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This paper considers a two user Gaussian multiple-input single-output (MISO) broadcast channel with a per-antenna peak power constraint (or simply peak power constraint). It is more realistic to consider the peak power constraint on each transmit antenna because each antenna is equipped with its own power amplifier in many practical implementations. Assuming the perfect channel state information (CSI)...
The Golden Code is a full-rate full-diversity space-time code, which achieves maximum coding gain for Multiple-Input Multiple-Output (MIMO) systems with two transmit and two receive antennas. Since four information symbols taken from an M-QAM constellation are selected to construct one Golden Code codeword, a maximum likelihood decoder using sphere decoding has the worst-case complexity of O(M4),...
We consider a MIMO relay downlink system using precoding and limited feedback from two-hop channels. Since the conventional precoding matrices are directly obtained by treating the quantized channel state information (CSI) feedback as the real CSI, we propose an improved relay precoding strategy by taking the effect of channel quantization error into account. The proposed relaying technique is designed...
Coordinated multi-point (CoMP) transmission is a promising technique to suppress inter-cell interference (ICI) in LTE-Advanced system. With perfect channel state information (CSI) at the transmitter, joint beamforming methods can be used to completely cancel ICI and significantly improve the spectrum efficiency. However, in FDD system, the transmitter can't obtain perfect CSI to eliminate ICI, for...
Multiple-input multiple-output (MIMO) Beamforming (BF) performance is analyzed for amplify-and-forward (AF) fixed two-hop relay networks in independent and identically distributed (i.i.d.) Rayleigh fading channels. A novel performance bound using a new symbol-error-rate (SER) approximation is presented for AF relay networks equipped with multiple antennas at the source, relay, and destination when...
The paper considers a wireless network in which simultaneous communications occur within multiple single antenna source-destination node pairs. An Amplify-and-Forward (AF) relay, equipped with multiple antennas, assists the communication. The relay implements linear beamforming (BF) aiming to minimize the total relay power subject to signal-to-interference ratio (SINR) constraints for each source-destination...
This paper studies the joint design of transmit beamformers, receive combiners, and linear relaying matrix for a two-way amplify-and-forward (AF) relay system equipped with multiple-antennas at sources and relay. A single data stream is transmitted by each source. Due to the non-convexity of the optimization problem, finding a solution that maximizes the sum-rate appears to be intractable. Hence,...
In this paper, we design a new class of cross-layer opportunistic channel access scheduling framework for multiple-input multiple-output (MIMO) networks through exploitation of channel distribution information (CDI) in a form of full spatial correlation matrix. Due to propagation delay, infrequent channel updates, and time-varying node position, channel knowledge becomes outdated and scheduler based...
We study the achievable rate regions of the multiple-input multiple-output (MIMO) interference channel with confidential messages sent to two receivers. Under this model, each receiver is an eavesdropper for the other link and tries to decode both its own message and the message intended for the other receiver. We describe several transmission schemes for Gaussian interference channels and derive...
When channel state information is available at the transmitter, it can be exploited to increase the throughput, or to enhance the performance of a multiple input multiple output (MIMO) system. Beamforming schemes, such as closed loop MIMO and transmit beamforming constitute efficient means to achieve the aforementioned objectives. A significant shortcoming of transmit beamforming schemes is the signaling...
Beamforming is one of the key techniques for the multiple-input multiple-output (MIMO) wireless communication systems, which enables the system to achieve higher performance. In this paper, the Grassmann codebooks are employed to quantize channel state information (CSI) in the MIMO downlink for Long Term Evolution (LTE). Further more, a novel beamforming (BF) scheme based on the proposed equivalent...
Instead of using eigen-beamforming approach to increase capacity gain, an optimal weight scheme is employed in the closed-loop multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (MIMO-OFDM) wireless system design. In particular, this scheme provides an uplink scale weight vector pre-weighting space-time block code (STBC) signals at each transmit sub-carrier in accordance...
This paper aims at investigating the required feedback to achieve the Degrees of freedom (DoF) of X channel. Accordingly, a fixed precoding approach is proposed and is argued can achieve the DoF of such channel, assuming the channel state information is partially available at each transmitter through a feedback mechanism. This is achieved through using the notion of ergodic interference alignment...
In this work, we study the downlink of multiuser multiantenna systems which employ one multiple-input multiple-output (MIMO) relay and the amplify-and-forward (AF) relay strategy. We propose joint constrained optimization frameworks that consider the allocation of power levels between the base station (BS) and the relay station (RS) subject to a total power constraint and the joint design of BS precoders,...
In this paper, we consider the network multipleinput multiple-output (MIMO) where the base stations (BS) exchange only channel state information (CSI) to jointly design their transmission strategy. We particularly focus on a signal-tointerference-plus-noise ratio (SINR) balancing problem. First, the achievable rate regions with symmetric complex (SC) and asymmetric complex (AC) signaling techniques...
We present a new robust feedback and transmit strategy for multiuser MIMO downlink communication systems, termed Rate Approximation (RA), and analyze its performance. The new scheme combines flexibility and robustness needed for reliable communications with the user terminal, under a limited feedback constraint. The scheme responds to two major developments in the recent literature: One observation...
In this paper MIMO ad hoc wireless network performance in terms of signal-to-interference-plus-noise-ratio (SINR) for two physical layers models is considered. We analyze and discuss the performance of MIMO spatial multiplexing with dominant eigenvalue transmission, when the the beamforming weights are chosen as 1) dominant eigenvector, and 2) adaptive weights that adjusted to instantaneous interference...
In this paper we present a new paradigm for multiuser MIMO downlink communications called Rate Approximation with significant impact on the upcoming LTE standard. Rate Approximation combines flexibility and robustness needed for reliable communications with the terminal in the downlink and taking advantage of the channel state information. The scheme responds to two major developments in the recent...
We propose an interference-aware user selection scheme for uplink multiuser multiple-input multiple-output (MU-MIMO) systems in a multicell environment. The proposed scheme works in a distributed manner. Each mobile station (MS) determines its transmit beamforming vector based on the locally available channel state information (CSI), and informs the associated base station (BS) of the amount of potential...
Cooperative communication has been receiving significant attention in recent years because of the great potential for performance improvement. In this paper, we will consider the joint design of transmit and cooperative beamforming vectors in cooperative systems with a multi-antenna source and multiple single-antenna relays. The cooperative beamforming, performed by distributed relay nodes, is different...
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