• Title/Summary/Keyword: Cooperative multiple-input multiple-output (MIMO)

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Energy Saving in Cluster-Based Wireless Sensor Networks through Cooperative MIMO with Idle-Node Participation

  • Fei, Li;Gao, Qiang;Zhang, Jun;Wang, Gang
    • Journal of Communications and Networks
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    • v.12 no.3
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    • pp.231-239
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    • 2010
  • In cluster-based wireless sensor networks, the energy could be saved when the nodes that have data to transmit participate in cooperative multiple-input multiple-output (MIMO). In this paper, by making the idle nodes that have no data to transmit participate in the cooperative MIMO, it is found that much more energy could be saved. The number of the idle nodes that participate in the cooperative MIMO is optimized to minimize the total energy consumption. It is also found that the optimal number of all the nodes participating in cooperative communication does not vary with the number of nodes that have data to transmit. The proposition is proved mathematically. The influence of long-haul distance and modulation constellation size on the total energy consumption is investigated. A cooperative MIMO scheme with help-node participation is proposed and the simulation results show that the proposed scheme achieves significant energy saving.

Energy-efficient data transmission technique for wireless sensor networks based on DSC and virtual MIMO

  • Singh, Manish Kumar;Amin, Syed Intekhab
    • ETRI Journal
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    • v.42 no.3
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    • pp.341-350
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    • 2020
  • In a wireless sensor network (WSN), the data transmission technique based on the cooperative multiple-input multiple-output (CMIMO) scheme reduces the energy consumption of sensor nodes quite effectively by utilizing the space-time block coding scheme. However, in networks with high node density, the scheme is ineffective due to the high degree of correlated data. Therefore, to enhance the energy efficiency in high node density WSNs, we implemented the distributed source coding (DSC) with the virtual multiple-input multiple-output (MIMO) data transmission technique in the WSNs. The DSC-MIMO first compresses redundant source data using the DSC and then sends it to a virtual MIMO link. The results reveal that, in the DSC-MIMO scheme, energy consumption is lower than that in the CMIMO technique; it is also lower in the DSC single-input single-output (SISO) scheme, compared to that in the SISO technique at various code rates, compression rates, and training overhead factors. The results also indicate that the energy consumption per bit is directly proportional to the velocity and training overhead factor in all the energy saving schemes.

Energy-Efficiency and Transmission Strategy Selection in Cooperative Wireless Sensor Networks

  • Zhang, Yanbing;Dai, Huaiyu
    • Journal of Communications and Networks
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    • v.9 no.4
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    • pp.473-481
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    • 2007
  • Energy efficiency is one of the most critical concerns for wireless sensor networks. By allowing sensor nodes in close proximity to cooperate in transmission to form a virtual multiple-input multiple-output(MIMO) system, recent progress in wireless MIMO communications can be exploited to boost the system throughput, or equivalently reduce the energy consumption for the same throughput and BER target. However, these cooperative transmission strategies may incur additional energy cost and system overhead. In this paper, assuming that data collectors are equipped with antenna arrays and superior processing capability, energy efficiency of relevant traditional and cooperative transmission strategies: Single-input-multiple-output(SIMO), space-time block coding(STBC), and spatial multiplexing(SM) are studied. Analysis in the wideband regime reveals that, while receive diversity introduces significant improvement in both energy efficiency and spectral efficiency, further improvement due to the transmit diversity of STBC is limited, as opposed to the superiority of the SM scheme especially for non-trivial spectral efficiency. These observations are further confirmed in our analysis of more realistic systems with limited bandwidth, finite constellation sizes, and a target error rate. Based on this analysis, general guidelines are presented for optimal transmission strategy selection in system level and link level, aiming at minimum energy consumption while meeting different requirements. The proposed selection rules, especially those based on system-level metrics, are easy to implement for sensor applications. The framework provided here may also be readily extended to other scenarios or applications.

Energy Efficient Cooperative LEACH Protocol for Wireless Sensor Networks

  • Asaduzzaman, Asaduzzaman;Kong, Hyung-Yun
    • Journal of Communications and Networks
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    • v.12 no.4
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    • pp.358-365
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    • 2010
  • We develop a low complexity cooperative diversity protocol for low energy adaptive clustering hierarchy (LEACH) based wireless sensor networks. A cross layer approach is used to obtain spatial diversity in the physical layer. In this paper, a simple modification in clustering algorithm of the LEACH protocol is proposed to exploit virtual multiple-input multiple-output (MIMO) based user cooperation. In lieu of selecting a single cluster-head at network layer, we proposed M cluster-heads in each cluster to obtain a diversity order of M in long distance communication. Due to the broadcast nature of wireless transmission, cluster-heads are able to receive data from sensor nodes at the same time. This fact ensures the synchronization required to implement a virtual MIMO based space time block code (STBC) in cluster-head to sink node transmission. An analytical method to evaluate the energy consumption based on BER curve is presented. Analysis and simulation results show that proposed cooperative LEACH protocol can save a huge amount of energy over LEACH protocol with same data rate, bit error rate, delay and bandwidth requirements. Moreover, this proposal can achieve higher order diversity with improved spectral efficiency compared to other virtual MIMO based protocols.

Cooperative Synchronization and Channel Estimation in Wireless Sensor Networks

  • Oh Mi-Kyung;Ma Xiaoli;Giannakis Georgios B;Park Dong-Jo
    • Journal of Communications and Networks
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    • v.7 no.3
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    • pp.284-293
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    • 2005
  • A critical issue in applications involving networks of wireless sensors is their ability to synchronize, and mitigate the fading propagation channel effects. Especially when distributed 'slave' sensors (nodes) reach-back to communicate with the 'master' sensor (gateway), low power cooperative schemes are well motivated. Viewing each node as an antenna element in a multi-input multi-output (MIMO) multi-antenna system, we design pilot patterns to estimate the multiple carrier frequency offsets (CFO), and the multiple channels corresponding to each node-gateway link. Our novel pilot scheme consists of non-zero pilot symbols along with zeros, which separate nodes in a time division multiple access (TDMA) fashion, and lead to low complexity schemes because CFO and channel estimators per node are decoupled. The resulting training algorithm is not only suitable for wireless sensor networks, but also for synchronization and channel estimation of single- and multi-carrier MIMO systems. We investigate the performance of our estimators analytically, and with simulations.

Performance of MIMO-OFDM Systems using The Relay With Multi-Antennas for Cooperative Diversity (Put English Title Here) (다중 안테나의 relay를 가진 MIMO-OFDM시스템의 Cooperative diversity에 따른 성능)

  • Kim, Chan-Kyu;Kim, Young-Il
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.6
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    • pp.13-19
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    • 2008
  • In this paper, the new cooperative communication techniques is proposed for multi-input multi-output(MIMO)-orthogonal frequency division multiplexing (OFDM) system using the relay with multiple antenna. As the MIMO channel is formed by space time coding at the MS(mobile station)-RS(relay station) and RS-BS(base station), we can get the cooperative diversity and MIMO diversity gain simultaneously. Therefore, the performance of MIMO-OFDM system using the relay with multiple-antennas is very improved. And the simple power allocation technique is Proposed for the transmitting power of the mobile station and the relay.

The performance of MIMO cooperative communication systems using the relay with multi-antennas and DSTC

  • Chan Kyu Kim
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.3
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    • pp.14-23
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    • 2023
  • The cooperative communication systems using MIMO(multiple input multiple-output) relay are known as one of the most promising techniques to improve the performance and coverage of wireless communication systems. In this paper, we propose the cooperative communication systems using the relay with multi-antennas and DSTC(distributed space time coding) for decode-and-forward protocol. As using DSTC for DF(decode-and-forward), we can minimize the risk of error propagation at the wireless system using relay system. Also, the MIMO channel cab be formed by multi-antenna and DSTC at the MS(mobile station)-RS(relay station) and at the RS-BS(base station).Therefore, obtaining truly constructive the MIMO diversity and cooperative diversity gain from the proposed approach, the performance of system can be more improved than one of conventional system (relay with single antenna, no relay). The improvement in bit error rate is investigated through numerical analysis of the cooperative communication system with the proposed approach.

Cooperative MIMO Channel Simulation Based on the Geometrical Ring Model (기하학적 Ring 모델에 기반을 둔 협력형 MIMO 채널 시뮬레이터)

  • Yang, Mi-Sun;Kim, Dong-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.3A
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    • pp.235-239
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    • 2008
  • In this paper, we study a simulation model for cooperative MIMO (multiple-input multiple-output) channels and present a cooperative one-ring channel model which is extended from the geometrical one-ring and two-ring scattering models. Assuming that the source, the destination and the relay are surrounded by an infinite number of scatters, we derive a reference model for the cooperative one-ring channel and propose a simulation model based on the reference model provided in the paper. Then we show how modeling parameters of the simulation model are determined to match the correlation functions for the respective models. With numerical investigation, we also show that the correlation functions for the reference and the simulation are well matched.

Performance of Distributed MISO Systems Using Cooperative Transmission with Antenna Selection

  • Park, Jong-Hyun;Kim, Jae-Won;Sung, Won-Jin
    • Journal of Communications and Networks
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    • v.10 no.2
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    • pp.163-174
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    • 2008
  • Performance of downlink transmission strategies exploiting cooperative transmit diversity is investigated for distributed multiple-input single-output (MISO) systems, for which geographically distributed remote antennas (RA) in a cell can either communicate with distinct mobile stations (MS) or cooperate for a common MS. Statistical characteristics in terms of the signal-to-interference-plus-noise ratio (SINR) and the achievable capacity are analyzed for both cooperative and non-cooperative transmission schemes, and the preferred mode of operation for given channel conditions is presented using the analysis result. In particular, we determine an exact amount of the maximum achievable gain in capacity when RAs for signal transmission are selected based on the instantaneous channel condition, by deriving a general expression for the SINR of such antenna selection based transmission. For important special cases of selecting a single RA for non-cooperative transmission and selecting two RAs for cooperative transmission among three RAs surrounding the MS, closed-form formulas are presented for the SINR and capacity distributions.

Rate Bounds for MIMO Relay Channels

  • Lo, Caleb K.;Vishwanath, Sriram;Heath, Jr., Robert W.
    • Journal of Communications and Networks
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    • v.10 no.2
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    • pp.194-203
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    • 2008
  • This paper considers the multi-input multi-output (MIMO) relay channel where multiple antennas are employed by each terminal. Compared to single-input single-output (SISO) relay channels, MIMO relay channels introduce additional degrees of freedom, making the design and analysis of optimal cooperative strategies more complex. In this paper, a partial cooperation strategy that combines transmit-side message splitting and block-Markov encoding is presented. Lower bounds on capacity that improve on a previously proposed non-cooperative lower bound are derived for Gaussian MIMO relay channels.