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In a multiple-input multiple-output (MIMO) precoding system based on finite-rate feedback, the receiver sends a precoding matrix to the transmitter via a feedback channel. The overall system performance is degraded due to feedback error. In this paper, we propose a robust feedback scheme that employs the index permutation technique to provide the system with redundancy-free protection against the...
This paper considers two hop MIMO-OFDM AF relaying systems with separate power constraint at source and relay. In order to maximize the system capacity, the adaptive transmission is realized by two steps of beamforming with equal power and then power allocation. For the limited feedback scenario, we utilize the Grassmannian beamforming codebooks as the source and relay beamforming codebooks and design...
Previous work has shown that high frequency content is important for realistic haptic feedback, while stability considerations limit the ability of closed-loop control to effectively generate high frequencies. Open-loop playback of high frequencies offers a promising way to generate rich contact transients and textures, but complex high frequency dynamics cause distortion. This paper explores the...
This paper utilizes an adaptive modulation and coding (AMC) scheme and compares the performance of adaptation between single-user multiple input multiple output (SU-MIMO) and multi-user (MU) MIMO with that of SU-MIMO. In long term evolution (LTE), every UE only needs to feed back SU-MIMO rank 1 channel quality indicator (CQI) which could get feedback overhead and computational complexity reduction...
Coordination of MIMO transmission across multiple cells can effectively reduce cell-edge interference. However, downlink multi-cell MIMO transmission requires additional channel state information at the cooperating base stations compared to the single-cell case. Therefore, reducing the feedback overhead is an important issue in multi-cell MIMO systems. This paper proposes an adaptive feedback interval...
The mobile WiMAX standard (802.16e) uses multiple-input multiple-output (MIMO) limited feedback linear precoding to exploit the channel state information at the transmitter. Although the performance of limited feedback linear precoding in relation to traditional open-loop MIMO-OFDM has been extensively studied in the literature, these studies commonly assume perfect channel estimation at the receiver...
In this paper, we propose a precoder using a minimum mean-square error (MMSE) criterion for a non-regenerative relay system. It is assumed that the relay knows the channel covariance information (CCI) of the relay-destination link and the full channel state information (CSI) of the source-relay link. We start by assuming the precoder has a specified structure. We derive an upper-bound of the mean-square...
In wireless dual-hop decode-and-forward (DF) relaying networks, multiple relay stations (RS) and users construct a multiple-in-multiple-out (MIMO) broadcast channel (BC). Due to unpredictable decoding failure, scheduling the transmission for the decode-and-forward broadcast channel (DFBC) should depend on not only channel qualities but also the availability of errorless data at individual RSs. Based...
In this paper, we propose a novel low-complexity, multiple feedback successive interference cancellation (SIC) strategy for uncoded multiple-input multiple output (MIMO) spatial multiplexing systems. Since the complexity of the ML and the existing near ML algorithms such as the sphere decoder (SD) is still high in systems with bad channel conditions and/or low signal-noise ratio (SNR), there is a...
In this paper, we evaluate intercell interference can-celation techniques in cooperative downlink multicell systems. We compare two classical beamforming strategies for the design of the beamforming vectors: maximum ratio combining precoding and partial zero-forcing. Since full channel state information at the transmission is unfeasible, we consider a limited feedback link and compare different strategies...
This paper proposes an improved scheme for feedback error learning (FEL). In two-degree-of-freedom control systems in general, a prefilter is used to compensate the relative degree delay of a strictly proper plant. In conventional schemes of FEL, however, the feedforward controller has to learn parameter including the prefilter, although it is given in advance. The proposed scheme reduces this redundancy...
Coordinated Multi-Point transmission and reception (CoMP) technique is a new promising scheme which has been adopted in LTE-Advanced. For the next generation of wireless communication networks, CoMP is mostly required to reduce the inter-cell interference (ICI). It also increases the cell edge user throughput and improves the coverage. Recently, most research work based on precoding with feedback...
This paper proposes a codebook-based precoding method for multiple-input multiple-output (MIMO) amplify-and-forward (AF) relaying system. The proposed codeword selection criterion is a distributed codeword selection criterion which allows base station and relay to choose optimal precoding matrix independently. Therefore the feedback delay is decreased. Based on the proposed criterion, we further develop...
In this paper, we study the influence of training-based channel estimation on the information-theoretic capacity of closed-loop MIMO systems with imperfect channel state information (CSI) feedback. First, a lower bound on capacity is formulated as a function of various parameters such as received signal-to-noise ratio, number of training symbols, feedback delay time, and the feedback noise variance...
In the paper a multicontroller-based switchable control system structure is proposed to control nonlinear MIMO plants. The considered structure contains a set of linear feedback controllers operating together with an additional, statically decoupled loop of the control system. The nonlinear model of a drilling vessel in three degrees of freedom (3DOF) on the sea surface is used as a MIMO plant to...
We consider an optimal control problem of MIMO systems affected by external disturbances with known dynamic characteristics but unknown initial conditions based on stability degree constraint. The objective is to find an optimal control, by which the cost function minimum and the state with the optimal control having a higher mean-square convergence rate can be obtained. A feedforward and feedback...
We investigate the effects of imperfect channel knowledge and feedback in incremental-redundancy automatic-repeat request (INR-ARQ) coding systems over multiple-input multiple-output (MIMO) block-fading channels. We propose an ARQ decoder based on nearest neighbour decoding and evaluate the corresponding achievable rates. We then derive the optimal code diversity assuming that the feedback channel...
This paper considers the optimal tracking control (OTC) problem for MIMO systems affected by external disturbances based on stability degree constraint. The objective is to find an OTC, by which the cost function minimum and the state with the OTC having a higher mean-square convergence rate can be obtained. According to the special disturbance form, by supposing the Lagrange operator to solve the...
In this paper, a novel multiuser MIMO downlink transmission scheme with limited feedback and linear precoding is proposed, using maximum signal-to-jamming and noise ratio (SJNR) criterion. According to the analysis of the criterion, it is shown that the multiplexed users with high channel gain but low correlation with each other may bring high system capacity. For the limited feedback scenario, we...
A new adaptive decoupling control algorithm is presented for a family of complex MIMO systems with strong couplings and severe nonlinearity such as the hovering submarines. The couplings between different channels are decoupled with the modified Feedback Decoupling Control Algorithm (MFDC), and the subsystems is adjusted with the online parameters estimation algorithm based on the neural networks...
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