Li F.,Key Laboratory of Universal Wireless Communication |
Zhao L.,Key Laboratory of Universal Wireless Communication |
Zheng K.,Key Laboratory of Universal Wireless Communication |
Wang J.,Key Laboratory of Universal Wireless Communication
2016 IEEE Globecom Workshops, GC Wkshps 2016 - Proceedings | Year: 2016
This paper proposes a new generalized frequency division multiplexing (GFDM) transmission scheme. The orthogonality conditions are first proposed in order to eliminate the intrinsic interference of the conventional GFDM system. Based on the orthogonality conditions, two prototype filters are then designed for the new GFDM scheme, and are used for the evennumbered subcarriers and odd-numbered subcarriers, respectively. So, the even-numbered subcarriers and odd-numbered subcarriers can reach orthogonality, and then can get rid of the intrinsic interference. Simulation results indicate that the proposed GFDM scheme has the same bit error rate (BER) performance to the orthogonal frequency division multiplexing system, and the BER performs better than that of the conventional GFDM system. Moreover, the conventional multiple-input multiple-output transmission schemes and channel estimation schemes can be directly applied on the proposed GFDM system. © 2016 IEEE.
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.
Yang S.,Beijing University of Posts and Telecommunications |
Can Z.,Key Laboratory of Universal Wireless Communication
Proceedings of the 2014 9th International Conference on Communications and Networking in China, CHINACOM 2014 | Year: 2015
Multiple antenna channel emulator is often utilized to emulate in the laboratory and in real time the highly dispersive propagation conditions of the mobile radio channels. This paper presents the design of a real time multiple channel emulator for LTE system which is implemented in a modular way. This emulator allows us to emulate the effects of the multiple-input-multiple-output(MIMO) and propagation environments in LTE system. This emulator provides guidelines for both the procedures and the criteria to be used in evaluating the proposed LTE radio interface technologies for a number of test environments and deployment scenarios. © 2014 IEEE.
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.
Mao S.,Key Laboratory of Universal Wireless Communication |
Mao S.,Beijing University of Posts and Telecommunications |
Zhao C.,Key Laboratory of Universal Wireless Communication |
Zhao C.,Beijing University of Posts and Telecommunications |
And 3 more authors.
Mobile Networks and Applications | Year: 2013
This paper introduces IFUC, which is an Improved Fuzzy Unequal Clustering scheme for large scale wireless sensor networks (WSNs).It aims to balance the energy consumption and prolong the network lifetime. Our approach focuses on energy efficient clustering scheme and inter-cluster routing protocol. On the one hand, considering each node's local information such as energy level, distance to base station and local density, we use fuzzy logic system to determine each node's chance of becoming cluster head and estimate the cluster head competence radius. On the other hand, we use Ant Colony Optimization (ACO) method to construct the energy-aware routing between cluster heads and base station. It reduces and balances the energy consumption of cluster heads and solves the hot spots problem that occurs in multi-hop WSN routing protocol to a large extent. The validation experiment results have indicated that the proposed clustering scheme performs much better than many other methods such as LEACH, CHEF and EEUC. © 2012 Springer Science+Business Media, LLC.
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.
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.
Zhao L.,Key Laboratory of Universal Wireless Communication |
Zhao H.,Key Laboratory of Universal Wireless Communication |
Zheng K.,Key Laboratory of Universal Wireless Communication |
Yang Y.,Key Laboratory of Universal Wireless Communication
IEEE International Conference on Communications | Year: 2012
With the tremendous growth in wireless networks market, unprecedented energy consumption and emissions of carbon dioxide (CO2) is a growing concern for both operators and governments. OFDM technology has been adopted by many standards organizations due to its high spectrum efficiency, but induces poor energy efficiency of power amplifier (PA). A new scheme named Selecting Sub-Carriers Modulation (SSCM) to lower the input power of PA is given in this paper. SSCM divides the information bits into two parts of bits according to modulation mode: the first part of bits selects some sub-carriers of OFDM to transmit nothing, another part of bits is transmitted by the remainder sub-carriers. Sub-carriers transmitting nothing do not need energy, and fewer number of sub-carriers transmitting modulation symbols can improve PA's efficiency because of the lower peak-to-average power ratio (PAPR). Analysis results show SSCM with different modulation modes can lower input power of PA with different proportion compared with traditional OFDM. Theoretical analysis and simulation results of the reliability of SSCM are given and match closely. In multi-path channel, SSCM with BPSK has the same performance as BPSK in traditional OFDM, while SSCM with QPSK performs worse than QPSK in traditional OFDM. © 2012 IEEE.
Zhai S.,Key Laboratory of Universal Wireless Communication |
Jiang T.,Key Laboratory of Universal Wireless Communication |
Huang J.,Key Laboratory of Universal Wireless Communication
Proceedings - IEEE Military Communications Conference MILCOM | Year: 2013
In this paper, a novel sparse representation (SR) based method for recognizing targets under different foliage scenarios is presented. Target echo signals of different targets in different scenarios measured by bistatic ultra-wideband (UWB) radar are used for scenarios and targets recognition. Particularly, two overcomplete dictionaries one for scenarios and one for targets are learned from measured real target echo signal waveforms via dictionary learning technique. The SR expresses an input signal as the linear combination of a small number of the learned dictionary elements, which are from the same category as the input signal. The SR of a test target echo signal can be achieved by solving an L0-norm minimization problem. For targets recognition under multi-scenario, firstly, we locate the scenario of the targets with the overcomplete dictionary for scenarios via SR. Then, the types of the targets are recognized using the overcomplete dictionary for targets via SR. The effectiveness of the proposed approach is verified by experiments taken in the forest measurement. Experimental results on real measured data show that the proposed method achieves higher recognition accuracy. © 2013 IEEE.
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.