Single-carrier (SC) space-timeblock coded (STBC) time-division duplex (TDD) transmission achieves a good bit-error rate (BER) performance while the channel state information (CSI) is not required at the mobile termin...
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ISBN:
(纸本)9781479909599
Single-carrier (SC) space-timeblock coded (STBC) time-division duplex (TDD) transmission achieves a good bit-error rate (BER) performance while the channel state information (CSI) is not required at the mobile terminal (MT). However, in a high mobility environment, the channel changes within a STBC codeword and the BER performance significantly degrades due to the interference caused by the orthogonality distortion of STBC codeword. In this paper, we propose a multi-block (MB)-frequency-domain equalization (FDE) for SC-STBC-TDD transmission in a high mobility environment. The STBC codeword consists of multiple signal blocks. The proposed MB-FDE uses jointly optimized multiple FDE weight matrices, each associated with each signal block in a STBC codeword. We evaluate, by computer simulation, the BER performance when using the proposed transmit/receive MB-FDE and show that the proposed MB-FDE achieves a good BER performance in a high mobility environment.
Orthogonal Frequency Division Multiplexing (OFDM) is recognized as high data rate transmission technique. Further, application of space-time block coding (STBC) to the OFDM system may help in combating severe affects ...
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ISBN:
(纸本)9781479925711
Orthogonal Frequency Division Multiplexing (OFDM) is recognized as high data rate transmission technique. Further, application of space-time block coding (STBC) to the OFDM system may help in combating severe affects of fading. In this paper, spacetimeblock encoded time frequency training OFDM (TFT-OFDM) system is proposed. The TFT-OFDM signal is trained in both time and frequency domain by appending the training sequence and by inserting the grouped pilots, respectively. Such structure of signal helps in providing better spectral efficiency and reliability. The performance of proposed system is analyzed over fast fading channel and compared with various STBC based OFDM transmission schemes. These various STBC-based OFDM transmission techniques are STBC-based cyclic prefix OFDM (CP-OFDM), STBC-based zero padding OFDM (ZP-OFDM), and STBC-based time domain synchronous OFDM (TDS-OFDM). Simulation results indicate that the STBC-based TFT-OFDM is better than other STBC-based OFDM transmission techniques in BER performance.
Orthogonal Frequency Division Multiplexing (OFDM) is a popular modulation technique that provides high data rates and good robustness against frequency selective fading. space-time block coding (STBC) is an efficient ...
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ISBN:
(纸本)9781479971626
Orthogonal Frequency Division Multiplexing (OFDM) is a popular modulation technique that provides high data rates and good robustness against frequency selective fading. space-time block coding (STBC) is an efficient way to introduce space-time diversity in Multiple-Input Multiple-Output (MIMO) systems. Using non-linear modulations such as Continuous Phase Modulation (CPM) with its constant envelope and continuous phase properties could be a solution to construct MIMO OFDM systems and to avoid the structural limitations of linear codes and alleviate the typical PAPR issue of OFDM. However, a major issue with CPM based systems may remain: the decoding complexity. In this paper, we introduce a new space-time-frequency diversity technique based on L2-orthogonal multi-h CPM space-time codes designed for OFDM transmission. We benchmark these codes under Rayleigh frequency selective channels and show how they achieve full spatial diversity at full rate for any number of antennas, good spectral compactness and also robustness to frequency fading. Furthermore, the decoding complexity is highly reduced and even made linear in the number of antennas thanks to the orthogonality properties.
Recently, we proposed a multi-block frequencydomain equalization (MB-FDE) for single-carrier space-timeblock coded time-division duplex (SC-STBC TDD) transmission. In this paper, we propose an adaptive two-dimension ...
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ISBN:
(纸本)9789860334074
Recently, we proposed a multi-block frequencydomain equalization (MB-FDE) for single-carrier space-timeblock coded time-division duplex (SC-STBC TDD) transmission. In this paper, we propose an adaptive two-dimension (2D) multi-input multi-output (MIMO) channel estimation (CE) for SCSTBC TDD transmission in a high mobility environment. In the proposed adaptive 2D-MIMO-CE, the channel over consecutive data blocks is directly estimated by using jointly optimized multiple 2D filters, each associated with each pilot block, based on minimum mean square error (MMSE) criterion. We evaluate, by computer simulation, the BER performance when using SCSTBC TDD transmission with MB-FDE and the adaptive 2D MIMO-CE and showed that the adaptive 2D MIMO-CE can achieve better BER performance than when using MMSE-CE and MMSE prediction.
space-timecoding is known to be a potential technique for improving the reliability of wireless communication over fading channels. In this paper, we investigate the performance of a space-time coded CDMA system in a...
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ISBN:
(纸本)9781467373104
space-timecoding is known to be a potential technique for improving the reliability of wireless communication over fading channels. In this paper, we investigate the performance of a space-time coded CDMA system in a fading channel. Although significant amount of related work is found in literature, not much reported work exists on the use of Gold codes as spreading sequences in such systems. In this paper, we investigate the performance of a space-timeblock-coded CDMA system for different chip lengths, ranging from 31-chip to 511-chip Gold codes. Results show that at low signal-to-noise ratio, the coding gain provided by the codes surpasses the diversity advantage provided by the use of the multiple antennas. The results also show that coding gain between no-diversity link and its Gold-coded counterpart is the same as that between the transmit-diversity link and its Gold-coded counterpart. The independence of the diversity advantage provided by multiple transmit antennas and the coding gain obtainable from the use of the spreading sequences enables the prediction of the performance of composite space-timeblock-coded CDMA systems.
This paper presents a MIMO adaptive beamforming in the MC-CDMA system. At the transmitter, a space-time block coding is concatenated to MC-CDMA modulation. At the receiver, an adaptive GSC beamformer is to filter the ...
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ISBN:
(纸本)9788955191356
This paper presents a MIMO adaptive beamforming in the MC-CDMA system. At the transmitter, a space-time block coding is concatenated to MC-CDMA modulation. At the receiver, an adaptive GSC beamformer is to filter the desired user and suppress interferences by beamspace processing. Combined with the space-time block coding, the smart antenna forms multi-mainbeams toward the desired user. The system performance is evaluated by illustrating the estimated DOAs, beampatterns, weight convergence and BERs in both the flat and frequency selective fadings.
Many generalized fading distributions are given in terms of special functions, complicating the analysis of wireless performance metrics. This paper presents novel approximations to the extended incomplete gamma funct...
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ISBN:
(纸本)9781479935130
Many generalized fading distributions are given in terms of special functions, complicating the analysis of wireless performance metrics. This paper presents novel approximations to the extended incomplete gamma function, the modified Bessel function of the second type, and the generalized Q-function. New simpler and unified form for the probability density function of the extended generalized-K (EGK) and M-N distributions is developed, avoiding complicated and computationally-expensive functions, e.g. Fox and Meijer-G. Based on the new unified PDF and the proposed approximations, we derive novel generic and unified expressions for the average bit error rate and average channel capacity for the recently introduced six most generalized fading channels, namely the EGK, the M-N, the a-η-μ, a-λ-μ, a-κ-μ, and a-λ-η-μ, including the generalized-K, generalized Nakagami-m, the a-μ, the η-μ, the λ-μ, the κ-μ, the Nakagami-Lognormal, the Weibull, the Rice, the Hoyt, the Maxwell and other fading scenarios as special cases. The Additive White Generalized Gaussian Noise (AWGGN) is considered as the noise model, that includes the AWGN, the Laplacian, the Gamma and the impulsive noise as special cases, being an application to the generalized Q-function approximation. Moreover, novel analysis for space-timeblock Codes in generalized-K fading is also developed as an application to the developed approximation of the modified Bessel function. The derived expressions are very simple and analytically traceable. Monte Carlo simulation and published work corroborate our obtained results.
In this paper, the bit error rate (BER) performance of multiuser multiple-input multiple-output (MIMO) systems over Rayleigh fading channels is studied, and corresponding asymptotic performance is analyzed. Based on t...
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ISBN:
(纸本)9781634392785
In this paper, the bit error rate (BER) performance of multiuser multiple-input multiple-output (MIMO) systems over Rayleigh fading channels is studied, and corresponding asymptotic performance is analyzed. Based on the asymptotic analysis at high signal to noise ratio (SNR), using the probability density functions (PDF) of the instantaneous channel power gain, the diversity gain and coding gain of the system with transmit antenna selection (TAS) scheme and space-time block coding (STBC) scheme are derived, respectively. As a result, the same full diversity gain is achieved for two transmission schemes, but their coding gains are different. With the obtained diversity gain and coding gain, the asymptotic BER expressions for two transmission schemes are respectively derived, which are in good agreement with the corresponding simulation results. The results show that the multiuser MIMO system with TAS scheme has better BER performance than that with STBC scheme due to higher coding gain.
A detector for space-time block coding is proposed to combat time-selective fading. To suppress both noise and interference, a minimum mean square error (MMSE) based detector is introduced for space-time block coding....
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A detector for space-time block coding is proposed to combat time-selective fading. To suppress both noise and interference, a minimum mean square error (MMSE) based detector is introduced for space-time block coding. It is shown by simulations that the proposed detector outperforms the conventional detectors when the channel is time-selective fading.
In this work, the use of space-time Codes in passive Radio Frequency IDentification (RFID) systems is explored;this is feasible whenever a tag possesses multiple antennas. Information is encoded across the multiple ta...
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In this work, the use of space-time Codes in passive Radio Frequency IDentification (RFID) systems is explored;this is feasible whenever a tag possesses multiple antennas. Information is encoded across the multiple tag antennas and received by an RFID reader, also typically equipped with multiple antennas. The nature of passive RFID induces a unique fading channel known as the dyadic backscatter channel, which differs statistically compared to the canonical Rayleigh fading channel. We introduce a modified dyadic channel for RFID backscatter that adequately captures the space-timecoding paradigm. We then propose known orthogonal space-time codes and derive an upper bound on the the pairwise error probability (PEP), leading to estimates of the (asymptotic) diversity order. Interestingly, the diversity order is shown to depend only on the number of tag antennas but not the number of receive antennas;the resultant performance trade-offs is discussed. Lastly, simulation of the symbol error rates for different channel configurations are conducted to validate the analysis.
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