In this paper,a utility-based feedback delay-aware and buffer status-aware( FABA) scheduling scheme is proposed for downlink multiuser multiple-input multiple-output orthogonal frequency-division multiple-access( MIMO...In this paper,a utility-based feedback delay-aware and buffer status-aware( FABA) scheduling scheme is proposed for downlink multiuser multiple-input multiple-output orthogonal frequency-division multiple-access( MIMO-OFDMA) systems. The FABA scheme allocates subcarriers to multiusers with an objective of not only maximizing the total system capacity but reducing the system packet loss rate as well. We design a utility function which consists of a feedback estimate module,a proportional fairness module and a buffer monitoring module. The feedback estimate module is used to improve the system throughput by utilizing the Automatic Repeat-reQuest( ARQ) feedback information to combat the fast time-varying fading condition. The proportional fairness module can guarantee the scheduling fairness among users,and the buffer monitoring module can utilize the transmitting buffer status information to avoid high packet loss rate of the system caused by the system congestion. The FABA scheme then formulates the scheduling problem into a problem of overall system utility maximization. We solve the problem by using a heuristic algorithm with low computational complexity. The simulation results show that the proposed FABA scheme outperforms the existing algorithms in terms of the system throughput and the packet loss rate and can also guarantee the fairness demand among users.展开更多
MIMO-OFDMA is a promising technique for future broadband wireless communication systems. In this paper, the problem of allocating subcarriers among different users to maximize the total capacity is addressed. The opti...MIMO-OFDMA is a promising technique for future broadband wireless communication systems. In this paper, the problem of allocating subcarriers among different users to maximize the total capacity is addressed. The optimal solution can be obtained by Hungarian method is proved, using two utility matrices, i.e. the Frobenius-norm matrix and the determinant matrix. Simulation results show that the proposed algorithm can achieve higher capacity than the existing algorithms, and it is globally optimal and easy to be implemented.展开更多
Beamforming is a kind of signal processing technique which can improve system performance in the multiple-input multiple-output(MIMO)systems.In this paper,the problem of allocating subcarriers in MIMO-OFDMA wireless s...Beamforming is a kind of signal processing technique which can improve system performance in the multiple-input multiple-output(MIMO)systems.In this paper,the problem of allocating subcarriers in MIMO-OFDMA wireless systems was analyzed,and a scheme to allocate subcarriers among all users based on beamforming was proposed to maximize the signal-to-noise ratio(SNR)at the receiver.Statistical properties of the channel matrix were studied,and some beneficial results were got.Statistical channel state information(CSI)was also taken into account to simulate more practical systems.Simulation results show that the proposed allocating scheme is effective,and it is robust to the influence of delayed CSI.展开更多
基金Sponsored by the National High Technology Research and Development Program of China(863 Program)(Grant No.2012AA01A508)the National Natural Science Funds of China for Young Scholar(Grant No.61302080)the Central Universities Research and Innovation Program of China for Young Scholar(Grant No.2013RC0112)
文摘In this paper,a utility-based feedback delay-aware and buffer status-aware( FABA) scheduling scheme is proposed for downlink multiuser multiple-input multiple-output orthogonal frequency-division multiple-access( MIMO-OFDMA) systems. The FABA scheme allocates subcarriers to multiusers with an objective of not only maximizing the total system capacity but reducing the system packet loss rate as well. We design a utility function which consists of a feedback estimate module,a proportional fairness module and a buffer monitoring module. The feedback estimate module is used to improve the system throughput by utilizing the Automatic Repeat-reQuest( ARQ) feedback information to combat the fast time-varying fading condition. The proportional fairness module can guarantee the scheduling fairness among users,and the buffer monitoring module can utilize the transmitting buffer status information to avoid high packet loss rate of the system caused by the system congestion. The FABA scheme then formulates the scheduling problem into a problem of overall system utility maximization. We solve the problem by using a heuristic algorithm with low computational complexity. The simulation results show that the proposed FABA scheme outperforms the existing algorithms in terms of the system throughput and the packet loss rate and can also guarantee the fairness demand among users.
基金supported by the National Natural Science Foundation of China (Grant No.60572156)
文摘MIMO-OFDMA is a promising technique for future broadband wireless communication systems. In this paper, the problem of allocating subcarriers among different users to maximize the total capacity is addressed. The optimal solution can be obtained by Hungarian method is proved, using two utility matrices, i.e. the Frobenius-norm matrix and the determinant matrix. Simulation results show that the proposed algorithm can achieve higher capacity than the existing algorithms, and it is globally optimal and easy to be implemented.
文摘Beamforming is a kind of signal processing technique which can improve system performance in the multiple-input multiple-output(MIMO)systems.In this paper,the problem of allocating subcarriers in MIMO-OFDMA wireless systems was analyzed,and a scheme to allocate subcarriers among all users based on beamforming was proposed to maximize the signal-to-noise ratio(SNR)at the receiver.Statistical properties of the channel matrix were studied,and some beneficial results were got.Statistical channel state information(CSI)was also taken into account to simulate more practical systems.Simulation results show that the proposed allocating scheme is effective,and it is robust to the influence of delayed CSI.
