...
In this paper, sum-rate maximization is investigated in a two-way MIMO relay network where a multi-antenna relay node assists two transceivers for exchanging their data. For sum-rate maximization, beamforming weights are designed whereas total transmit power constraint in the multi-antenna relay node is satisfied. Assuming that the second order statistics (SOS) of channel state information (CSI) are...
The physical layer security in a multi-user massive multiple-input multiple-output (MU-Massive-MIMO) system is considered in this paper, where a hidden eavesdropper (Eve) may eavesdrop the information signal of any legitimate user. Two distributed antenna system (DAS) aided power-saving transmit strategies are evaluated: 1) the autonomous full (AF) transmission with explicit artificial noise (AN),...
We study the precoding for the high-rank MIMO in the LTE-A Pro systems. Unlike the low-rank precoding, layer mapping has a relatively large impact on the performance for high-rank precoding. First, we construct a model on the relationship between layer mapping and precoding. Then we derive the system throughput with the resulting model, so that the performance of the layer mapping and precoding can...
This paper considers the design problem of Multiple-Input Multiple-Output (MIMO) radar space-time transmit code (STTC) and space-time receive filter (STRF) for a moving point-like target in the presence of signal-dependent interference. An iterative procedure, whose convergence is analytically proved, is devised to maximize the Signal to Interference plus Noise Ratio (SINR) accounting for both a similarity...
We consider a combined form of partial CSIT (Channel State Information at the Transmitter(s) (Tx)), comprising both channel estimates (mean CSIT) and covariance CSIT. In particular multipath induced structured low rank covariances are considered that arise in Massive MIMO and mmWave settings. For the beamforming optimization, we first revisit Weighted Sum Rate (WSR) maximization with perfect CSIT...
Phase adjusting and power adjusting input schemes of non-orthogonal Gaussian multiple access channels (GMAC) for two-user with finite input constellations have been studied. In this paper, the input scheme for multi-user is jointly optimized by both powers and phases. This scheme is deduced from the constellation constrained (CC) capacity of multi-user GMAC. Performance analysis indicates that the...
Recent results have revealed that massive multiple-input-multiple-output (MIMO) channels exhibit a sparse structure. In this paper, we leverage this feature into the development of a novel channel estimation algorithm, namely, the Adaptive-Least Absolute Shrinkage and Selection Operator (A-LASSO), in which the sparsifying matrix (dictionary) and the sparse vector are jointly optimized. The key ingredients...
The usage of hybrid network consisting of massive multiple input multiple output (MIMO) co-existing with small cell networks (SCNs), are considered to be a key technique for the future wireless communication systems. However, the co-existing SCNs not only require on-site hardware installation, but also increase the static power of the system thereby reducing the energy efficiency (EE). To circumvent...
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