Subcarrier and Power Allocation Algorithm for Spectral Efficiency Maximization in Superposition Coding OFDMA Systems

2015 ◽  
Vol 24 (05) ◽  
pp. 1550061
Author(s):  
Mateus de Paula Marques ◽  
Taufik Abrão
Keyword(s):  
Power Allocation ◽  
Spectral Efficiency ◽  
Time Complexity ◽  
Multiple Access ◽  
Optimization Problem ◽  
Frequency Division ◽  
Superposition Coding ◽  
Ofdma System ◽  
Transmission Strategy ◽  
Throughput Gain

This paper addresses the optimization problem on subcarrier and power allocation of orthogonal frequency division multiple access (OFDMA) system under spectral efficiency (SE) metric when deploying superposition coding (SC) transmission strategy. An algorithm with polynomial time complexity, of the order of (UN log 2(N)) has been proposed for sub-optimal SE maximization. Results indicate that the system SE increases with the use of SC technique. Besides, the throughput gain with SC adoption increases when the number of users (U) approaches the number of subcarriers (N) available in the system.

scholarly journals Clustering and Auction-Based Power Allocation Algorithm for Energy Efficiency Maximization in Multi-Cell Multi-Carrier NOMA Networks

2019 ◽  
Vol 9 (23) ◽  
pp. 5034 ◽  
Author(s):  
Abuzar B. M. Adam ◽  
Xiaoyu Wan ◽  
Zhengqiang Wang
Keyword(s):  
Energy Efficiency ◽  
Power Allocation ◽  
Cooperative Game ◽  
Multiple Access ◽  
Optimization Problem ◽  
Interference Mitigation ◽  
Base Stations ◽  
Frequency Division ◽  
Simulation Results ◽  
Inter Cell Interference

In this paper, we investigate the energy efficiency (EE) maximization in multi-cell multi-carrier non-orthogonal multiple access (MCMC-NOMA) networks. To achieve this goal, an optimization problem is formulated then the solution is divided into two parts. First, we investigate the inter-cell interference mitigation and then we propose an auction-based non-cooperative game for power allocation for base stations. Finally, to guarantee the rate requirements for users, power is allocated fairly to users. The simulation results show that the proposed scheme has the best performance compared with the existing NOMA-based fractional transmit power allocation (FTPA) and the conventional orthogonal frequency division multiple access (OFDMA).

scholarly journals Energy Efficiency and Spectral Efficiency Tradeoff in Massive MIMO Multicast Transmission with Statistical CSI

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 1045
Author(s):  
Bin Jiang ◽  
Bowen Ren ◽  
Yufei Huang ◽  
Tingting Chen ◽  
Li You ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Power Allocation ◽  
Spectral Efficiency ◽  
Massive Mimo ◽  
Communication Systems ◽  
Multicast Transmission ◽  
Transmission Strategy ◽  
Trade Offs ◽  
Core Technology ◽  
System Resource

As the core technology of 5G mobile communication systems, massive multi-input multi-output (MIMO) can dramatically enhance the energy efficiency (EE), as well as the spectral efficiency (SE), which meets the requirements of new applications. Meanwhile, physical layer multicast technology has gradually become the focus of next-generation communication technology research due to its capacity to efficiently provide wireless transmission from point to multipoint. The availability of channel state information (CSI), to a large extent, determines the performance of massive MIMO. However, because obtaining the perfect instantaneous CSI in massive MIMO is quite challenging, it is reasonable and practical to design a massive MIMO multicast transmission strategy using statistical CSI. In this paper, in order to optimize the system resource efficiency (RE) to achieve EE-SE balance, the EE-SE trade-offs in the massive MIMO multicast transmission are investigated with statistical CSI. Firstly, we formulate the eigenvectors of the RE optimization multicast covariance matrices of different user terminals in closed form, which illustrates that in the massive MIMO downlink, optimal RE multicast precoding is supposed to be done in the beam domain. On the basis of this viewpoint, the optimal RE precoding design is simplified into a resource efficient power allocation problem. Via invoking the quadratic transform, we propose an iterative power allocation algorithm, which obtains an adjustable and reasonable EE-SE tradeoff. Numerical simulation results reveal the near-optimal performance and the effectiveness of our proposed statistical CSI-assisted RE maximization in massive MIMO.

scholarly journals A New Swap-Based Frequency-Domain Packet Scheduling Algorithm in OFDMA System with Data Queue Size Constraints

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Lin Shao ◽  
Yunxiao Zu ◽  
Hanyong Shao
Keyword(s):  
Frequency Domain ◽  
Multiple Access ◽  
Packet Scheduling ◽  
Scheduling Algorithm ◽  
System Throughput ◽  
Queue Size ◽  
Frequency Division ◽  
Ofdma System ◽  
Size Constraints ◽  
Throughput Improvement

This paper aims at the frequency-domain packet scheduling (FDPS) problem in orthogonal frequency division multiple access (OFDMA) system. Under users’ data queue size constraints, a new swap-based FDPS algorithm is proposed to achieve further improvement in system throughput. In this algorithm, the swap of physical resource blocks (PRBs) between different users is introduced to give a comprehensive view of the overall scheduling process. Moreover, the proposed algorithm optimizes the choosing method of swap candidates and always tries to select the user who can maximize the throughput improvement. Simulation results demonstrate that this new algorithm can improve the system throughput significantly as well as reduce the resource waste effectively.

scholarly journals NOMA for Multinumerology OFDM Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Ayman T. Abusabah ◽  
Huseyin Arslan
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Access ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Superposition Coding ◽  
Promising Technique ◽  
Successive Interference Cancelation ◽  
Power Domain ◽  
Multiple Access Schemes ◽  
Spectrally Efficient

Nonorthogonal multiple access (NOMA) is a promising technique which outperforms the traditional multiple access schemes in many aspects. It uses superposition coding (SC) to share the available resources among the users and adopts successive interference cancelation (SIC) for multiuser detection (MUD). Detection is performed in power domain where fairness can be supported through appropriate power allocation. Since power domain NOMA utilizes SC at the transmitter and SIC at the receiver, users cannot achieve equal rates and experience higher interference. In this paper, a novel NOMA scheme is proposed for multinumerology orthogonal frequency division multiplexing system, that is, different subcarrier spacings. The scheme uses the nature of mixed numerology systems to reduce the constraints associated with the MUD operation. This scheme not only enhances the fairness among the users but improves the bit error rate performance as well. Although the proposed scheme is less spectrally efficient than conventional NOMA schemes, it is still more spectrally efficient than orthogonal multiple access schemes.

scholarly journals Throughput Analysis for Non-Orthogonal Multiple Access (NOMA)-Based 5G Networks

2019 ◽  
Vol 8 (3S) ◽  
pp. 101-108
Keyword(s):  
Power Allocation ◽  
Interference Cancellation ◽  
Multiple Access ◽  
System Throughput ◽  
Superposition Coding ◽  
5G Networks ◽  
Throughput Analysis ◽  
Radio Access ◽  
5G Network ◽  
High System

Non-Orthogonal Multiple Access (NOMA) scheme is one of the emerging radio access techniques to enhance the system performance for 5G networks. The powerdomain NOMA is one of the basic NOMA schemes that perform superposition coding (SC) at the transmitter and successive interference cancellation (SIC) at the receiver. Power Allocation (PA) plays a significant role in attaining successful SIC and high system throughput. This work is focusing on power allocation to maximize the throughput for NOMA-based 5G network. The objective functions, algorithms, constraints and limitations of the system design in power allocation techniques for NOMA-based 5G networks in terms of throughput analysis are extensively investigated and reported.

scholarly journals Max–Min Fairness Optimization for D2D Communications Coexisting with Cellular Networks

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1422
Author(s):  
Hoai Giang Nguyen ◽  
Xuan Tung Nguyen ◽  
Van Son Nguyen ◽  
Trinh Van Chien ◽  
Tien Hoa Nguyen ◽  
...  
Keyword(s):  
Spectral Efficiency ◽  
Multiple Access ◽  
Optimization Problem ◽  
Mutual Interference ◽  
D2d Communications ◽  
Power Budget ◽  
Good Service ◽  
Coverage Area ◽  
Channel Condition ◽  
Simulation Results

This paper considers a system consisting of a nonorthogonal multiple access (NOMA)-based device-to-device (D2D) communication system within a cellular network, in which the time and frequency resources are shared by everyone. In particular, D2D groups that constitute different pairs are assigned to the subchannels that the cellular users occupy. A max–min fairness optimization problem with power budget constraints is formulated and solved in this paper to reduce the mutual interference between the cellular users and D2D devices that substantially impacts that with the worst channel condition. For a low computational complexity solution, we propose the use of the bisection method together with the solution of a system of linear equalities. The proposed algorithm can provide uniformly good service to all of the cellular users and D2D devices in the coverage area by utilizing the minimal total transmit power. The simulation results indicate the effectiveness of the proposed algorithm in the improvement of the spectral efficiency of the worst user under the different widely used subchannel assignments and pairing techniques.

Sign in / Sign up

Export Citation Format

Share Document