multiple-input multiple-output(MIMO) technology can be used in cyclic prefix single carrier(CPSC) systems to improve communication quality and *** paper proposes a blind channel estimation method for MIMO-CPSC systems...
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multiple-input multiple-output(MIMO) technology can be used in cyclic prefix single carrier(CPSC) systems to improve communication quality and *** paper proposes a blind channel estimation method for MIMO-CPSC systems with repetition *** algorithm makes use of the redundancy introduced by the repetition scheme at the transmitter to identify the channel based on a subspace ***,the proposed method obtains accurate channel estimation with fewer received *** numerical results are provided to illustrate the effectiveness of the proposed blind channel estimation method.
It discusses the channel estimation algorithm of *** of the complexity of the matrix inversion computation in LS algorithm,we use QR decomposition in LS,that is ***,the complexity of LS algorithm can be *** the simula...
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It discusses the channel estimation algorithm of *** of the complexity of the matrix inversion computation in LS algorithm,we use QR decomposition in LS,that is ***,the complexity of LS algorithm can be *** the simulation of the LS and QRD-LS *** can see that the performance of these two algorithm is ***,the QRD-LS algorithm has no matrix ***,this algorithm can simplify the calculation.
The effect of co-channel interference (CCI) is considered in multiple-input multiple-output (MIMO) systems employing maximal ratio combining (MRC) under independent and identically distributed Rayleigh fading. Closed-...
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The effect of co-channel interference (CCI) is considered in multiple-input multiple-output (MIMO) systems employing maximal ratio combining (MRC) under independent and identically distributed Rayleigh fading. Closed-form capacity and symbol error rate expressions are presented to evaluate the performance without any numerical integrations or statistical simulations. The analytical results are compared with Monte Carlo simulations and the good agreement is obtained.
In this paper we implement a first multi-gigabit real-time dual-polarization CO-OFDM receiver in a 2 x 2 multiple-input multiple-output (MIMO) configuration. The experimental setup consists of four 1.5 Giga samples pe...
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In this paper we implement a first multi-gigabit real-time dual-polarization CO-OFDM receiver in a 2 x 2 multiple-input multiple-output (MIMO) configuration. The experimental setup consists of four 1.5 Giga samples per second (GS/s) high-speed analog-to-digital converters (ADC) and one Stratix III field-programmable gate array (FPGA). The signal streams are processed in real-time mode, and the data rates of 3.33 Gb/s and 6.67 Gb/s are realized for 4-QAM and 16-QAM, respectively.
A novel semi-blind space-time equaliser (STE) is proposed for dispersive multiple-input multiple-output systems that employ high-throughput quadrature amplitude modulation signalling. A minimum number of training symb...
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A novel semi-blind space-time equaliser (STE) is proposed for dispersive multiple-input multiple-output systems that employ high-throughput quadrature amplitude modulation signalling. A minimum number of training symbols, approximately equal to the dimension of the STE, are first utilised to provide a rough initial least squares estimate of the STE's weight vector. A concurrent gradient-Newton constant modulus algorithm and soft decision-directed scheme is then applied to adapt the STE. The proposed semi-blind adaptive STE is capable of converging fast to the minimum mean square error STE solution. Simulation results confirms that the convergence speed of this semi-blind adaptive algorithm is very close to that of the training-based recursive least squares algorithm.
For multiple-input multiple-output （MIMO） orthogonal frequency division multiplexing （OFDM） systems, a joint timing synchronization and frequency offset acquisition algorithm based on fractional Fourier transform ...
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For multiple-input multiple-output （MIMO） orthogonal frequency division multiplexing （OFDM） systems, a joint timing synchronization and frequency offset acquisition algorithm based on fractional Fourier transform （FRFT） is proposed. The linear frequency modulation signals superimposed on the data signals are used as the training signals. By performing FRFT on the received signals and searching the peak value of the FRFT results, the receiver can realize timing synchronization and frequency offset acquisition simultaneously. Compared with the existing methods, the proposed algorithm can provide better timing synchronization performance and larger frequency offset acquisition range even under multi-path channels with low signal to noise ratio. Theoretical analysis and simulation results prove this point.
In this paper, we study the optimal training and data transmission strategies for block fading multiple-input multiple-output (MIMO) systems with feedback. We consider both the channel gain feedback (CGF) system and t...
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In this paper, we study the optimal training and data transmission strategies for block fading multiple-input multiple-output (MIMO) systems with feedback. We consider both the channel gain feedback (CGF) system and the channel covariance feedback (CCF) system. Using an accurate capacity lower bound as a figure of merit that takes channel estimation errors into account, we investigate the optimization problems on the temporal power allocation to training and data transmission as well as the training length. For CGF systems without feedback delay, we prove that the optimal solutions coincide with those for nonfeedback systems. Moreover, we show that these solutions stay nearly optimal even in the presence of feedback delay. This finding is important for practical MIMO training design. For CCF systems, the optimal training length can be less than the number of transmit antennas, which is verified through numerical analysis. Taking this fact into account, we propose a simple yet near optimal transmission strategy for CCF systems, and derive the optimal temporal power allocation over pilot and data transmission.
This letter proposes a hybrid transmission scheme by combining zero-forcing beamforming (ZFBF) and orthogonal beamforming (OBF) for the multiple-input multiple-output broadcast channel. This method first utilizes ZFBF...
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This letter proposes a hybrid transmission scheme by combining zero-forcing beamforming (ZFBF) and orthogonal beamforming (OBF) for the multiple-input multiple-output broadcast channel. This method first utilizes ZFBF for only a part of the scheduled users with approximately orthogonal channels. By further constructing orthogonal beamformers in the null space of the ZFBF user channels, it then employs OBF for the rest of users to fully exploit the spatial dimension. Theoretical analysis, as well as simulation results, verify that our scheme outperforms the conventional ZFBF scheme and OBF scheme with user selection.
In this paper, a fist sphere decoder is proposed for the joint detection of phase-shift keying (PSK) signals in uncoded Vertical Bell Laboratories Layered Space Time (V-BLAST) systems. The proposed decoder consists of...
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In this paper, a fist sphere decoder is proposed for the joint detection of phase-shift keying (PSK) signals in uncoded Vertical Bell Laboratories Layered Space Time (V-BLAST) systems. The proposed decoder consists of preprocessing stage and search stage. The preprocessing stage is based oil the enhancement of the ordering mean square error decision feedback equalizer (MMSE-DFE). Its role is to generate a tree structure Suitable for the search stage. The search stage relies on the depth-first brand-and-bound (BB) algorithm with "best-first" orders stored in lookup tables. Simulation results show that the proposed decoder is able to provide the system with the maximum likelihood (ML) performance at low complexity. (C) 2008 Elsevier B.V. All rights reserved.
We study the optimal antenna configuration (i.e. number of transmit anti receive antennas) for multiple-input multiple-output systems in pilot-symbol-assisted modulation schemes with imperfect channel estimation. We a...
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We study the optimal antenna configuration (i.e. number of transmit anti receive antennas) for multiple-input multiple-output systems in pilot-symbol-assisted modulation schemes with imperfect channel estimation. We assume block flat-fading channels and focus on a practical range of high signal-to-noise ratio. An ergodic capacity lower bound is used as the objective function to be maximized. We analytically study the capacity gain from adding extra antennas to the transmitter or to the receiver in two different scenarios. Our numerical results show that the optimal antenna configuration under imperfect channel estimation can be significantly different from that under perfect channel estimation assumption. In addition, we investigate the capacity gain from optimizing antenna configuration and find that the gain can be larger than that achieved by optimizing transmit power over pilot and data symbols, particularly for large block lengths.
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