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Feng B.,Beijing University of Posts and Telecommunications | Li G.,Key Laboratory of Universal Wireless Communication
Proceedings - 2012 International Conference on Computer Science and Information Processing, CSIP 2012 | Year: 2012

This paper raises a low-overhead LTE-Advanced relay network handover scheme. When relay involved in the LTE-Advanced cellular network, handover scenario and process will become more complicated. We consider two-hop relay network, the backhaul hop (BS-RS hop) resource is very precious and become a bottleneck of LTE-Advanced network performance. Directly using traditional handover scheme in relay network will bring in a lot of backhaul signaling. So a new handover scheme is raised. The scheme concentrates on reducing signaling cost while ensure users' QoS. © 2012 IEEE. Source

Peng M.,Key Laboratory of Universal Wireless Communication | Wang W.,BUPT | Chen H.-H.,National Cheng Kung University
IEEE Vehicular Technology Magazine | Year: 2010

This article focuses on the evolutional strategies (which can be divided into four phases) from the current commercial time division-synchronous code division multiple access (TD-SCDMA) to the future International Mobile Telecommunications (IMT)-Advanced systems. The first evolutional phase is to develop an N-frequency technology to improve capacity and ease network planning of the current TD-SCDMA system. Single- and multicarrier high-speed packet access (HSPA) is specified in the second phase for providing high-rate packet services. Long-term evolution (LTE) technology is introduced in the third phase to provide a similar performance of mobile worldwide interoperability for microwave access (WiMAX). Finally, the fourth phase is to implement time division duplex (TDD)-based IMT-Advanced system, which is one of the alternative standards beyond third-generation (3G) systems. The advanced technologies to enhance spectral efficiency are the critical issues emphasized in all the four phases. The challenges and open issues in the different evolutional phases are identified in this article as well. © 2006 IEEE. Source

Xu W.,Beijing University of Posts and Telecommunications | Zhang J.,Key Laboratory of Universal Wireless Communication | Zhang P.,Key Laboratory of Universal Wireless Communication
Electronics Letters | Year: 2010

The performance of a dual-hop amplify-and-forward relay system, which experiences mixed Nakagami-m and Rician fading channels, is investigated. Based on the closed-form cumulative probability density function of the equivalent end-to-end signal-to-noise ratio, the exact expressions for outage probability and average symbol error probability are derived. The theoretical observations are verified by the Monte Carlo simulation results. © 2010 The Institution of Engineering and Technology. Source

Qian R.,Beijing University of Posts and Telecommunications | Peng T.,Key Laboratory of Universal Wireless Communication | Wang W.,Key Laboratory of Universal Wireless Communication | Yang J.,Beijing University of Posts and Telecommunications
Signal Processing | Year: 2013

In this paper, the insight into the scale effects oriented MIMO detector (SEOD) which is developed for the MIMO system that has to detect signals of multiple users, e.g., the multiple-antenna base-station (BS) system, is presented. The diversity order, complexity and scale effects of SEOD are investigated. The main contributions of this work can be listed as follows: (1) applying the concept of scale effects in microeconomics to MIMO detection and establishing the corresponding model for the analysis of scale effects; (2) presenting the complete proof of the existence of scale effects in our proposed SEOD scheme; (3) demonstrating that the scale effects can be utilized to realize MIMO detection that has the optimal performance in the sense of diversity order while keeping the worst-case unit complexity be polynomial in multiple-user system. Through the computer simulation, we obtain the numerical results which support the theoretical analysis. © 2012 Elsevier B.V. Source

Wang T.,Key Laboratory of Universal Wireless Communication | Wang Y.,Key Laboratory of Universal Wireless Communication
2011 IEEE GLOBECOM Workshops, GC Wkshps 2011 | Year: 2011

From the view of radio resource management, many literatures for distributed antenna systems (DAS) focus on the joint precoding design and related optimal power allocation (PA), which is a narrowband case. The joint resource allocation in broadband orthogonal frequency division multiple access DAS (OFDMA-DAS) has not been thoroughly studied, which includes the distributed antenna port selection, subcarrier assignment and PA under the power constraint per antenna port. This paper focuses on the downlink resource allocation in OFDMA-DAS. The coherent transmitter with phase steering is used. The problem to maximize the system spectrum efficiency (SE) is formulated, and solved by the dual decomposition method, where the decomposed subproblems in the dual domain are solved from the perspective of analytic geometry. Next, a suboptimal algorithm is developed. From the analysis of per subcarrier transmission, it is found that a proportional PA (PPA) method can achieve a local SE optimality for an individual subcarrier. By applying the PPA, the original problem is transformed into a new form and can be solved similarly. Numerical results show that the optimal algorithm has good convergence. The suboptimal algorithm can save a considerable part of system power while achieving the SE optimality, thanks to the distributed feature in DAS. © 2011 IEEE. Source

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