space-time block coding (STBC) is a novel transmit diversity technique that can substantially improve the reliability of wireless communication channel. In this letter, we investigate single-carrier STBC block transmi...
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space-time block coding (STBC) is a novel transmit diversity technique that can substantially improve the reliability of wireless communication channel. In this letter, we investigate single-carrier STBC block transmission over frequency-selective fading channel. Based on the minimum mean square error (MMSE) criterion, by exploiting the reliability of tentative decision symbols, we propose a novel suboptimal, low complexity frequency domain decision feedback equalization (FD-DFE) scheme for SC STBC. Simulation results show that the proposed scheme provides better performance than the conventional scheme.
In this work, we present the concept of quadrature spatial modulation aided media-based modulation (QSM-MBM), which combines QSM and MBM principles. The proposed two QSM-MBM schemes use dispersion matrices to generate...
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In this work, we present the concept of quadrature spatial modulation aided media-based modulation (QSM-MBM), which combines QSM and MBM principles. The proposed two QSM-MBM schemes use dispersion matrices to generate QSM matrix and transmit it by designing two different channel state activation methods, which provides improved transmission rate, diversity gain as well as hardware simplicity. Simulations show that the proposed QSM-MBM schemes achieve remarkably better error performance than the existing MBM schemes.
A space-timeblock coded system in a correlated Rayleigh flat fading environment with transmit and receive correlation is considered. The channel state information (CSI) is estimated from a sequence of pilot code vect...
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A space-timeblock coded system in a correlated Rayleigh flat fading environment with transmit and receive correlation is considered. The channel state information (CSI) is estimated from a sequence of pilot code vectors which are known to the receiver and transmitted prior to data code transmission. Two receiver structures, namely the optimum receiver in which the estimated CSI is used in the maximum likelihood sense and the joint processing receiver that jointly processes the received data code and the received pilot code vectors, are presented an their equivalence is shown.
In this letter, we present a new result on turbo coded quasi orthogonal spacetimeblockcoding (QO-STBC) schemes. Proper utilization of soft decision information is one of the important factors affecting the performa...
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In this letter, we present a new result on turbo coded quasi orthogonal spacetimeblockcoding (QO-STBC) schemes. Proper utilization of soft decision information is one of the important factors affecting the performance of turbo codes. If a spacetimeblockcoding (STBC) scheme is used with turbo codes, the output of the STBC decoder must be fed into a turbo code decoder as soft decision information. Therefore, the performance of turbo codes depends on how the STBC scheme generates soft decision information from its detection process. In this letter, we investigate the performance of turbo coded QO-STBC schemes, and present the optimum soft decision metrics.
A constant modulus (CM)-based channel estimation scheme for space-timeblock-coded MPSK and M-QAM transmission systems is derived. Exploiting the orthogonal structure of the space-timeblock coded transmission model, ...
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A constant modulus (CM)-based channel estimation scheme for space-timeblock-coded MPSK and M-QAM transmission systems is derived. Exploiting the orthogonal structure of the space-timeblock coded transmission model, the analytical solutions to minimize the CM cost function are given for 2(k) PSK (k > 2) and 2(2k)-QAM schemes, and used to derive the expressions for the CM-based channel estimators. Illustrative results on the performance are presented.
We consider vector channel estimation for differentially modulated systems with transmit diversity. We propose a blind estimation scheme to yield superior performance to that of the pilot-aided estimation. The propose...
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We consider vector channel estimation for differentially modulated systems with transmit diversity. We propose a blind estimation scheme to yield superior performance to that of the pilot-aided estimation. The proposed scheme utilizes the repeated transmission of space-time coded data symbols. We compare the performance of the proposed blind scheme with the pilot-based estimation scheme via computer simulations.
In this paper, we investigate the performance of a single-relay cooperative scenario where the source, relay and destination terminals are equipped with multiple transmit/receive antennas. We assume that conventional ...
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In this paper, we investigate the performance of a single-relay cooperative scenario where the source, relay and destination terminals are equipped with multiple transmit/receive antennas. We assume that conventional space-timeblock codes are employed in the underlying source-to-destination (S -> D), source-to-relay (S -> R) and relay-to-destination (R -> D) links, and consider both decode-and-forward (DaF) and amplify-and-forward (AaF) relaying techniques. For the latter one, we consider two variants based on the availability of channel state information (CSI);namely, blind AaF and CSI-assisted AaF. Through the derivation of pairwise error probability, we quantify analytically the impact of multiple antenna deployment for each relaying technique under various scenarios which involve relay location and power control assumptions imposed on cooperating nodes. Our transmission model assumes that. the source and destination terminals are equipped with M-s transmit and N receive antennas, respectively, and the relay terminal is equipped with M-R receive and M-T transmit antennas. For a scenario where R -> D and S -> D links are balanced and S -> R link experiences sufficiently large SNR, our performance analysis demonstrates that the maximum achievable diversity order is M-T min(M-S, N)+MSN for blind AaF scheme and N(M-T+M-S) for both CSI-assisted AaF and DaF schemes. For another scenario where R D link has a sufficiently large SNR and S R and S D links are balanced, CSI-assisted AaF, blind AaF and DaF schemes achieve diversity orders of M-S(N + M-R), M-S(N + and M-T), and MSN respectively. Other scenarios involving the availability of non-fading R. D link and poor inter-user channel quality are further investigated. An extensive Monte Carlo simulation study is also presented to corroborate the analytical results and to provide detailed performance comparisons among the three relaying techniques under consideration.
Adaptive modulation has the potential to increase the system throughput significantly by matching transmitter parameters to time-varying channel conditions. However, adaptive modulation schemes that rely on perfect ch...
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Adaptive modulation has the potential to increase the system throughput significantly by matching transmitter parameters to time-varying channel conditions. However, adaptive modulation schemes that rely on perfect channel state information (CSI) are sensitive to CSI imperfections induced by estimation errors and feedback delays. In this paper, we design adaptive modulation schemes for multiantenna transmissions based on partial CSI, that models the spatial fading channels as Gaussian random variables with nonzero mean and white covariance, conditioned on feedback information. Based on a two-dimensional beamformer, our proposed transmitter optimally adapts the basis beams, the power allocation between two beams, and the signal constellation, to maximize the transmission rate, while maintaining a target bit-error rate. Adaptive trellis-coded multiantenna modulation is also investigated. Numerical results demonstrate the rate improvement, and illustrate an interesting tradeoff that emerges between feedback quality and hardware complexity.
Single-carrier (SC) transmission with space-timeblock coded (STBC) transmit diversity can achieve good bit error rate (BER) performance. However, in a high mobility environment, the STBC codeword orthogonality is dis...
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Single-carrier (SC) transmission with space-timeblock coded (STBC) transmit diversity can achieve good bit error rate (BER) performance. However, in a high mobility environment, the STBC codeword orthogonality is distorted and as consequence, the BER performance is degraded by the interference caused by the orthogonality distortion of STBC codeword. In this paper, we proposed a novel frequency-domain equalization (FDE) for SC-STBC transmit diversity in doubly selective fading channel. Multiple FDE weight matrices, each associated with a different code block, are jointly optimized based on the minimum mean square error (MMSE) criterion taking into account not only channel frequency variation but also channel time variation over the STBC codeword. Computer simulations confirm that the proposed robust FDE achieves BER performance superior to conventional FDE, which was designed based on the assumption of a quasi-static fading.
In this paper, unified BER performance and outage probability analyses of downlink multiuser scheduling for multiple-input multiple-output (MUS-MIMO) transmission/combining (transceiving) systems with imperfect channe...
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In this paper, unified BER performance and outage probability analyses of downlink multiuser scheduling for multiple-input multiple-output (MUS-MIMO) transmission/combining (transceiving) systems with imperfect channel state information (CSI) caused by feedback over Rayleigh fading channels is presented. The unified analysis is applicable to MIMO transceiving systems whose received signal-to-noise ratio (SNR) is given as largest order statistic of chi-square distribution. The performance of MUS-MIMO employing selective transmission/selective combining (ST/SC), ST/maximum ratio combining (MRC) and space-timeblock codes (STBC) can be analyzed by this general framework. Accurate and approximate unified closed-form BER and outage probability expressions of the MUS-MIMO transceiving system with normalized SNR-based scheduling in heterogeneous networks are derived. Based on the approximate BER and outage probability expressions, diversity gains are analyzed at high SNR. The results indicate that the MUS-MIMO for using the three transceiving schemes can achieve full diversity order for perfect CSI, while the diversity gain is degraded differently for the three transceiving schemes under imperfect CSI. Computer simulation shows that the theoretical analysis is in good agreement with simulation results, and the approximate BER expressions are very close to the accurate ones but with lower computational complexity.
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