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2009 IEEE wireless communications and networking Conference, WCNC 2009

作者： Zhu, Yajun Sun, Zhenqiang Wang, Wei Peng, Tao Wang, Wenbo Wireless Signal Processing and Networking Lab Key Laboratory of Universal Wireless Communication Beijing University of Posts and Telecommunications Beijing China

ISBN: (纸本)9781424429486

In cognitive radio networks, the unlicensed users can utilize the unoccupied licensed spectrum opportunistically. In this paper, we propose a joint power and end-to-end rate control algorithm considering restricting the interference to licensed users. By duality theory, the optimal resource allocation solution is given for the unlicensed users while satisfying the interference temperature limits. An asynchronous algorithm is proposed to be implemented in practical networks. Finally, we give a discussion to the proposed algorithm's performance on fairness. Numerical results show that the proposed algorithm can limit the interference to licensed user under a predefined threshold while maintaining a satisfied data rate fairly. © 2009 IEEE.

关键词： Cognitive radio

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Route selection strategies in cellular networks with two-hop relaying

Route selection strategies in cellular networks with two-hop...

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5th International Conference on wireless communications, networking and Mobile Computing, WiCOM 2009

作者： Zhangchao, Ma Zheng, Kan Wang, Wenbo Liu, Yang Wireless Signal Processing Lab. Key Laboratory of Universal Wireless Communication Beijing China

ISBN: (纸本)9781424436934

In the relay enhanced cellular network (REC), user terminals can flexibly select transmission routes to get service. This paper investigated the effect of route selection schemes on the system performance of REC. Besides the traditional schemes based on signal power and signal-to-interference-plus-noise- ratio (SINR), we evaluated the effective spectral efficiency (SE) based approach which takes into account the feature of multihop transmission. We compared these three schemes through system level simulation, which is based on 3GPP LTE system enhanced with 2-hop fixed relay nodes. The results confirm that the SE-based scheme outperforms the other two schemes. Moreover, the results show that the effect of route selection heavily depends on the position of RNs. The REC system with signal power or SINR based route selection scheme yields even worse throughput than the non-relay case at certain positions. However, the SE-based scheme can always guarantee the gain from relaying. ©2009 IEEE.

关键词： Spectrum efficiency

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Performance analysis of amplify-and-forward relaying with hybrid-ARQ in Rayleigh fading channels

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The Journal of China Universities of Posts and Telecommunications 2009年第6期16卷 32-37页

作者： ZHENG Kan HU Li-jie GU Da-qing WANG Hai-la WANG Wen-bo Wireless Signal Processing and Network Lab Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China Orange R&D (Beijing) Beijing 100080 China

Hybrid automatic repeat request（HARQ） is a well-known technique for improving system throughput and link performance of wireless communication systems,including cooperative communication *** amplify-and-forward（AF） relaying method is one of the most attractive cooperative diversity schemes because of its low *** this article,the end-to-end performance in terms of block error rate（BLER） and normalized throughput of AF relaying with HARQ transmission under the Rayleigh fading channel is *** results validate the proposed analysis and demonstrate the gain of HARQ schemes in AF relaying *** analytical method can be extended to the systems with other HARQ protocols and other cooperative relaying schemes.

关键词： cooperative diversity AF HARQ BLER

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The performance analysis of multi-hop based broadcasting

The performance analysis of multi-hop based broadcasting

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2009 IEEE International Conference on communications Technology and Applications, IEEE ICCTA2009

作者： Dongyan, Wei Wenbo, Wang Mugen, Peng Wireless Signal Processing and Network Lab Key Laboratory of Universal Wireless Communication Beijing University of Posts and Telecommunications Beijing China

ISBN: (纸本)9781424448203

In the traditional broadcast system, the capacity is always limited by the users located at the edge of the coverage area, which degraded the experience of the users near the base station. In this paper, the broadcasting scheme based on multi-hop is proposed, and the outage performance of the proposed scheme is analyzed under both the Rayleigh and Nakagami-m channel. It is shown that, with the help of relays, the performance of the users at the edge of the coverage is promoted greatly. And the multi-hop scheme outperforms the traditional direct transmission scheme greatly with the increased number of relays, under the assumption that the nonadjacent relays have noninterference to each other. Another important conclusion is that the multi-hop scheme performs better than direct transmission under higher attenuation scenarios. ©2009 IEEE.

关键词： Transmissions

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Multi-service transmission in multiuser cooperative networks

Multi-service transmission in multiuser cooperative networks

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2009 IEEE wireless communications and networking Conference, WCNC 2009

作者： Yang, Chao Wang, Wenbo Zhang, Xing Beijing University of Posts and Telecommunications Wireless Signal Processing and Network Lab Key Laboratory of Universal Wireless Communication Beijing China

ISBN: (纸本)9781424429486

This paper analyzes the problem of multi-service transmission in multiuser cooperative networks. The objective is to maximize the Best Effort (BE) service utility while guaranteing the rate constraint of QoS service. In this paper, we first deduce the optimal power ratio of the source obtained power to total power. Based on this deduction result, the optimal solution of multi-service transmission is investigated. To further reduce the algorithm complexity, a suboptimal resource allocation algorithm is also proposed. Simulation results are provided to evaluate the utility and outage performance of these two algorithms when different value of power ratio is chosen. © 2009 IEEE.

关键词： Computational complexity

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Impacts of amplifier nonlinearities on uplink performance in 3G LTE systems

Impacts of amplifier nonlinearities on uplink performance in...

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2009 4th International Conference on communications and networking in China, CHINACOM 2009

作者： Zheng, Kan Wei, Meiying Long, Hang Liu, Yang Wang, Wenbo Wireless Signal Processing and Network Lab. Key Laboratory of Universal Wireless Communication Beijing University of Posts and Telecommunications Beijing 100088 China

ISBN: (纸本)9781424443376

As good candidates for uplink multiple access scheme in broadband wireless communication systems, orthogonal frequency division multiplexing (OFDM) and single-carrier (SC) with frequency division multiple access (FDMA) have gained enough attention recently. However, the non-linearity of amplifier deteriorates the performances of these two schemes. On the assumption of non-linear amplifier applied, we compare the block error rate (BLER) and throughput performances between SC-FDMA and OFDM schemes in the framework of third generation (3G) long-term evolution (LTE) systems, where the adaptive modulation and coding (AMC) technique with slow power control is used. Our simulation results show that the impacts of non-linearity on two schemes are different and dependent on several factors including the power gain of the amplifier.

关键词： Frequency division multiple access

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A multilevel Hopfield neural network for OFDM system with phase noise

A multilevel Hopfield neural network for OFDM system with ph...

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7th International Conference on Information, communications and signal processing, ICICS 2009

作者： Quan, Qingyi Wireless Signal Processing and Network Lab. Key Laboratory of Universal Wireless Communication Beijing University of Posts and Telecommunications Beijing 100876 China

ISBN: (纸本)9781424446575

Phase noise causes common phase error (CPE) and intercarrier interference (ICI) in orthogonal frequency division multiplexing (OFDM) system. To mitigate the effects of phase noise, many schemes have been proposed, but they are either computationally complex or at the price of sacrificing spectral efficiency. In this paper, a continuous Hopfield neural network (HNN) is designed for OFDM signal receiver as a component to mitigate the effects of phase noise. This component does not require any special assistance from transmitter side, but it should be used in conjunction with phase noise matrix estimation. HNN, through self-evolution, performances likelihood test with possible symbols, and outputs a symbol for which the likelihood function has a relatively large value. The performance of the proposed HNN based detection is evaluated via computer simulations and compared to both the conventional detection and a single carrier system. It is shown that the HNN based detection can significantly improve the bit error rate (BER) performance in the presence of phase noise. ©2009 IEEE.

关键词： Orthogonal frequency division multiplexing

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Distributed power control for OFDMA based spatial multiplexing multi-hop systems

Distributed power control for OFDMA based spatial multiplexi...

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2009 3rd IEEE International Symposium on Microwave, Antenna, Propagation and EMC Technologies for wireless communications, MAPE 2009

作者： Fan, Bin Wang, Wenbo Lin, Yicheng Zheng, Kan Wireless Signal Processing and Network Lab Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing China

ISBN: (纸本)9781424440740

In this paper, a distributed power control algorithm is proposed to perform adaptive spatial multiplexing for the relay enhanced orthogonal frequency division multiple access (OFDMA) cellular systems. As the optimal spatial multiplexing problem is non-convex, we utilize the distributed iteration method to achieve its near-optimal solution. By determining the restriction on the transmit power for each subcarrier, the individual power allocation at the base station (BS) and the relay station (RS) can always converge to some desirable Nash Equilibriums with satisfying performance. Simulation results show that the proposed distributed power control algorithm provides significant gain in system transmit rate over the traditional iterative waterfilling scheme. ©2009 IEEE.

关键词： Frequency division multiple access

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A novel data stream selection algorithm for S-PARC in TD-SCDMA HSPA+ system

A novel data stream selection algorithm for S-PARC in TD-SCD...

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2009 IEEE International Conference on communications Technology and Applications, IEEE ICCTA2009

作者： Zhang, Xiang Ji, Xiaodong Li, Yong Peng, Mugen Wang, Wenbo Wireless Signal Processing and Network Laboratory Key Laboratory of Universal Wireless Communication Beijing University of Posts and Telecommunications Beijing 100876 China

ISBN: (纸本)9781424448203

Selective per antenna rate control (S-PARC) technique has been decided to be deployed in time division-synchronous code division multiple access (TD-SCDMA) high speed packet access plus (HSPA+) system. In this paper, we propose an enhanced data stream selection algorithm for the proposal of S-PARC to improve Node B average throughput and initial block error rate (BLER) by pre-processing signal to interference plus noise ratio (SINR). The new algorithm considers the impact of channel fluctuation, Node B average initial BLER and continue scheduling of the same UE. It is shown that the proposed scheme can achieve remarkable improvement of system performance, especially when UE is under high speed mode, and it also has advantages in the following ways: little modification for current specification, low computational complexity and no additional controlling signals. ©2009 IEEE.

关键词： Beamforming

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System-level evaluation of MIMO performance in TD-HSPA+ system

System-level evaluation of MIMO performance in TD-HSPA+ syst...

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2009 IEEE International Conference on communications Technology and Applications, IEEE ICCTA2009

作者： Hu, Chunjing Li, Yong Peng, Mugen Wang, Wenbo Wireless Signal Processing and Network Laboratory Key Laboratory of Universal Wireless Communication Beijing University of Posts and Telecommunications Beijing 100876 China

ISBN: (纸本)9781424448203

Similar to its frequency division duplex (FDD) counterpart, there is currently great interest in introducing multiple-input multiple-output (MIMO) antenna technique into time division-synchronized code division multiple access (TD-SCDMA) high-speed packet access evolution (HSPA+) system within 3GPP. To this end, per-antenna rate control (PARC), selective-PARC (S-PARC) and dual-stream transmit antenna array (D-TxAA) are three candidate MIMO schemes. System-level evaluation for these MIMO schemes is significant for the finalization of TD-SCDMA HSPA+ standardization roadmap. Specifically, a new interface between link-level simulation and system-level simulation is required to model accurately MIMO link behavior in a system-level simulator. In this paper, we first elaborate the new simulation interface used in our simulator, and then present the performance results of these three MIMO schemes. It's shown that S-PARC can provide relatively high throughput and has low requirement on feedback overhead;therefore, it deserves more attention in TD-SCDMA HSPA+ standardization work. ©2009 IEEE.

关键词： Code division multiple access

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