Toward Green Power Allocation in Relay-Assisted Multiuser Networks: A Pricing-Based Approach

Abstract

Green communications have been emerged as a demanding concept for improving the network energy efficiency (EE). In this paper, a pricing-based approach is investigated to achieve energy-efficient power allocation in relay-assisted multiuser networks. We introduce a network price to the power consumption as a penalty for the achievable sum rate, and study its impact on the tradeoff between the EE and the spectral efficiency (SE). It is hard to directly solve the problem as it is non-convex, and thus a concave lower bound on the pricing-based utility is applied to transform the problem into a convex one. Through dual decomposition, a q-price algorithm is proposed for iteratively tightening the lower bound and finding the optimal solution. In addition, an optimal price that enables green power allocation is defined and found from the viewpoint of maximizing EE. We further analyze the optimal power allocation strategies of the pricing-based approach in a two-user case under different noise operating regimes, yielding on-off, water-filling, and channel-reversal approaches, etc. Finally, the performance of the proposed approach is evaluated by computer simulations, and we characterize the interaction between the EE and SE for various network parameters when the network is designed from the energy-efficient perspective.Index Terms-Green communications, multiuser relay networks, energy efficiency, power allocation.

Energy-Efficient User Association with Open Loop Power Control for Uplink HCNs

“…In the first type, we can use bisection method to search the solution in feasible domain [32]. In the other type, we can adopt an iterative algorithm to update γ while ensuring that the corresponding solution x remains feasible in each iteration [33]. Considering that it is difficult for designers to find the tight bound of γ in the first type, we primarily focus on the second type.…”

A Utility-Based Joint Subcarrier and Power Allocation for Green Communications in Multi-User Two-Way Regenerative Relay Networks

“…Since the bound in (19) is tight at θ = θ 0 then log(1+θ 0 ) = x log(θ 0 ) + y. Substituting the value of y, i.e., y = log(1 + θ 0 ) − x log(θ 0 ) in (19) we get…”

“…However, only a few works have considered the EE as a key metric for designing the optimal resource allocation policies in the relay networks [18]- [24]. In [18], a joint power control and antenna beamforming algorithm was proposed to maximize EE in very large multi-user MIMO systems, whereas a pricing-based power allocation scheme for multi-user AF relay networks was investigated in [19] and the trade-off between EE and SE was studied for multi-user MIMO systems in [20]. The authors in [22] have proposed a joint power and subchannel allocation for OFDMA-based twoway relay networks, wherein same subchannel is assigned to the multiple access (MA) and the broadcast (BC) phase and thus, the subchannel assignment and power allocation schemes limit the network performance.…”

“…• In contrast to [19], [22]- [24], a network pricing-based approach, which enables us to strike a balance between the achievable sum rate and power consumption in the relay networks, is proposed for considered resource allocation problem. Through a joint optimization of subcarrier pairing permutation, subcarrier allocation and power allocation all together, we intend to maximize the pricing-based network utility function in multi-user multicarrier two-way DF relay network subject to limited transmit power, subcarrier pairing, and subcarrier allocation constraints.…”

Energy-Efficient Subcarrier Pairing and Power Allocation for DF Relay Networks with an Eavesdropper

“…The transmit power relies upon instantaneous channel coefficients, while the static power involves the processing and circuit power. Therefore, we define the total power dissipation in the network as follows [6]:…”