Energy-Efficient Resource Allocation in Single-RF Load-Modulated Massive MIMO HetNets

Abstract

Due to the dramatic increase in wireless data traffic and the associated increase in energy consumption, designing energy-efficient wireless networks with improved spectral efficiency is a pressing concern. The focus of this paper is the design of a green, highly energy-efficient cellular heterogeneous network (HetNet) by taking advantage of multiple-input-multiple-output (MIMO) structure and deployment of small cells. We consider the downlink of a two-tier HetNet, in which multiple-antenna small cells are coordinated to serve users. Even though the deployment of MIMO together with small cells improves the communication system's performance in terms of data rate and reliability, circuit energy consumption in such a network is a critical issue. To address this, an energy-efficient antenna selection and radio resource block assignment algorithm is proposed for the small cells, and a single radio-frequency (RF) chain structure is considered for the massive MIMO macro base station. Then, while coordinating transmissions between cells subject to user-centric clustering, an energy-efficient beamforming design and power allocation optimization problem with respect to the quality of service requirement of users, transmit power budget of base stations, and fronthaul capacity is formulated; the problem is solved using the Dinkelbach method. Simulation results demonstrate the performance potential of our proposed algorithm in terms of energy efficiency and spectral efficiency.

Joint Channel and Phase Noise Estimation and Data Detection for GFDM

“…The complexity growth of the steps in each iteration is summarized in Table II. Similar to Algorithm 1, since the maximum value of is equal to and the number of time-slots is relatively small, the computational complexity of our estimator is roughly in the order of 3 .…”

“…F IFTH generation (5G) and beyond 5G wireless communication networks must handle peak data rates of at least 1 Tb/s, over-the-air latency of 10-100 s, user-experienced data rates of 1 Gb/s and the support of high user mobility (≥ 1000 km/h) [1]- [3]. Although 4G wireless (Long Term Evolution (LTE) and other standards) widely uses orthogonal frequency division multiplexing (OFDM), its drawbacks include high peak-to-average power ratios, bandwidth loss associated with the cyclic prefix (CP), high out-of-band (OOB) emissions emanating from rectangular filters, and high synchronisation issues due to orthogonality mismatch.…”

Non-Cooperative Game Based Power Allocation for Energy and Spectrum Efficient Downlink NOMA HetNets

“…On the other hand, maximizing EE by controlling the allocated power for interference management in HetNets has been studied in literature [8], [16]- [24]. A Dinkelbach based method is utilized to solve the HetNets EE maximization problem in [16]- [18], where the Dinkelbach is combined with PC time switching control in [16] and combined with the Lagrange dual decomposition (LDD) method to obtain a closed form expressions for the optimal PC in [17]. Moreover, Dinkelbach is joined with PC non-cooperative game in [18].…”

“…where 0 < w m < 1 is the balancing parameter between EE and SE within the MC. Although problems in (17) and (18) are linear, they are functions of inseparable variables, p…”

“…In other words, the transmitted power from one of the BSs affects the other cells negatively through either cross-tier or co-tier interference. Thus, problems in (17) and (18) are non-convex with respect to p [S] i and p [M ] which is computationally costly to be optimally solved. To solve (17) and (18), we propose to perform a non-cooperative game among BSs through which each BS can optimize its power individually while considering the power of other BS's as constant.…”