An Optimal Power Allocation Scheme in Downlink Multi-user NOMA Beamforming System with Imperfect CSI

2018 ◽  
Author(s):  
Xiaoguang Liu ◽  
Jun Zhang ◽  
Shu Cai
Keyword(s):  
Power Allocation ◽  
Optimal Power Allocation ◽  
Allocation Scheme ◽  
Imperfect Csi ◽  
Optimal Power

An Optimal Power Allocation for the Two-Way Relay System Using Physical-Layer Network Coding

2014 ◽  
Vol 986-987 ◽  
pp. 2041-2047
Author(s):  
Ren Gang Yuan ◽  
Li Li Chu ◽  
Chuang Li ◽  
Ling Li Cao
Keyword(s):  
Power Allocation ◽  
Network Coding ◽  
Physical Layer ◽  
Optimal Power Allocation ◽  
Relay Channel ◽  
Allocation Scheme ◽  
Relay System ◽  
Physical Layer Network Coding ◽  
Optimal Power ◽  
Sum Rate

In this letter, an optimal power allocation in the two-way relay channel of four transmission nodes employing the physical-layer network coding (PNC) protocol is proposed to improve the network sum-rate of the two-way relay system. The optimal power allocation is obtained by maximizing the network sum-rate of the PNC protocol under a sum-power constraint in a Rayleigh fading channel environment. Analytical and simulation results show that the proposed power allocation can improve the network sum-rate. Furthermore, compared with the equal power allocation scheme, the proposed power allocation scheme can achieve much higher network sum-rate performance.

scholarly journals An Optimal Power Allocation Scheme of Microgrid Using Grey Wolf Optimizer

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 137608-137619 ◽  
Author(s):  
Jiancheng Zhang ◽  
Xinsheng Wang ◽  
Lingyu Ma
Keyword(s):  
Power Allocation ◽  
Grey Wolf Optimizer ◽  
Optimal Power Allocation ◽  
Grey Wolf ◽  
Allocation Scheme ◽  
Optimal Power

Secrecy Rate and Optimal Power Allocation of the Amplify-and-Forward Relay Wire-Tap System

2016 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Cuong Dang ◽  
Leonardo J. Rodr´ıguez ◽  
Nghi H. Tran ◽  
Forrest Sheng Bao ◽  
Shivakumar Sastry
Keyword(s):  
Power Allocation ◽  
Secrecy Capacity ◽  
Optimal Power Allocation ◽  
Allocation Scheme ◽  
Amplify And Forward ◽  
Secrecy Rate ◽  
Joint Power ◽  
Power Constraints ◽  
Optimal Power ◽  
Af Relay

In this research work, we investigate the secrecy rate and optimal power allocation schemes for a half-duplex (HD) wire-tap Rayleigh fading channel in which a source wishes to communicate securely to a destination in the presence of an eavesdropper and under the aid of an amplify-and-forward (AF) relay. The secrecy capacity and the corresponding optimal power allocation schemes are examined under both individual and joint power constraints. Due to the absence of an insightful expression of the secrecy rate for a given power allocation scheme, determining such secrecy capacity is challenging. To overcome this issue, we first propose a novel method to calculate the expectation of an exponentially distributed random variable using the exponential integral function. By exploiting this calculation, we then establish the average secrecy rate of the considered AF relay channel in closed-form. By examining the quasi-concavity of the optimal power allocation problem, it is then concluded that the problem is quasi-concave. As such, the globally optimal solution exists and is unique for both individual and joint power constraints. A simple root finding method then can be applied into the derived close-formed formula to approximately calculate the optimal power allocation scheme to achieve the secrecy capacity. Numerical results are then provided to confirm the accuracy of the derived formula and the optimality of the proposed power allocation.

scholarly journals An optimal power allocation scheme for the STC hybrid-ARQ over energy limited networks

2009 ◽  
Vol 8 (12) ◽  
pp. 5718-5722 ◽  
Author(s):  
Hongbo Liu ◽  
Leonid Razoumov ◽  
Narayan Mandayam ◽  
Predrag Spasojevic
Keyword(s):  
Power Allocation ◽  
Optimal Power Allocation ◽  
Allocation Scheme ◽  
Hybrid Arq ◽  
Optimal Power

scholarly journals The Optimal Power Allocation with Hybrid Relaying Based on Channel Condition

2018 ◽  
Author(s):  
Junpyo Jeon ◽  
Yeonggyu Shim ◽  
Hyuncheol Park
Keyword(s):  
Power Allocation ◽  
Relay Network ◽  
Achievable Rate ◽  
Optimal Power Allocation ◽  
Allocation Scheme ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Transmit Power ◽  
Optimal Power ◽  
Af Relay

This paper considers a hybrid relay network consisting of the source, the amplify-and-forward (AF) relay, the decode-and-forward (DF) relay, and the destination. We propose the optimal power allocation schemes between two different relays which maximize the achievable rate under a sum relay power constraint for given channel gains and transmit power from source. By solving the optimization problem to maximize the achievable rate for each relay network, the transmit power values in closed-form are derived. When the channel gains are the same, the optimal power allocation scheme for AF-DF relay network proves that a more power should be allocated at the first relay to maximize the achievable rate. In case of the DF-AF relay network, we derive the optimal power allocation scheme for the possible four cases. Under the same SNR condition at the first hop, we show that the achievable rate of AF-DF relay network is greater than that of DF-AF relay network when the channel gain between two relays is higher than that between the second relay and destination. Simulation results show that the proposed power allocation schemes provide a higher achievable rate than the equal power allocation schemes.

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