This article considers the two-way multiple-input multiple-output（MIMO） relaying channels with multiple users,in which multiple users are served simultaneously by the base station（BS） with the assistance of the re...This article considers the two-way multiple-input multiple-output（MIMO） relaying channels with multiple users,in which multiple users are served simultaneously by the base station（BS） with the assistance of the relay.The transmission consists of only two phases,doubling the system throughout over traditional one-way half-duplex transmission.A zero-forcing dirty paper coding（ZFDPC） aided physical-layer network coding（PNC） scheme is proposed in this article and the achievable capacity of the ZFDPC aided PNC scheme is derived.Simulation results show that the proposed scheme outperforms the previous decode-and-forward（DF） and zero-forcing beamforming（ZFBF） aided PNC scheme due to more degrees of freedoms and the advantage of PNC.Moreover,we analyze the effect of the imperfect channel state information（CSI） from RS to users at BS side to show the robustness of the proposed ZFDPC aided PNC scheme.展开更多
In this paper, a network scenario of two-way relaying over orthogonal frequency division multiplexing （OFDM） is considered, in which two nodes intend to exchange the information via a relay using physical-layer netw...In this paper, a network scenario of two-way relaying over orthogonal frequency division multiplexing （OFDM） is considered, in which two nodes intend to exchange the information via a relay using physical-layer network coding （PLNC）. Assuming that the full channel knowledge is available, an optimization problem, which maximizes the achievable sum rate under a sum-power constraint, is investigated. It is shown that the optimization problem is non-convex, which is difficult to find the global optimum solution in terms of the computational complexity. In consequence, a low-complexity optimal power allocation scheme is proposed for practice implementation. A link capacity diagram is first employed for power allocation on each subcarrier. Subsequently, an equivalent relaxed optimization problem and Karush-Kuhn-Tucker （KKT） conditions are developed for power allocation among each subcarrier. Simulation results demonstrate that the substantial capacity gains are achieved by implementing the proposed schemes efficiently with a low-complexity computational effort.展开更多
This paper investigates the performance of a two-way amplify-and-forward （AF） relay system with adaptive modulation over independent and non-identical Nakagami-m fading channels. The tight closed-form cumulative dis...This paper investigates the performance of a two-way amplify-and-forward （AF） relay system with adaptive modulation over independent and non-identical Nakagami-m fading channels. The tight closed-form cumulative distribution function （CDF） expression of the instantaneous end-to-end signal-to-noise ratio （SNR） is provided. Further, approximate closed-form expression for the average spectral efficiency of the two-way AF system with adaptive modulation is obtained. Then, a tight lower bound of outage probability is derived. Finally, we use numerical simulations to verify the tightness of our analytical results.展开更多
In this paper, a joint precoding and decoding design scheme is proposed for two-way Multiple-Input Multiple-Output (MIMO) multiple-relay system. The precoding and decoding matrices are jointly optimized based on Minim...In this paper, a joint precoding and decoding design scheme is proposed for two-way Multiple-Input Multiple-Output (MIMO) multiple-relay system. The precoding and decoding matrices are jointly optimized based on Minimum Mean-Square-Error (MMSE) criteria under transmit power constraints. The optimization problem is solved by using a convergent iterative algorithm which in-cludes four sub-problems. It is shown that due to the difficulty of the block diagonal nature of the relay precoding matrix, sub-problem two cannot be solved with existing methods. It is then solved by converting sub-problem two into a convex optimization problem and a simplified method is proposed to reduce the computational complexity. Simulation results show that the proposed scheme can achieve lower Bit Error Rate (BER) and larger sum rate than other schemes. Furthermore, the BER and the sum rate performance can be improved by increasing the number of antennas for the same number of relays or increasing the number of relays for the same number of antennas.展开更多
基金supported by IMT-Advanced Novel Wireless Transmission Technology Program (2008ZX03003-004,2008BAH30B09)Chinese Important National Science and Technology Specific Project (2010ZX03002-003)+1 种基金the National Basic Research Program of China (2007CB310602)International Science and Technology Cooperation Program (2008DFA12160)
文摘This article considers the two-way multiple-input multiple-output（MIMO） relaying channels with multiple users,in which multiple users are served simultaneously by the base station（BS） with the assistance of the relay.The transmission consists of only two phases,doubling the system throughout over traditional one-way half-duplex transmission.A zero-forcing dirty paper coding（ZFDPC） aided physical-layer network coding（PNC） scheme is proposed in this article and the achievable capacity of the ZFDPC aided PNC scheme is derived.Simulation results show that the proposed scheme outperforms the previous decode-and-forward（DF） and zero-forcing beamforming（ZFBF） aided PNC scheme due to more degrees of freedoms and the advantage of PNC.Moreover,we analyze the effect of the imperfect channel state information（CSI） from RS to users at BS side to show the robustness of the proposed ZFDPC aided PNC scheme.
基金supported by the National Natural Science Foundation of China (60496315,60802009)the Hi-Tech Research and Development Program of China (2008AA01Z204,2009AA011202,2009AA01Z205)the International Science and Technology Cooperation Programmer of China (2008DFA11630)
文摘In this paper, a network scenario of two-way relaying over orthogonal frequency division multiplexing （OFDM） is considered, in which two nodes intend to exchange the information via a relay using physical-layer network coding （PLNC）. Assuming that the full channel knowledge is available, an optimization problem, which maximizes the achievable sum rate under a sum-power constraint, is investigated. It is shown that the optimization problem is non-convex, which is difficult to find the global optimum solution in terms of the computational complexity. In consequence, a low-complexity optimal power allocation scheme is proposed for practice implementation. A link capacity diagram is first employed for power allocation on each subcarrier. Subsequently, an equivalent relaxed optimization problem and Karush-Kuhn-Tucker （KKT） conditions are developed for power allocation among each subcarrier. Simulation results demonstrate that the substantial capacity gains are achieved by implementing the proposed schemes efficiently with a low-complexity computational effort.
基金supported by the China's Major Projects on Science and Technology for New-Generation Broadband Wireless Mobile Communications Network (2010ZX03001-001-03)
文摘This paper investigates the performance of a two-way amplify-and-forward （AF） relay system with adaptive modulation over independent and non-identical Nakagami-m fading channels. The tight closed-form cumulative distribution function （CDF） expression of the instantaneous end-to-end signal-to-noise ratio （SNR） is provided. Further, approximate closed-form expression for the average spectral efficiency of the two-way AF system with adaptive modulation is obtained. Then, a tight lower bound of outage probability is derived. Finally, we use numerical simulations to verify the tightness of our analytical results.
基金Supported by the National Science and Technology Specific Project (2011ZX03005-004-003)the National Natural Science Foundation of China (No. 61071090, 61171093)+2 种基金973 Project of Jiangsu Province (BK2011027)the Project 11KJA510001 and PAPDthe Jiangsu Postgraduate Research Project (CXZZ11_0384)
文摘In this paper, a joint precoding and decoding design scheme is proposed for two-way Multiple-Input Multiple-Output (MIMO) multiple-relay system. The precoding and decoding matrices are jointly optimized based on Minimum Mean-Square-Error (MMSE) criteria under transmit power constraints. The optimization problem is solved by using a convergent iterative algorithm which in-cludes four sub-problems. It is shown that due to the difficulty of the block diagonal nature of the relay precoding matrix, sub-problem two cannot be solved with existing methods. It is then solved by converting sub-problem two into a convex optimization problem and a simplified method is proposed to reduce the computational complexity. Simulation results show that the proposed scheme can achieve lower Bit Error Rate (BER) and larger sum rate than other schemes. Furthermore, the BER and the sum rate performance can be improved by increasing the number of antennas for the same number of relays or increasing the number of relays for the same number of antennas.
