Tengfei Xing

Resource Allocation for Layered Multicast Streaming in Wireless OFDMA Networks

In this paper, we focus on joint subchannel and power allocation for layered multicast streams in OFDMA cellular networks, where the multicast stream is composed of a basic layer and an enhancement layer. Our goal is to maximize the system total throughput with a total power constraint and a minimum rate requirement. A low-complexity allocation algorithm is proposed, which combined a cost-based subchannel allocation (CSA) with the traditional water filling (TWF) for base layer and an advanced water filling (AWF) for enhancement layer. A simplified advanced waterfilling (SWF) algorithm is also developed. Besides, we present a throughput condition-based user selection (TCUS) algorithm which selects a proper set of users to serve when the minimum rate requirement can not be satisfied. Numerical results show that our proposed algorithms improve the system throughput and outage probability over other algorithms.

Multidomain collaboration: A new framework of wireless networks with high transmission capacity

The bottleneck of wireless communication lies in the contradiction between limited spectrum resources and ever-increasing user demand. Multidomain collaboration (MDC) has emerged as a new framework to solve the problem, to some extent, with a great spectrum efficiency improvement. In this article, we introduce the concept of MDC with the help of some intuitive examples. Specifically, the underlying rationale of MDC for increasing transmission capacity is revealed from the perspective of both multiplexing gain and power gain. Cases studies of point-to-point, point-to-multipoint, multipoint-to-point, and multipoint-to-multipoint transmissions are conducted as preliminary evaluations of the performance limits that may be achieved by MDC.

A service-driven system architecture with Multi-Domain Collaboration for future wireless communications

In this article, we propose a service-driven architecture for wireless networks that incorporates the concept of multi-domain collaboration. This architecture inherits the physical infrastructure from existing cellular systems, while introducing a CS that configures the overlapped variable logical structure of the system according to service properties through a collaboration algorithm. Simulation results demonstrate that out framework can increase the system throughput up to 75% comparing with traditional cellular systems. Moreover, even if our theoretical analysis and simulations on the MDC architecture are based on single cell scenarios, they can also be applied to multi-cell cases by designing more sophisticated system architectures and algorithms following the same principles.

4-Transmit-Antenna STBC with 1 Bit Differential Feedback over Time-Selective Fading Channels

In this paper, a 4-transmit-antenna space time block coding (STBC) scheme with 1-bit differential feedback is proposed. This scheme gives full transmit diversity and spatial coding rate over time-selective fading channels by rotating the signal constellations for certain angles determined by the differential feedback information. By utilizing differential feedback, our method can provide much better channel orthogonality and track the variation of the channel more accurately and timely under time-selective fading circumstances, comparing to recent works presenting other quantized feedback schemes. Simulation results show that the 1-bit differential feedback scheme achieves near-optimum performance and outperforms existing algorithms without adding more overhead or complexity.

Improving transmission capacity of wireless networks with multi-domain collaborations

This paper provides a glimpse of ways to improve the transmission capacity of wireless networks by means of multi-domain collaboration, which is supposed to be a potential future framework of wireless communication under study supported by the national basic research program in China (973). It is shown that, for the cases of point-to-point, point-to-multipoint, multipoint-to-point and multipoint-to-multipoint, multi-domain collaboration amongst power domain, space domain, time domain as well as transmission points may yield quite improved capacity. Key technologies to accomplish multi-domain collaboration are also briefly addressed.