A Novel Multiple-Output DUSTF Coding on High Mobility MIMO-Wireless Communication Systems

In the future, wireless access system will operate in high data rate transmission and high mobility environment, to support private and public access. For such an environment, it is necessary to develop a system that has a higher spectrum efficiency and is able to mitigate selective fading problems. A novel multiple-output differential unitary space-time frequency (DUSTF) coding scheme is proposed to overcome those problems. The implementation of this inner coding scheme is unified with MIMO system, so that the scheme has a good spectrum efficiency. The differential space-time modulation in this proposed scheme is intended to operate in a non-coherent channel transmission scheme and to guarantee the system performance. In order to combat the selective fading problems, the multi-carrier space frequency scheme is utilized in the proposed scheme. In general, simulation result shows that the MIMO wireless system with the multiple-output DUSTF coding scheme in a non-coherent channel transmission scheme provides a good system performance. The proposed scheme can outperforms other previously published inner coding scheme for high mobility and high SNR. The system also achieves a good channel capacity

Performance Analysis with Coordination Among Base Stations for Next Generation Communication System

[[abstract]]Next generation communication system, such as Long Term Evolution Advanced (LTE-A), has the advantages of high transmission rate, wide bandwidth and better bandwidth utilization in high mobility environments. However, in such a kind of system when users are distributed sparsely in the base station coverage range the spectrum efficiency becomes worse. The emergence of new technologies such as the coordination among based stations makes the utilization of system bandwidth more efficient. The technology of coordination among base stations has other merits such as reducing noise interference, increasing receiving diversity, improving the system receiving gain, etc. In this paper, the system spectrum utilization and its associated efficiency will be investigated when the scheme of coordination among base stations is implemented.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]電子

Resource Allocation for Device-to-Device Communications in Multi-Cell Multi-Band Heterogeneous Cellular Networks

Heterogeneous cellular networks (HCNs) with millimeter wave (mm-wave) communications are considered as a promising technology for the fifth generation mobile networks. Mm-wave has the potential to provide multiple gigabit data rate due to the broad spectrum. Unfortunately, additional free space path loss is also caused by the high carrier frequency. On the other hand, mm-wave signals are sensitive to obstacles and more vulnerable to blocking effects. To address this issue, highly directional narrow beams are utilized in mm-wave networks. Additionally, device-to-device (D2D) users make full use of their proximity and share uplink spectrum resources in HCNs to increase the spectrum efficiency and network capacity. Towards the caused complex interferences, the combination of D2D-enabled HCNs with small cells densely deployed and mm-wave communications poses a big challenge to the resource allocation problems. In this paper, we formulate the optimization problem of D2D communication spectrum resource allocation among multiple micro-wave bands and multiple mm-wave bands in HCNs. Then, considering the totally different propagation conditions on the two bands, a heuristic algorithm is proposed to maximize the system transmission rate and approximate the solutions with sufficient accuracies. Compared with other practical schemes, we carry out extensive simulations with different system parameters, and demonstrate the superior performance of the proposed scheme. In addition, the optimality and complexity are simulated to further verify effectiveness and efficiency.Comment: 13 pages, 11 figures, IEEE Transactions on Vehicular Technolog