Zhimeng Zhong

Shanghai Jiao Tong University, Shanghai, Shanghai Shi, China

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Publications (23)8.36 Total impact

  • Source
    Zhimeng Zhong · Shihua Zhu · A. Nallanathan
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    ABSTRACT: In cooperative communication networks, the performance of distributed space-time code will be severely degraded if the timing synchronization among relay nodes is not perfect. In this letter, we propose a systematic construction of the so called distributed linear convolutional space-time code (DLCSTC) for multipath fading channels that does not require the synchronization assumption. We derive sufficient conditions on the code design such that the full cooperative and multipath diversities can be achieved under the minimum memory length constraint. Then we design DLCSTCs that both have the traceorthonormality property and achieve the full diversity. We show that the proposed codes can also achieve the full diversity for asynchronous cooperative communications with ZF, MMSE and MMSE-DFE receivers under frequency-selective channels. Finally, various numerical examples are provided to corroborate the analytical studies.
    IEEE Transactions on Wireless Communications 09/2009; 8(8-8):3944 - 3949. DOI:10.1109/TWC.2009.081181 · 2.76 Impact Factor
  • Zhimeng Zhong · Shihua Zhu · A. Nallanathan
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    ABSTRACT: In cooperative communication networks, the performance of the distributed space-time code (DSTC) will be severely degraded if the timing synchronization among relay nodes are not perfect. In this paper, we propose a systematic construction of the so called distributed linear convolutional space-time code (DLCSTC) for multipath fading channels that does not require the synchronization assumption. We derive sufficient conditions on the code design such that the full cooperative and multipath diversities can be achieved under the minimum memory length constraint. Then we design DLCSTCs that both have the trace-orthonormality property and achieve the full diversity. We also study the diversity property of the DLCSTC with suboptimal receivers. We show that the proposed codes can also achieve the full diversity for asynchronous cooperative communications with ZF, MMSE and MMSE-DFE receivers under frequency-selective channels. Finally, various numerical examples are provided to corroborate the analytical studies.
    Communications, 2009. ICC '09. IEEE International Conference on; 07/2009
  • Zhimeng Zhong · Shihua Zhu · Gangming Lv
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    ABSTRACT: In this paper, we consider asynchronous two-way wireless relay networks with amplify-and-forward protocol (AF- TWRN), where the distributed space-time code (DSTC) is utilized without synchronization among relays to assist the communication between two terminals. We analyze the pairwise error probability (PEP) behavior of DSTC for AF-TWRN under frequency-selective channels. From our analysis, it is seen that of the paths from one terminal to relays and from relays to another terminal, those with smaller diversity order result in an overall system performance bottleneck. Considering both the timing errors among relays and the multipath fading, we then propose a family of distributed convolutional space-time codes (DCSTC) for AF-TWRN such that the full diversity order can be achieved. Finally, various numerical examples are provided to corroborate the analytical studies.
    Communications, 2009. ICC '09. IEEE International Conference on; 07/2009
  • Zhenzhen Gao · Shihua Zhu · Jing Xu · Zhimeng Zhong
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    ABSTRACT: In this letter, a relay-assisted transmission scenario over frequency-selective fading channels perturbed by different random carrier frequency offsets is considered. OFDM and block-double differential (BDD) design are implemented to overcome the problem of intersymbol interference (ISI) and carrier frequency offsets (CFOs). We analyze the symbol error rate (SER) performance of decode-and-forward relaying with BDD design in wireless cooperative communications over frequency-selective fading channels and derive a theoretical upper bound for average SER when the relay (R) is error free. It can be seen from our analysis that the system performance is influenced by the ability of R to decode, and when R decodes without error, both spatial and multipath diversity can be obtained without requiring any knowledge of channel state information and CFO information at the receivers. Numerical examples are provided to corroborate our theoretical analysis.
    IEICE Transactions on Communications 07/2009; 92-B(7):2507-2511. DOI:10.1587/transcom.E92.B.2507 · 0.33 Impact Factor
  • Gangming Lv · Shihua Zhu · Zhimeng Zhong
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    ABSTRACT: A delay-oriented packet scheduling scheme is proposed for downlink OFDMA networks with heterogeneous delay requirements. Using a novel packet utility concept, the proposed algorithm can exploit diversity from traffic characteristics and requirements to improve delay performance for delay sensitive traffics. Besides, the proposal also shows good ability in balancing fairness and efficiency. Simulation results show that our proposal outperforms existing delay-oriented scheduling schemes in terms of both delay performance and spectrum efficiency.
    IEICE Transactions on Communications 06/2009; 92-B(6):2336-2340. DOI:10.1587/transcom.E92.B.2336 · 0.33 Impact Factor
  • Source
    Zhimeng Zhong · Shihua Zhu · Arumugam Nallanathan
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    ABSTRACT: In most cooperative communication works, perfect synchronization among relay nodes is assumed in order to achieve the cooperative diversity. However, this assumption is not realistic due to the distributed nature of each relay node. In this paper, we propose a family of distributed space-time trellis code (DSTTC) that does not require the synchronization assumption. It is shown that the proposed DSTTC has minimum memory order, and the construction of such DSTTCs is equivalent to using the generator matrices that have full row rank, regardless of sub-matrices shifting problem. Here, a sub-matrix corresponds to the generator matrix of a relay node under frequency-selective channels. We derive sufficient conditions on the code design such that the full cooperative and multipath diversities can be achieved. By further studying the diversity product, we design the DSTTCs which can achieve full diversity and the maximum coding gain through the exhaustive computer search. The newly proposed codes exhibit good properties, e.g., high energy efficiency and low synchronization cost, and can be applied to distributed wireless networks. Finally, various numerical examples are provided to corroborate the analytical studies.
    IEEE Transactions on Wireless Communications 03/2009; 8(2-8):796 - 805. DOI:10.1109/TWC.2009.071018 · 2.76 Impact Factor
  • Source
    Zhimeng Zhong · Shihua Zhu · Arumugam Nallanathan
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    ABSTRACT: In most cooperative communications works, perfect synchronization among relay nodes is assumed in order to achieve cooperative diversity. However, this assumption is not realistic due to the distributed nature of each relay node. In this paper, we propose a family of distributed space-time trellis code (DSTTC) that does not require the synchronization assumption. It is shown that the proposed DSTTC can achieve full cooperative and full multipath diversities for the asynchronous transmission by utilizing a specifically designed generator matrix. We derive sufficient conditions on the DSTTC with the minimum memory order. Finally, various numerical examples are provided to verify the analytical studies. The newly proposed codes exhibit good properties, e.g. high energy efficiency and low synchronization cost, and can be applied to distributed wireless networks.
    Global Telecommunications Conference, 2008. IEEE GLOBECOM 2008. IEEE; 01/2009
  • Erlin Zeng · Shihua Zhu · Xuewen Liao · Zhimeng Zhong
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    ABSTRACT: This letter analyzes the outage probability of limited feedback beamforming systems with receive antenna selection. Tight analytical closed-form expressions of outage performance are derived for both cases, with and without spatial fading correlation, which allow for evaluation of the performance as a function of the codebook size, the level of fading correlation, and the number of transmit and receive antennas. Simulation results are also provided to verify the analysis.
    IEICE Transactions on Communications 12/2008; 91-B(12):4034-4037. DOI:10.1093/ietcom/e91-b.12.4034 · 0.33 Impact Factor
  • Zhimeng Zhong · Shihua Zhu · Gangming Lv
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    ABSTRACT: In this letter, we analyze the pairwise error probability (PEP) behaviour of distributed space-time code (DSTC) with amplify-and-forward relaying over Nakagami- m multipath channels. An upper bound of PEP for DSTC is derived. From our analysis, it is seen that of the paths from the source to relays and from relays to the destination, those with smaller diversity order result in an overall system performance bottleneck. Numerical examples are provided to corroborate our theoretical analysis.
    IEICE Transactions on Communications 11/2008; E91B(11). DOI:10.1093/ietcom/e91-b.11.3740 · 0.33 Impact Factor
  • Zhimeng Zhong · Shihua Zhu · Gangming Lv · Tao Liu
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    ABSTRACT: In most cooperative communications works, perfect synchronization among relay nodes is assumed in order to achieve cooperative diversity. However, this assumption is not realistic due to the distributed nature of each relay node. In this paper, we propose a new distributed space-time coded transmission (DSTCT) scheme for asynchronous cooperative communications under frequency-selective channels. First, a novel transmission protocol, in which each relay is labelled in delay-ascending order, is proposed. Second, the pairwise error probability and the design criterion of DSTCT are derived. Finally, based on the proposed transmission protocol and the design criterion, a new DSTCT scheme for asynchronous cooperative communications is proposed. Theoretical analysis and simulation results show that this scheme can achieve both full cooperative diversity and full multipath diversity.
    Vehicular Technology Conference, 2008. VTC 2008-Fall. IEEE 68th; 10/2008
  • Erlin Zeng · Shihua Zhu · Xuewen Liao · Zhimeng Zhong · Zhenjie Feng
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    ABSTRACT: Prior studies on limited feedback (LFB) beamforming in multiple-antenna orthogonal frequency division multiplexing (OFDM) have resorted to Monte-Carlo simulations to evaluate the system performance. This letter proposes a novel analytical framework, based on which the averaged signal-to-noise ratio and the ergodic capacity performance of clustering-based LFB beamforming in multiple-antenna OFDM systems are studied. Simulations are also provided to verify the analysis.
    IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences 07/2008; 91-A:1850-1853. DOI:10.1093/ietfec/e91-a.7.1850 · 0.23 Impact Factor
  • Zhenzhen Gao · Shihua Zhu · Zhimeng Zhong
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    ABSTRACT: A new high-rate space-time block code (STBC) with full transmit diversity gain for four transmit antennas based on a generalized Alamouti code structure is proposed. The proposed code has lower Maximum Likelihood (ML) decoding complexity than the Double ABBA scheme does. Constellation rotation is used to maximize the diversity product. With the optimal rotated constellations, the proposed code significantly outperforms some known high-rate STBCs in the literature with similar complexity and the same spectral efficiency.
    IEICE Transactions on Communications 07/2008; 91-B(7):2431-2434. DOI:10.1093/ietcom/e91-b.7.2431 · 0.33 Impact Factor
  • Erlin Zeng · Shihua Zhu · Xuewen Liao · Zhimeng Zhong · Zhenjie Feng
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    ABSTRACT: Prior studies have shown that the performance of amplify-and-forward (AF) relay systems can be considerably improved by using multiple antennas and low complexity linear processing at the relay nodes. However, there is still a lack of performance analysis for the cases where the processing is based on limited feedback (LFB). Motivated by this, we derive the closed-form expression of the outage probability of AF relay systems with LFB beamforming in this letter. Simulation results are also provided to confirm the analytical studies.
    IEICE Transactions on Communications 06/2008; 91-B(6):2053-2057. DOI:10.1093/ietcom/e91-b.6.2053 · 0.33 Impact Factor
  • Erlin Zeng · Shihua Zhu · Zhimeng Zhong · Zhenjie Feng
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    ABSTRACT: In this letter, we analyze the performance of limited feedback beamforming in a distributed antenna system. We propose a novel codebook design scheme to maximize a lower bound of the averaged effective signal-to-noise ratio (SNR), which is a function of the power of the signal and noise, the number of antennas, and the number of total feedback bits for characterizing the quantized channel vector. Simulations verify that the proposed scheme can provide effective capacity improvement.
    IEICE Transactions on Communications 06/2008; 91-B(6):2063-2066. DOI:10.1093/ietcom/e91-b.6.2063 · 0.33 Impact Factor
  • Erlin Zeng · Zhimeng Zhong · Shihua Zhu
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    ABSTRACT: In this letter, we study the performance of the multiple-input multiple-output macrodiversity transmission with limited feedback. We modify the model of the quantized channel by Jindal [9] such that the phase ambiguity in the vector quantization procedure can be characterized. Using the modified model, we show that the conventional limited feedback methods cannot obtain the macrodiversity gain even with asymptotically large codebook size, and that the macrodiversity gain can be attained by adding only one bit of phase feedback.
    IEICE Transactions on Communications 06/2008; E91B(6):2033-2036. DOI:10.1093/ietcom/e91-b.6.2033 · 0.33 Impact Factor
  • Zhimeng Zhong · Shihua Zhu · Gangming Lv
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    ABSTRACT: An orthogonal multi-relay network is investigated, where the transmissions are separated into two phases which are orthogonalized in time-frequency plane in order to satisfy practical constraints. In phase I, the source transmits to the relays and destination. In phase II, the relays transmit to the destination simultaneously. The capacity bounds on such orthogonal multi-relay networks are derived. We find that the optimal resource allocation problems for maximizing these capacity bounds are equivalent to the multi-objective optimization problems. We then propose a resource allocation scheme that converts such multi-objective optimization problems to the convex optimization problems. Simulation results show that our resource allocation has a significant impact on the performance.
    Communication Systems Software and Middleware and Workshops, 2008. COMSWARE 2008. 3rd International Conference on; 02/2008
  • Source
    Erlin Zeng · Shihua Zhu · Xuewen Liao · Zhimeng Zhong
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    ABSTRACT: In this paper, we study the performance of the multiple-input multiple-output macrodiversity transmission with limited feedback. The downlink scenario, where multiple transmitters serve the user simultaneously, is considered. We find it necessary to modify the model of the quantized channel by Jinal (2006) such that the phase ambiguity in the vector quantization procedure can be characterized. Using the modified model, we show that the conventional limited feedback methods cannot obtain the macrodiversity gain even when the size of the codebook is asymptotically large, and that the macrodiversity gain can be attained by adding only one bit of phase feedback. Our analysis can apply to both random vector quantization and any fixed codebook setup, and is verified by the simulation results.
    Wireless Communications and Networking Conference, 2008. WCNC 2008. IEEE; 01/2008
  • Source
    Zhimeng Zhong · Shihua Zhu · Gangming Lv · Jing Xu
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    ABSTRACT: In this paper, we study the asynchronous cooperative diversity schemes employing the amplify-and-forward (AF) protocols over the frequency-selective channel. We consider three time-division-multiple-access (TDMA) based cooperation protocols and derive the corresponding pairwise error probabilities (PEP). From our analysis, it is seen that of the paths from the source to relays and from relays to the destination, those with smaller diversity order result in the bottleneck for the overall system performance. We propose a new type of the distributed space-time trellis code (DSTTC) that can achieve full diversity for the asynchronous transmission by utilizing a specifically designed generator matrix. The optimal DSTTCs with the minimum memory order are found by the exhaustive computer search. Finally, various numerical examples are provided to corroborate the analytical studies.
    Proceedings of the Global Communications Conference, 2008. GLOBECOM 2008, New Orleans, LA, USA, 30 November - 4 December 2008; 01/2008
  • Source
    Jing Xu · Shihua Zhu · Zhimeng Zhong
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    ABSTRACT: Exploiting the desirable properties of cyclic group coding, we develop a full-rate differential distributed space- frequency coding (DSFC) in the frequency domain for broadband non-regenerative wireless relaying systems. The pairwise error probability analysis demonstrates that our scheme guarantees a diversity order of Gd les min{ML1, ML2}, where M is the number of the relay nodes, and L1 and L2 are the number of taps of source-to-relay and relay-to-destination channels, respectively. A novel subcarrier allocation method without channel state information (CSI) at any node is proposed to improve the diversity product. Moreover, for an arbitrary number of relays, a competitive non-regenerative DSFC proposed by Zhang et. aL, is extended to differential transmission incorporated with the proposed subcarrier allocation method for fair comparison. Both theoretical analysis and simulation results confirm that the proposed DSFC outperforms Zhang's scheme significantly in the differential case.
    Proceedings of the Global Communications Conference, 2008. GLOBECOM 2008, New Orleans, LA, USA, 30 November - 4 December 2008; 01/2008
  • Zhimeng Zhong · Shihua Zhu · Gangming Lv
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    ABSTRACT: In this paper, we design a new type of distributed space-time code (DSTC) for space-time cooperation scheme without the timing synchronization assumption. The construction of proposed DSTC is based on the construction of a special generator matrix. Both theoretical analysis and numerical results show that our DSTC can achieve full diversity for the asynchronous space-time cooperation.