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3rd International Conference on Mobile Ad-Hoc and Sensor Networks

作者： Guo, Li-li Yue, Dian-wu Dalian Maritime Univ Coll Informat Engn Dalian 116026 Liaoning Peoples R China

ISBN: (纸本)9783540770237

Cooperative transmission breaks away from traditional transmission which only has single transmitter and single receiver in wireless networks, which enable single antenna mobiles in a multi-user environment to share their antennas and generate a virtual multiple-antenna transmitter in order to achieve transmit diversity. space-time block coding (STBC) is an attractive transmission diversity technique because of its linear complexity. Furthermore, signal space diversity can increase the diversity order through interleaving over coordinates and choosing a proper signal constellation. In this paper, cooperative transmissions for wireless sensor networks are considered. In order to improve the system performance, a new cooperative transmission scheme without perfect synchronization using both signal space diversity and STBC is proposed. It is shown by simulation that compared to the traditional transmission scheme with signal space diversity and the STBC-encoded cooperative transmission scheme without signal space diversity, the new scheme can provide further performance improvement by increasing the diversity order, and can save more energy in wireless sensor networks.

关键词： cooperative transmission wireless sensor network signal-space diversity space-time block code

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Application of cooperative diversity in 802.11a ad-hoc networks

Application of cooperative diversity in 802.11a ad-hoc netwo...

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16th International Conference on Computer Communications and Networks

作者： Zhao, Zhipeng Belfiore, Jean-Claude Ecole Natl Super Telecommun Bretagne Dept Commun & Elect 46 Rue Barrault F-75013 Paris France Ecole Nat Sup Telecom F-75013 Paris France COMSIS SAS F-75014 Paris France

ISBN: (纸本)9781424412501

In this paper, we propose an application of cooperative system in the ad-hoc network. Based on 802.11a PHY, a compatible physical layer protocol Relay-SISO is introduced for the single-relay single-antenna system. Using Non-orthogonal Amplify-and-Forward scheme, the proposed protocol boosts quality of transmission while works at the same data rate as 802.11a with little additional preambles. Simulation results reveal the feasibility of such cooperative scheme and a significant coding gain is observed at data rate 12Mbps.

关键词： cooperative diversity non-orthogonal amplify and forward multiple-input multiple-output space-time block code diversity-multiplexing tradeoff

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Efficient ISI cancellation for STBC, OFDM systems using successive interference cancellation

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IEEE COMMUNICATIONS LETTERS 2006年第8期10卷 629-631页

作者： Lee, Jong-Ho Kim, Seong-Cheol Samsung Elect Co Ltd Next Generat Syst Team Suwon South Korea Seoul Natl Univ Sch Elect Engn & Comp Sci Inst New Media & Commun Seoul 151742 South Korea

In this letter, we propose an efficient detection scheme for space-time block coded (STBC) orthogonal frequency-division multiplexing (OFDM) with insufficient cyclic prefix (CP). The proposed scheme employs successive interference cancellation (SIC) and cyclic prefix reconstruction (CPR) concepts. Simulation results present that the proposed scheme outperforms the conventional scheme for STBC OFDM systems.

关键词： orthogonl frequency-division multiplexing space-time block code successive interference cancellation cyclic prefix reconstruction

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On beamforming for space-time block coded OFDM systems in multipath fading channels

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IEICE TRANSACTIONS ON COMMUNICATIONS 2005年第3期E88B卷 1182-1190页

作者： Lee, SM Yoon, BH Choi, HJ ETRI Mobile Telecom Res Lab Taejon South Korea

Recently, in order to improve high speed data transmission and spectral efficiency in wireless communication systems, the combination of OFDM and space-time coding is being actively studied. In order to maximize the system efficiency, the problem of co-channel interference must be solved. One technique to overcome the co-channel interference and to increase the system capacity is to use adaptive antennas. Conventional beamforming techniques for single antenna cannot be applied directly to STBC-OFDM systems, because the signals transmitted from the two transmit antennas are superposed at the receive antenna and the interference between signals of the two transmit antennas occurs. In this paper, we present the MMSE beamforming technique using training sequence for STBC-OFDM systems in reverse link and evaluate the performance by using various parameters such as the number of training blocks, cluster sizes and angle spreads in, Two-ray, TU and HT channels. From the simulation results, we show the best cluster sizes and the number of training blocks corresponding to these cluster sizes.

关键词： beamforming MMSE OFDM transmit diversity space-time block code

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Optimization of space-time block codes based on multidimensional super-set partitioning

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IEEE SIGNAL PROCESSING LETTERS 2005年第4期12卷 317-320页

作者： Li, YH Vucetic, B Univ Sydney Sch Elect & Informat Engn Sydney NSW 2006 Australia

This letter presents an optimized space-time block code constructed by using multidimensional super-set partitioning (STBC-MDSP). The theoretical upper bound on the pairwise probability of STBC-MDSP is derived, and based on it, a code design criterion is proposed. It is shown that to optimize the performance of STBC-MDSP, one should maximize the sum square distance (SSD) in each level of super-set partitioning. Simulation results show that the proposed scheme is superior by about 2.5 and 1.5 dB to the Alamouti scheme and Tarokh-Seshadri-Calderbank (TSC) code with the same number of states, respectively, at the frame error rate (FER) of 10(-2) over quasi-static fading channels.

关键词： space-time block code super-set partitioning

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A comparison of orthogonal and quasi-orthogonal space-time block codes for fast fading channels

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IEICE TRANSACTIONS ON COMMUNICATIONS 2005年第7期E88B卷 3069-3072页

作者： Kim, J Cho, YS SAIT Commun & Network Lab Kyunggido South Korea Chung Ang Univ Sch Elect & Elect Engn Seoul 156756 South Korea

This letter compares orthogonal space time codes and quasi-orthogonal codes when the wireless channels are fast fading. It is well known that a orthogonal space-time code is better than a quasi-orthogonal code in high signal-to-noise ratio (SNR) range and that a quasi-orthogonal code is better in low SNR range. In this letter, we show that a quasi-orthogonal space-time code is a better choice even in high SNR range when the channels are fast fading.

关键词： space-time block code MIMO transmit diversity fast fading

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An adaptive power allocation scheme for space-time block coded MIMO systems

An adaptive power allocation scheme for space-time block cod...

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IEEE Wireless Communications and Networking Conference

作者： Xian, L Liu, HP Oregon State Univ Sch Elect Engn & Comp Sci Corvallis OR 97331 USA

ISBN: (纸本)0780389662

Receive diversity yields a higher signal-to-noise ratio (SNR) than transmit diversity when the total transmitted power and diversity order are the same. However, if the transmitter has complete or partial knowledge of channel, the SNR gap between these two schemes can be reduced. This paper introduces an adaptive power allocation scheme for space-time block coded (STBC) multiple-antenna systems to improve system performance. For any set of channel fading coefficients, the transmit power scaling factors are controlled by a single design parameter u. The proposed adaptive power allocation scheme improves the instantaneous SNR at the receiver. Special choices of U result in some existing STBC schemes. Performance gain of the proposed scheme over the conventional equal-power scheme under the condition of perfect and imperfect feedback is studied. The maximum achievable SNR gain limit over the conventional scheme is also derived.

关键词： error statistics space-time codes block codes MIMO systems power control adaptive control feedback diversity reception fading channels transmitting antennas receiving antennas adaptive power allocation space-time block code receive diversity signal-to-noise ratio transmit diversity perfect feedback imperfect feedback maximum achievable SNR gain STBC multiple-antenna systems system performance channel fading coefficients transmit power scaling factors instantaneous SNR multiple input multiple output systems diversity reception adaptive power allocation receive diversity transmitting antennas Receiving antennas space-time codes System performance block codes space time block coding Fading channels Power control adaptive control Feedback Transmitter power

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Improved algorithm of space-time block code for DSP implementation 6

Improved algorithm of Space-Time Block Code for DSP implemen...

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6th International Conference on Signal Processing

作者： Ge, YS Zhao, YX Tianjin Univ Sch Elect Informat Engn Tianjin 300072 Peoples R China

ISBN: (纸本)0780374886

This paper Presents an improved, low power algorithm for the DSP implementation of space-time block codes(STBC) using the previous reported maximum likelihood algorithm [3]. The new algorithm arrives at the same. decision with less computation and reduces power dissipation It is easily to using this algorithm in low-rank STBC and hopeful in high-rank STBC for an actual DSP. Based on the Tarokh's algorithm, a more efficient algorithm is developed by utilizing the properties of the constellation signals and decision matrices. In most cases, the new algorithm results in more than 30% reduction in the computation complexity.

关键词： space-time block code DSP wireless communication

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Improved channel estimation for OFDM systems with multiple transmit antennas over time-varying multipath fading channels

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IEICE TRANSACTIONS ON COMMUNICATIONS 2005年第5期E88B卷 2093-2101页

作者： Won, HC Im, GH Pohang Univ Sci & Technol Commun Res Lab Pohang 790784 South Korea

By using multiple transmit antennas, wireless systems have a large capacity in time-varying multipath fading channels. space-time block code (STBC), space-frequency block code (SFBC), and space-time-frequency (STF) block code are well-known techniques in transmitter diversity schemes. While the SFBC (or the STF block coded) system gives full diversity at frequency-nonselective channels, it breaks down when used in a frequency-selective environment. This is because the SFBC (or the STF block code) scheme disregards frequency selectivity of the channel by assuming that channel frequency responses (CFRs) at adjacent subcarriers are the same. In this paper, we propose efficient channel estimation and symbol decoding methods, which consider the difference between CFRs at the adjacent subcarriers of the SFBC (or the STF block coded) orthogonal frequency division multiplexing (OFDM) system in multipath fading channels. The proposed method gives initial channel information by designing a simple training symbol, and the CFRs at all the subcarriers and the differences between the CFRs are easily calculated by using an interpolation method or a discrete Fourier transform (DFT) operation.

关键词： orthogonal frequency division multiplexing space-frequency block code space-time block code space-time-frequency block code channel estimation

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A New Generalized Complex Orthogonal space-time block codes

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Journal of Shanghai University(English Edition) 2005年第3期9卷 241-243页

作者：单红梅胡光锐 Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200030 P.R. China

Recent research challenges in the wireless communication include the usage of diversity and efficient coding to improve data transmission quality and spectral efficiency. space diversity uses multiple transmitting and/or receiving antennas to create independent fading channels without penalty in bandwidth efficiency. space-time block coding is an encoding scheme for communication over Rayleigh fading channels using multiple transmitting antennas. space-time block codes from complex orthogonal designs exist only for two transmitting antennas. This paper generalizes a new complex orthogonal space-time block code for four transmitting antennas, whose decoding complexity is very low. Simulations show that the generalized complex orthogonal space-time block code has low bit error rate, full rate and possibly large diversity.

关键词： space diversity space-time block code multiple antennas generalized complex orthogonal designs.

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