Different from conventional cellular networks, a maritime communication base station(BS) has to cover a much wider area due to the limitation of available BS sites. Accordingly the performance of users far away from t...Different from conventional cellular networks, a maritime communication base station(BS) has to cover a much wider area due to the limitation of available BS sites. Accordingly the performance of users far away from the BS is poor in general. This renders the fairness among users a challenging issue for maritime communications. In this paper, we consider a practical massive MIMO maritime BS with hybrid digital and analog precoding. Only the large-scale channel state information at the transmitter(CSIT) is considered so as to reduce the implementation complexity and overhead of the system. On this basis, we address the problem of fairness-oriented precoding design. A max-min optimization problem is formulated and solved in an iterative way. Simulation results demonstrate that the proposed scheme performs much better than conventional hybrid precoding algorithms in terms of minimum achievable rate of all the users, for the typical three-ray maritime channel model.展开更多
We provide a broad look at the field of limited feedback in wireless communication.We review works of limited feedback with various combinations of single antenna,multiple antenna,single-user and multiuser technology ...We provide a broad look at the field of limited feedback in wireless communication.We review works of limited feedback with various combinations of single antenna,multiple antenna,single-user and multiuser technology and provide a synopsis of the role of limited feedback in wireless communication systems.We also study how the feedback rate can be minimized without losing the gains due to adaptive transmission and multiuser diversity.It seems that the best possible feedback scheme is not invented yet.As another conclusion is that there are still many issues to study before the scheme can be used in practice.展开更多
The channel state information at transmitter （CSIT） acquisition plays a key role in the multi-input multi-output （MIMO） system, especially for the precoding schemes. However it is unrealizable to acquire perfect C...The channel state information at transmitter （CSIT） acquisition plays a key role in the multi-input multi-output （MIMO） system, especially for the precoding schemes. However it is unrealizable to acquire perfect CSIT in practice. In this article, an effective and practical dynamic CSIT model is introduced to acquire imperfect channel state information. For practicability, the channel temporal and spatial correlations are considered and the channel estimate and its error covariance are obtained by utilizing the outdated channel state information. Based on the dynamic CSIT mode, closed-form solution of robust Tomlinsion-Harashima precoding （THP） is derived by a Lagrangian approach. Numerical simulations are presented to demonstrate the performance.展开更多
基金supported in part by the National Science Foundation of China under grant No. 91638205,grant No. 61771286, and grant No. 61701457, and grant No. 61621091
文摘Different from conventional cellular networks, a maritime communication base station(BS) has to cover a much wider area due to the limitation of available BS sites. Accordingly the performance of users far away from the BS is poor in general. This renders the fairness among users a challenging issue for maritime communications. In this paper, we consider a practical massive MIMO maritime BS with hybrid digital and analog precoding. Only the large-scale channel state information at the transmitter(CSIT) is considered so as to reduce the implementation complexity and overhead of the system. On this basis, we address the problem of fairness-oriented precoding design. A max-min optimization problem is formulated and solved in an iterative way. Simulation results demonstrate that the proposed scheme performs much better than conventional hybrid precoding algorithms in terms of minimum achievable rate of all the users, for the typical three-ray maritime channel model.
基金supported by the National Natural Science Foundation of China (No. 60972041, 60572130)Natural Science Fundamental Research Pro-gram of Jiangsu Universities (No. 08KJD510001)+4 种基金PH. D. Program Foundation of Ministry of Education (No. 20080293004)National Special Project(2009ZX03003-006)National Basic Research Program of China (No. 2007CB310607)Graduate Innovation Program (No.CX09B-146Z)the pro-ject of NJUPT (NY206061)
文摘We provide a broad look at the field of limited feedback in wireless communication.We review works of limited feedback with various combinations of single antenna,multiple antenna,single-user and multiuser technology and provide a synopsis of the role of limited feedback in wireless communication systems.We also study how the feedback rate can be minimized without losing the gains due to adaptive transmission and multiuser diversity.It seems that the best possible feedback scheme is not invented yet.As another conclusion is that there are still many issues to study before the scheme can be used in practice.
基金supported by the National Basic Research Program of China (2007CB310604,2009CB320401)the National Natural Science Foundation of China (60772108,60702048)
文摘The channel state information at transmitter （CSIT） acquisition plays a key role in the multi-input multi-output （MIMO） system, especially for the precoding schemes. However it is unrealizable to acquire perfect CSIT in practice. In this article, an effective and practical dynamic CSIT model is introduced to acquire imperfect channel state information. For practicability, the channel temporal and spatial correlations are considered and the channel estimate and its error covariance are obtained by utilizing the outdated channel state information. Based on the dynamic CSIT mode, closed-form solution of robust Tomlinsion-Harashima precoding （THP） is derived by a Lagrangian approach. Numerical simulations are presented to demonstrate the performance.
