The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Essam Sourour - One of the best experts on this subject based on the ideXlab platform.
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Codebook-Based Precoding for generalized spatial modulation with diversity
EURASIP Journal on Wireless Communications and Networking, 2019Co-Authors: Essam SourourAbstract:This paper investigates Codebook-Based Precoding for spatial modulation (SM) and generalized spatial modulation (GSM) systems. Codebook-Based Precoding allows the system to dispense with full channel state information at the transmitter (CSIT). This considerably reduces the feedback overhead. Phase-only Codebooks with systematic structure are investigated since they avoid increasing the peak to average power ratio of the transmitted signal. It is shown that the proposed phase-only Codebooks yield equivalent performance to published Codebooks that involve gain and phase. In addition, a gain-only Codebook is designed to supplement the phase-only Codebook and reduce the bit error rate (BER) further. We also compare the performance with the Grassmannian Codebooks which are proposed for other multiple-in-multiple-out (MIMO) systems. In GSM systems, several antennas are simultaneously active as a transmit antenna combination (TAC). The BER performance of unprecoded GSM systems is typically inferior to SM systems due to correlation among TACs. However, with Codebook Precoding, this effect is mitigated, and the performance of the GSM system becomes superior to the SM system. We investigate Codebook Precoding for GSM systems where Precoding is performed per-TAC or per-antenna. Moreover, we investigate the GSM system where the TACs are selected adaptively Based on the achievable benefit from Codebook Precoding. Using computer simulation, it is shown that the performance of the proposed Codebooks is very promising in both SM and GSM systems. Per-antenna Precoding is superior to per-TAC Precoding. Adaptive TACs selection further improves performance.
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Codebook Based Precoding for spatial modulation
Vehicular Technology Conference, 2019Co-Authors: Essam SourourAbstract:This paper investigates Codebook-Based Precoding for spatial modulation (SM) systems to improve the performance, reduce the feedback overhead and dispense with Channel State Information at the Transmitter (CSIT). Phase-only Codebook with systematic structure, that is independent of the CSIT, is proposed. This Codebook could meet published performance of SM Codebook Precoding with same or lower feedback overhead and simpler implementation. When supplemented with the proposed gain-only Codebook, the performance improves further at the cost of small additional feedback overhead.
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VTC Spring - Codebook Based Precoding for Spatial Modulation
2019 IEEE 89th Vehicular Technology Conference (VTC2019-Spring), 2019Co-Authors: Essam SourourAbstract:This paper investigates Codebook-Based Precoding for spatial modulation (SM) systems to improve the performance, reduce the feedback overhead and dispense with Channel State Information at the Transmitter (CSIT). Phase-only Codebook with systematic structure, that is independent of the CSIT, is proposed. This Codebook could meet published performance of SM Codebook Precoding with same or lower feedback overhead and simpler implementation. When supplemented with the proposed gain-only Codebook, the performance improves further at the cost of small additional feedback overhead.
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performance improvement of space shift keying mimo systems with orthogonal Codebook Based phase rotation Precoding
Wireless Communications and Mobile Computing, 2017Co-Authors: Mohammed Alansi, S A Aljunid, Essam SourourAbstract:This paper considers Codebook-Based Precoding for Space Shift Keying (SSK) modulation MIMO system. Codebook-Based Precoding avoids the necessity for full knowledge of Channel State Information (CSI) at the transmitter and alleviates the complexity of generating a CSI-optimized precoder. The receiver selects the codeword that maximizes the Minimum Euclidean Distance (MED) of the received constellation and feeds back its index to the transmitter. In this paper, we first develop a new accurate closed-form Bit Error Rate (BER) for SSK without Precoding. Then, we investigate several phase-rotation Codebooks with quantized set of phases and systematic structure. Namely, we investigate the Full-Combination, Walsh-Hadamard, Quasi-Orthogonal Sequences, and Orthogonal Array Testing Codebooks. In addition, since the size of the Full-Combination Codebook may be large, we develop an iterative search method for fast selection of its best codeword. The proposed Codebooks significantly improve the BER performance in Rayleigh and Nakagami fading channels, even at high spatial correlation among transmit antennas and CSI estimation error. Moreover, we show that only four phases are sufficient and further phase granularity does yield significant gain. This avoids hardware multiplication during searching the Codebook and applying the codeword.
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phase rotation Codebook Precoding for space shift keying mimo systems
International Conference on Mobile and Wireless Technology, 2017Co-Authors: Mohammed Alansi, S A Aljunid, Essam SourourAbstract:Transmit Precoding (TPC) techniques Based on maximizing the Minimum Euclidean Distance (MED) of the received constellation have been proposed to improve the performance of Space Shift Keying (SSK) MIMO systems. These methods have limitations, including the necessity of full Channel State Information (CSI) at the transmitter, high complexity since they generate arbitrary precoders, and the requirement of infinite rate feedback channel. On the other hand, Codebook Based Precoding approach have the competency to tackle these difficulties. Hence, this paper proposes Full-Combination (FC) Codebook with a systematic structure constructed Based on Phase Rotation Precoding (PRP) where the CSI is known to the receiver only. Also, two effective Codebooks called Factorized Full-Combinations (FFC) and Statistically Filtered Full-Combinations (SFF) are designed to solve the exhaustive search problem in FC Codebook needed to find the best codeword that maximizes MED. Results illustrate the considerable performance gain achieved through applying the FC Codebook. In addition, we show the capability of FFC and SFF Codebooks to reduce the complexity and provide almost the same BER as FC Codebook.
H Taoka - One of the best experts on this subject based on the ideXlab platform.
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WCSP - Investigation on transmit and receiver diversity gains considering channel estimation error for uplink DFT-precoded OFDMA
2011 International Conference on Wireless Communications and Signal Processing (WCSP), 2011Co-Authors: Lianjun Deng, H Taoka, Teruo Kawamura, Mamoru SawahashiAbstract:Transmit diversity associated with receiver diversity is very effective in improving the bit error rate or block error rate (BLER) performance as a Rank-1 transmission scheme. However, it is not easy to rely on theoretical analysis to analyze transmit and receiver diversity gains considering channel coding, frequency diversity through a wider transmission bandwidth, and channel estimation error in Discrete Fourier Transform (DFT)-precoded Orthogonal Frequency Division Multiple Access (OFDMA) using a frequency domain equalizer (FDE). Therefore, this paper investigates the gains of transmit diversity and receiver diversity considering channel estimation error for uplink DFT-precoded OFDMA. More specifically, we clarify the gains from open-loop (OL) transmit diversity using space-time block code (STBC) Based coding and closed-loop (CL) transmit diversity with Codebook Based Precoding at a set of user equipment (UE) assuming receiver diversity with the maximum of 12 antennas at a base station (BS) Based on link-level computer simulations. Then, we clarify the numbers of transmit and receiver diversity branches, which provide distinct gains in terms of the BLER improvement.
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VTC Fall - Effect of Intra-Subframe Frequency Hopping on Closed-Loop Type Transmit Diversity with Precoding for Uplink DFT-Precoded OFDMA
2011 IEEE Vehicular Technology Conference (VTC Fall), 2011Co-Authors: Lianjun Deng, H Taoka, Teruo Kawamura, Mamoru SawahashiAbstract:This paper proposes applying intra-subframe frequency hopping (FH) to closed-loop (CL) type transmit diversity using Codebook Based Precoding for a shared channel carrying user traffic data in the uplink discrete Fourier transform (DFT)-precoded Orthogonal Frequency Division Multiple Access (OFDMA). In the paper, we present two types of Precoding schemes associated with intra-subframe FH: individual Precoding vector selection between 2 slots where a 1-msec subframe comprises 2 slots among the reduced Precoding Codebooks, and common Precoding vector selection between 2 slots. We investigate the effect of intra-subframe FH on the CL type transmit diversity with Precoding in terms of the block error rate (BLER) performance while maintaining the same number of feedback bits required for notification of the selected Precoding vector as that for CL type Precoding Based transmit diversity without FH. Computer simulation results show that CL type transmit diversity with Precoding using intra-subframe FH is very effective in reducing the required average received signal-to-noise power ratio (SNR) when the fading maximum Doppler frequency, fD, is higher than approximately 50 Hz both for 2- and 4-antenna transmission in the uplink DFT-precoded OFDMA.
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A Multi-Stage Hybrid Scheduler for Codebook-Based MU-MIMO System
IEICE Transactions on Communications, 2009Co-Authors: Jingxiu Liu, Xiaoming She, Lan Chen, H TaokaAbstract:In this paper, we propose a multi-stage hybrid scheduling scheme for Codebook-Based Precoding systems, which provides a framework to apply different scheduling criterions at different scheduling stages for selecting user equipment (UEs). Numerical simulation results show that the proposed scheme effectively fills the performance gap between maximum carrier-to-interference (Max C/I) power ratio and Proportional Fairness (PF) methods, and provides an important means at the media access control (MAC) layer to lever between aggregate cellular throughput and geometry-specific per-user fairness, in order to meet the requirements of more precise quality of service (QoS) provision for future mobile communication systems.
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Comparisons between Common and Dedicated Reference Signals for MIMO Multiplexing Using Precoding in Evolved UTRA Downlink
IEICE Transactions on Communications, 2009Co-Authors: H Taoka, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru SawahashiAbstract:This paper presents comparisons between common and dedicated reference signals (RSs) for channel estimation in MIMO multiplexing using Codebook-Based Precoding for orthogonal frequency division multiplexing (OFDM) radio access in the Evolved UTRA downlink with frequency division duplexing (FDD). We clarify the best RS structure for Precoding-Based MIMO multiplexing Based on comparisons of the structures in terms of the achievable throughput taking into account the overhead of the common and dedicated RSs and the Precoding matrix indication (PMI) signal. Based on extensive simulations on the throughput in 2-by-2 and 4-by-4 MIMO multiplexing with Precoding, we clarify that channel estimation Based on common RSs multiplied with the Precoding matrix indicated by the PMI signal achieves higher throughput compared to that using dedicated RSs irrespective of the number of spatial multiplexing streams when the number of available Precoding matrices, i.e., the Codebook size, is less than approximately 16 and 32 for 2-by-2 and 4-by-4 MIMO multiplexing, respectively.
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a multi stage hybrid scheduler for Codebook Based Precoding system
Wireless Communications and Networking Conference, 2008Co-Authors: Jingxiu Liu, Xiaoming She, Lan Chen, H TaokaAbstract:Significant throughput gains can be obtained in multi-user wireless system by exploiting the combination of multi-user scheduling in media access control (MAC) layer and MIMO spatial multiplexing using Precoding in physical (PHY) layer. In this paper, we propose a multi-stage hybrid scheduling scheme for Codebook-Based Precoding system, which applies different scheduling methods at different scheduling stages for selecting user equipments (UEs). In detail, we employ different scheduling algorithms when the appropriate UE or UE sets are selected within the same Precoding vector, within the same Precoding matrix, and within the Codebook, respectively, so that we could finely adjust the balance between capacity and fairness. Computer simulation results show that the proposed scheme effectively fills the performance gap between pure maximum carrier-to-interference (C/I) power ratio and pure proportional fairness (PF) methods, and provides an important means at the MAC layer to lever between aggregate cellular throughput and geometry-specific per-user fairness, in order to meet the requirements of more precise quality of service (QoS) provision for future mobile communication systems.
Ping Zhang - One of the best experts on this subject based on the ideXlab platform.
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Unitary Space Vector Quantization Codebook Design for Precoding MIMO System
IEICE Transactions on Communications, 2008Co-Authors: Ping ZhangAbstract:In a Codebook Based Precoding MIMO system, the Precoding Codebook significantly determines the system performance. Consequently, it is crucial to design the Precoding Codebook, which is related to the channel fading, antenna number, spatial correlation etc. So specific channel conditions correspond to respective optimum Codebooks. In this paper, in order to obtain the optimum Codebooks, a universal unitary space vector quantization (USVQ) Codebook design criterion is provided, which can design the optimum Codebooks for various fading and spatial correlated channels with arbitrary antenna configurations. Furthermore, the unitary space K-mean (USK) algorithm is also proposed to generate the USVQ Codebook, which is iterative and convergent. Simulations show that the capacities of the Precoding MIMO schemes using the USVQ Codebooks are very close to those of the ideal Precoding cases and outperform those of the schemes using the traditional Grassmannian Codebooks and the 3GPP LTE DFT (discrete Fourier transform) Codebooks.
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VTC Spring - Universal Unitary Space Vector Quantization Codebook Design for Precoding MIMO System under Spatial Correlated Channel
VTC Spring 2008 - IEEE Vehicular Technology Conference, 2008Co-Authors: Ping ZhangAbstract:In Codebook Based Precoding MIMO system, the Precoding Codebook affects the system performance remarkably. Consequently, it is a crucial technology to design the optimum Codebook for Precoding MIMO system. Codebook design is related to the channel fading, antenna number, spatial correlation etc. So specific distributed channel corresponds to respective optimum Codebook. In this paper, in order to design the optimum Codebooks for the Precoding MIMO system, a universal unitary space vector quantization (USVQ) Codebook design criterion is provided, which can design the optimum Codebooks for various spatial correlated channels with arbitrary antenna configurations. The unitary space K-mean(USK) algorithm is also provided to generate the USVQ Codebook, which is iterative and convergent. Simulations show that the capacities of the Precoding MIMO schemes using the USVQ Codebooks are very close to those of the ideal Precoding cases and outperform those of the schemes using the traditional Grassmannian Codebooks.
Mamoru Sawahashi - One of the best experts on this subject based on the ideXlab platform.
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VTC Fall - Effect of Intra-Subframe Frequency Hopping on Closed-Loop Type Transmit Diversity with Precoding for Uplink DFT-Precoded OFDMA
2011 IEEE Vehicular Technology Conference (VTC Fall), 2011Co-Authors: Lianjun Deng, H Taoka, Teruo Kawamura, Mamoru SawahashiAbstract:This paper proposes applying intra-subframe frequency hopping (FH) to closed-loop (CL) type transmit diversity using Codebook Based Precoding for a shared channel carrying user traffic data in the uplink discrete Fourier transform (DFT)-precoded Orthogonal Frequency Division Multiple Access (OFDMA). In the paper, we present two types of Precoding schemes associated with intra-subframe FH: individual Precoding vector selection between 2 slots where a 1-msec subframe comprises 2 slots among the reduced Precoding Codebooks, and common Precoding vector selection between 2 slots. We investigate the effect of intra-subframe FH on the CL type transmit diversity with Precoding in terms of the block error rate (BLER) performance while maintaining the same number of feedback bits required for notification of the selected Precoding vector as that for CL type Precoding Based transmit diversity without FH. Computer simulation results show that CL type transmit diversity with Precoding using intra-subframe FH is very effective in reducing the required average received signal-to-noise power ratio (SNR) when the fading maximum Doppler frequency, fD, is higher than approximately 50 Hz both for 2- and 4-antenna transmission in the uplink DFT-precoded OFDMA.
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WCSP - Investigation on transmit and receiver diversity gains considering channel estimation error for uplink DFT-precoded OFDMA
2011 International Conference on Wireless Communications and Signal Processing (WCSP), 2011Co-Authors: Lianjun Deng, H Taoka, Teruo Kawamura, Mamoru SawahashiAbstract:Transmit diversity associated with receiver diversity is very effective in improving the bit error rate or block error rate (BLER) performance as a Rank-1 transmission scheme. However, it is not easy to rely on theoretical analysis to analyze transmit and receiver diversity gains considering channel coding, frequency diversity through a wider transmission bandwidth, and channel estimation error in Discrete Fourier Transform (DFT)-precoded Orthogonal Frequency Division Multiple Access (OFDMA) using a frequency domain equalizer (FDE). Therefore, this paper investigates the gains of transmit diversity and receiver diversity considering channel estimation error for uplink DFT-precoded OFDMA. More specifically, we clarify the gains from open-loop (OL) transmit diversity using space-time block code (STBC) Based coding and closed-loop (CL) transmit diversity with Codebook Based Precoding at a set of user equipment (UE) assuming receiver diversity with the maximum of 12 antennas at a base station (BS) Based on link-level computer simulations. Then, we clarify the numbers of transmit and receiver diversity branches, which provide distinct gains in terms of the BLER improvement.
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Comparisons between Common and Dedicated Reference Signals for MIMO Multiplexing Using Precoding in Evolved UTRA Downlink
IEICE Transactions on Communications, 2009Co-Authors: H Taoka, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru SawahashiAbstract:This paper presents comparisons between common and dedicated reference signals (RSs) for channel estimation in MIMO multiplexing using Codebook-Based Precoding for orthogonal frequency division multiplexing (OFDM) radio access in the Evolved UTRA downlink with frequency division duplexing (FDD). We clarify the best RS structure for Precoding-Based MIMO multiplexing Based on comparisons of the structures in terms of the achievable throughput taking into account the overhead of the common and dedicated RSs and the Precoding matrix indication (PMI) signal. Based on extensive simulations on the throughput in 2-by-2 and 4-by-4 MIMO multiplexing with Precoding, we clarify that channel estimation Based on common RSs multiplied with the Precoding matrix indicated by the PMI signal achieves higher throughput compared to that using dedicated RSs irrespective of the number of spatial multiplexing streams when the number of available Precoding matrices, i.e., the Codebook size, is less than approximately 16 and 32 for 2-by-2 and 4-by-4 MIMO multiplexing, respectively.
Lianjun Deng - One of the best experts on this subject based on the ideXlab platform.
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WCSP - Investigation on transmit and receiver diversity gains considering channel estimation error for uplink DFT-precoded OFDMA
2011 International Conference on Wireless Communications and Signal Processing (WCSP), 2011Co-Authors: Lianjun Deng, H Taoka, Teruo Kawamura, Mamoru SawahashiAbstract:Transmit diversity associated with receiver diversity is very effective in improving the bit error rate or block error rate (BLER) performance as a Rank-1 transmission scheme. However, it is not easy to rely on theoretical analysis to analyze transmit and receiver diversity gains considering channel coding, frequency diversity through a wider transmission bandwidth, and channel estimation error in Discrete Fourier Transform (DFT)-precoded Orthogonal Frequency Division Multiple Access (OFDMA) using a frequency domain equalizer (FDE). Therefore, this paper investigates the gains of transmit diversity and receiver diversity considering channel estimation error for uplink DFT-precoded OFDMA. More specifically, we clarify the gains from open-loop (OL) transmit diversity using space-time block code (STBC) Based coding and closed-loop (CL) transmit diversity with Codebook Based Precoding at a set of user equipment (UE) assuming receiver diversity with the maximum of 12 antennas at a base station (BS) Based on link-level computer simulations. Then, we clarify the numbers of transmit and receiver diversity branches, which provide distinct gains in terms of the BLER improvement.
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VTC Fall - Effect of Intra-Subframe Frequency Hopping on Closed-Loop Type Transmit Diversity with Precoding for Uplink DFT-Precoded OFDMA
2011 IEEE Vehicular Technology Conference (VTC Fall), 2011Co-Authors: Lianjun Deng, H Taoka, Teruo Kawamura, Mamoru SawahashiAbstract:This paper proposes applying intra-subframe frequency hopping (FH) to closed-loop (CL) type transmit diversity using Codebook Based Precoding for a shared channel carrying user traffic data in the uplink discrete Fourier transform (DFT)-precoded Orthogonal Frequency Division Multiple Access (OFDMA). In the paper, we present two types of Precoding schemes associated with intra-subframe FH: individual Precoding vector selection between 2 slots where a 1-msec subframe comprises 2 slots among the reduced Precoding Codebooks, and common Precoding vector selection between 2 slots. We investigate the effect of intra-subframe FH on the CL type transmit diversity with Precoding in terms of the block error rate (BLER) performance while maintaining the same number of feedback bits required for notification of the selected Precoding vector as that for CL type Precoding Based transmit diversity without FH. Computer simulation results show that CL type transmit diversity with Precoding using intra-subframe FH is very effective in reducing the required average received signal-to-noise power ratio (SNR) when the fading maximum Doppler frequency, fD, is higher than approximately 50 Hz both for 2- and 4-antenna transmission in the uplink DFT-precoded OFDMA.