This paper investigates the problem of energy efficient relay precoder design in multiple-input multiple-output cognitive relay networks (MIMO-CRNs). This is a non-convex fractional programming problem, which is tradi...
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This paper investigates the problem of energy efficient relay precoder design in multiple-input multiple-output cognitive relay networks (MIMO-CRNs). This is a non-convex fractional programming problem, which is traditionally solved using computationally expensive optimization methods. In this paper, we propose a deep learning (DL) based approach to compute an approximate solution. Specifically, a deep neural network (DNN) is employed and trained using offline computed optimal solution. The proposed scheme consists of an offline data generation phase, an offline training phase, and an online deployment phase. The numerical results show that the proposed DNN provides comparable performance at significantly lower computational complexity as compared to the conventional optimization-based algorithm that makes the proposed approach suitable for real-time implementation. (C) 2021 Published by Elsevier B.V.
This paper deals with the global optimality of the channel capacity of the multiple-input multiple-output (MIMO) cooperative system which is equipped with precoders at source and relay, and exploits the direct channel...
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This paper deals with the global optimality of the channel capacity of the multiple-input multiple-output (MIMO) cooperative system which is equipped with precoders at source and relay, and exploits the direct channel between source and destination. Each precoder of the system is individually designed by the Lagrangian method and the final precoders are decided by an iterative structure. To prove the global optimality for the channel capacity of the system with these joint precoders, we show that the channel capacity function of the system is a concave function and the constraints of the system are convex sets.
We consider a relay network with a single source-destination pair and multiple layers of relays between them. We assume that these layers sequentially relay the signal transmitted by the source to the destination. Unl...
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We consider a relay network with a single source-destination pair and multiple layers of relays between them. We assume that these layers sequentially relay the signal transmitted by the source to the destination. Unlike existing work, we also assume that the destination and all the forward layers present between the transmitting layer and the destination receive signals during every transmission phase. We optimally combine these signals, say mu of them, using a precoder at each relay layer for onward transmission. We obtain this precoding matrix by minimizing the mean-squared error (MSE) at the relays, and do not require channel-state- information (CSI) of the forward channels at the relays unlike existing systems that minimize MSE at the destination and require CSI of the forward channels at the relays. Our closed-form solution for this matrix is valid for any K number of layers, whereas minimizing MSE at the destination does not have closed-form solution for K > 1. For K > 1, we enhance an existing scheme to obtain a sub-optimal closed-form precoder solution and use it for comparison. We show using simulations that our scheme approaches the bit-error-rate (BER) performance of this scheme, when mu is increased, even with partial CSI.
This study examines the linear source and relay precoder and destination combiner design for multiple-input multiple-output full-duplex (FD) relay communication systems. The effect of the residual interference due to ...
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This study examines the linear source and relay precoder and destination combiner design for multiple-input multiple-output full-duplex (FD) relay communication systems. The effect of the residual interference due to the imperfect loop interference cancellation is considered in the design. Two design algorithms are proposed to minimise the mean squared error of the received signal at the destination. The first is a tri-step alternating iterative algorithm while the second is a bi-step iterative algorithm, which has lower complexity and performance comparable to that of the first algorithm. The convergence of these algorithms is evaluated. Results are presented, which show that the proposed FD relay system can provide approximately double the achievable rate of the corresponding half-duplex system if the residual interference is not high.
This chapter presents a novel AF relay design for a MIMO relay network optimization under received power constraint. With no CSI at the source, the optimum multiple relay precoders of a MIMO relay network are devised ...
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ISBN:
(纸本)9783319173146;9783319173139
This chapter presents a novel AF relay design for a MIMO relay network optimization under received power constraint. With no CSI at the source, the optimum multiple relay precoders of a MIMO relay network are devised for combating the backward non-flat-fading channels. Simulation cases in terms of BER performance validate the proposed relay design and justify the proposed approach in its ability to pursue an optimum delay transmitted block for detection at the receiver.
The joint design of the multi-stream in MIMO relay sigle/multiple user system is investigated. Under the inter-stream interference, a constrained optimization problem with respect to the unknown relay precoder matrix ...
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ISBN:
(纸本)9781467325691
The joint design of the multi-stream in MIMO relay sigle/multiple user system is investigated. Under the inter-stream interference, a constrained optimization problem with respect to the unknown relay precoder matrix is formulated with a goal of minimizing the total relay transmit power subject to quality of service (QoS) requirement on each data stream. As the original opitimization problem is non-convex, the matrix expression of the cost function and constrained requirement is converting to a scalar optimization problem and the optimal relay precoder and receive filter are obtained. The optimal design of the multiple user relay system under QoS requirement is also provided. By using a reasonable approximation and converting to the generalized Rayleigh form for the cost function, a suboptimal relay precoder matrix for QoS optimization with relay transmit power constraint is obtained. Simulation results demonstrate that for single user model, the minimize relay power will increase with Signal to Interference plus Noise Ratio(SINR) constraint value becoming larger, and for multiple users model, more users in our algorithm will make the MSE gain more obvious as increasing transmitting SNR.
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