The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Takaaki Hasegawa - One of the best experts on this subject based on the ideXlab platform.
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theoretical analysis of m ary ss communication systems using racing counters and a Hadamard Matrix
IEEE Journal on Selected Areas in Communications, 1996Co-Authors: Kouji Ohuchi, Hiromasa Habuchi, Takaaki HasegawaAbstract:The performance of M-ary spread spectrum (M-ary/SS) communication systems is discussed. Firstly, the initial acquisition time is evaluated. Secondly, the retention time, which is the average number of frames holding correct frame timing, and the recovery time, which is the average number of frames required to establish synchronization, are derived. Lastly, the bit-error rate (BER) performance is evaluated. M-ary/SS communication systems, which have more than one spreading code, can improve the BER performance under conditions in which there is additive white Gaussian noise (AWGN). However, the synchronization of M-ary/SS communication systems is difficult because they have several spreading codes. The frame synchronization method uses a Hadamard Matrix and "racing counters." As a result, the retention time becomes longer than the recovery time when the size of the lower counter differs greatly from that of the upper counter in the racing counters. Then the BER gets close to the performance which is achieved under complete synchronization.
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Theoretical Analysis of M-arylSS Communication Systems Using Racing Counters and a Hadamard Matrix
1996Co-Authors: Kouji Ohuchi, Hiromasa Habuchi, Takaaki HasegawaAbstract:Abstruct- In this paper, performance of M-ary spread spectrum (M-arylSS) communication systems is discussed. Firstly, the initial acquisition time is evaluated. Secondly, retention time, which is the average number of frames holding correct frame timing, and recovery time, which is the average number of frames required to establish synchronization, are derived. Lastly, bit-error rate (BER) performance is evaluated. M-arylSS communication systems, which have more than one spreading code, can improve BER performance under conditions in which there is additive white Gaussian noise (AWGN). However, the synchronization of M-ary/SS communication systems is difficult because they have several spreading codes. The frame synchronization method which is used in this paper uses a Hadamard Matrix and “racing counters.” As a result, the retention time becomes longer than the recovery time when the size of the lower counter differs greatly from that of the upper counter in the racing counters. Then BER gets close to the performance which is achieved under the complete synchronization.
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Theoretical analysis of M-ary/SS communication systems using racing counters and a Hadamard Matrix
IEEE Journal on Selected Areas in Communications, 1996Co-Authors: Kouji Ohuchi, Hiromasa Habuchi, Takaaki HasegawaAbstract:The performance of M-ary spread spectrum (M-ary/SS) communication systems is discussed. Firstly, the initial acquisition time is evaluated. Secondly, the retention time, which is the average number of frames holding correct frame timing, and the recovery time, which is the average number of frames required to establish synchronization, are derived. Lastly, the bit-error rate (BER) performance is evaluated. M-ary/SS communication systems, which have more than one spreading code, can improve the BER performance under conditions in which there is additive white Gaussian noise (AWGN). However, the synchronization of M-ary/SS communication systems is difficult because they have several spreading codes. The frame synchronization method uses a Hadamard Matrix and "racing counters." As a result, the retention time becomes longer than the recovery time when the size of the lower counter differs greatly from that of the upper counter in the racing counters. Then the BER gets close to the performance which is achieved under complete synchronization.
Saleh M. Al-qaraawy - One of the best experts on this subject based on the ideXlab platform.
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IPI Removing by Using Reference Sign/N-ary Orthogonal Coded/Balanced TR-UWB Receiver for WPAN Based on Hadamard Matrix
Al-Nahrain Journal for Engineering Sciences, 2009Co-Authors: Saleh M. Al-qaraawyAbstract:IR UWB system has been proposed as a promising physical layer candidate for indoor wireless communications, because it offers very fine time resolution and multipath resolvability. Inter pulse interference (IPI) is one important challenge related to the transmit reference (TR) IR UWB receiver. In this paper, an attempt to completely remove the IPI problem in TR with increasing the data rate. This is achieved by using orthogonal codes generated from modified version of Hadamard Matrix via the application of the reference sign technique, i.e., by modulating the reference pulse besides the already data modulated.
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Multi-Delay Biorthogonal Coded/Balanced TR-UWB Receiver for WPAN Based on Hadamard Matrix
2008Co-Authors: Saleh M. Al-qaraawyAbstract:Impulse radio ultra wideband (IR-UWB) communication is becoming an important technology for future Wireless Personal Area Networks (WPANs). One of the critical challenges in IR-UWB system design is the inter-pulse interference (IPI). A Transmit-reference (TR) receiver is proposed to completely remove the IPI especially at low input frame energy-to- noise-ratio ( E f/No) values. This receiver is based on the using of a modified version of Hadamard Matrix to yield a biorthogonal coded words instead of orthogonal ones. On the other hand, from the complexity view, the proposed TR receiver in this paper has high complexity as compared with the balanced coded orthogonal TR receiver proposed recently but it outperforms it.
Kouji Ohuchi - One of the best experts on this subject based on the ideXlab platform.
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theoretical analysis of m ary ss communication systems using racing counters and a Hadamard Matrix
IEEE Journal on Selected Areas in Communications, 1996Co-Authors: Kouji Ohuchi, Hiromasa Habuchi, Takaaki HasegawaAbstract:The performance of M-ary spread spectrum (M-ary/SS) communication systems is discussed. Firstly, the initial acquisition time is evaluated. Secondly, the retention time, which is the average number of frames holding correct frame timing, and the recovery time, which is the average number of frames required to establish synchronization, are derived. Lastly, the bit-error rate (BER) performance is evaluated. M-ary/SS communication systems, which have more than one spreading code, can improve the BER performance under conditions in which there is additive white Gaussian noise (AWGN). However, the synchronization of M-ary/SS communication systems is difficult because they have several spreading codes. The frame synchronization method uses a Hadamard Matrix and "racing counters." As a result, the retention time becomes longer than the recovery time when the size of the lower counter differs greatly from that of the upper counter in the racing counters. Then the BER gets close to the performance which is achieved under complete synchronization.
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Theoretical Analysis of M-arylSS Communication Systems Using Racing Counters and a Hadamard Matrix
1996Co-Authors: Kouji Ohuchi, Hiromasa Habuchi, Takaaki HasegawaAbstract:Abstruct- In this paper, performance of M-ary spread spectrum (M-arylSS) communication systems is discussed. Firstly, the initial acquisition time is evaluated. Secondly, retention time, which is the average number of frames holding correct frame timing, and recovery time, which is the average number of frames required to establish synchronization, are derived. Lastly, bit-error rate (BER) performance is evaluated. M-arylSS communication systems, which have more than one spreading code, can improve BER performance under conditions in which there is additive white Gaussian noise (AWGN). However, the synchronization of M-ary/SS communication systems is difficult because they have several spreading codes. The frame synchronization method which is used in this paper uses a Hadamard Matrix and “racing counters.” As a result, the retention time becomes longer than the recovery time when the size of the lower counter differs greatly from that of the upper counter in the racing counters. Then BER gets close to the performance which is achieved under the complete synchronization.
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Theoretical analysis of M-ary/SS communication systems using racing counters and a Hadamard Matrix
IEEE Journal on Selected Areas in Communications, 1996Co-Authors: Kouji Ohuchi, Hiromasa Habuchi, Takaaki HasegawaAbstract:The performance of M-ary spread spectrum (M-ary/SS) communication systems is discussed. Firstly, the initial acquisition time is evaluated. Secondly, the retention time, which is the average number of frames holding correct frame timing, and the recovery time, which is the average number of frames required to establish synchronization, are derived. Lastly, the bit-error rate (BER) performance is evaluated. M-ary/SS communication systems, which have more than one spreading code, can improve the BER performance under conditions in which there is additive white Gaussian noise (AWGN). However, the synchronization of M-ary/SS communication systems is difficult because they have several spreading codes. The frame synchronization method uses a Hadamard Matrix and "racing counters." As a result, the retention time becomes longer than the recovery time when the size of the lower counter differs greatly from that of the upper counter in the racing counters. Then the BER gets close to the performance which is achieved under complete synchronization.
Han Hai - One of the best experts on this subject based on the ideXlab platform.
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A Novel Generalized Butson-type Hadamard Matrix-Aided Space Shift Keying Modulation Scheme
2019 IEEE 2nd International Conference on Automation Electronics and Electrical Engineering (AUTEEE), 2019Co-Authors: Jie Zhu, Han Hai, Shuai Wang, Ping WangAbstract:Space shift keying (SSK) and its generalized form (namely, generalized SSK or GSSK) as energy-efficient technique, which only exploit spatial domain to convey information, present a potential option for the next generation modulation research. In this paper, we propose a novel modulation scheme called Generalized Butson-type Hadamard Matrix-aided Space Shift Keying (GBHSSK), which introduces Butson-type Hadamard Matrix with an arbitrary order for the symbol vector mapping operation. By establishing mapping between the Matrix dimension and the number of activated antennas, the proposed scheme can activate any number of antennas to provide rich flexibility in system design. In GBHSSK, partial information bits are encoded in the selected symbol vectors to achieve higher spectral efficiency. Because of the inherent orthogonality between the columns of Butson-type Hadamard Matrix, GBHSSK also has better adaptability to the fast fading channels without introducing the inter symbol interference (ISI). To support our results, we derive the theoretical upper bound on bit error rate(BER) for GBHSSK system. The Monte Carlo simulation results demonstrate that for the same transmission the GBHSSK system can achieve better BER performance than the existing variants of spatial modulation(SM).
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complex Hadamard Matrix aided generalized space shift keying modulation
IEEE Access, 2017Co-Authors: Han Hai, Xueqin Jiang, Wei Duan, Moon Ho Lee, Yongchae JeongAbstract:In this paper, we present a complex Hadamard Matrix-aided generalized space shift keying (HSSK) modulation scheme, which introduces complex-Hadamard-based signal vectors at the transmitter to provide higher spectrum efficiency than generalized space shift keying (GSSK). It also has lower maximum-likelihood detection complexity than the multiple active spatial modulation (MA-SM) and generalized spatial modulation (GSM) systems due to the corresponding fast complex Hadamard transform at the receiver. Based on the Lee distance of our signal vectors, we provide an optimized mapping between our data bits and signal vectors. We also analyze the upper bound on the average bit error rate of our HSSK system, which agrees well with the simulation results. Finally, the performance of HSSK is compared with MA-SM, GSM, and GSSK systems through Monte Carlo simulations. It is shown that for the same transmission rate the HSSK system performs better than the GSM, MA-SM, and GSSK systems.
Ian M. Wanless - One of the best experts on this subject based on the ideXlab platform.
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Trades in complex Hadamard matrices
arXiv: Combinatorics, 2015Co-Authors: Padraig Ó Catháin, Ian M. WanlessAbstract:A trade in a complex Hadamard Matrix is a set of entries which can be changed to obtain a different complex Hadamard Matrix. We show that in a real Hadamard Matrix of order $n$ all trades contain at least $n$ entries. We call a trade rectangular if it consists of a subMatrix that can be multiplied by some scalar $c \neq 1$ to obtain another complex Hadamard Matrix. We give a characterisation of rectangular trades in complex Hadamard matrices of order $n$ and show that they all contain at least $n$ entries. We conjecture that all trades in complex Hadamard matrices contain at least $n$ entries.
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Trades in complex Hadamard matrices
Algebraic Design Theory and Hadamard Matrices, 2015Co-Authors: Padraig Ó Catháin, Ian M. WanlessAbstract:A trade in a complex Hadamard Matrix is a set of entries which can be changed to obtain a different complex Hadamard Matrix. We show that in a real Hadamard Matrix of order n all trades contain at least n entries. We call a trade rectangular if it consists of a subMatrix that can be multiplied by some scalar c ≠ 1 to obtain another complex Hadamard Matrix. We give a characterisation of rectangular trades in complex Hadamard matrices of order n and show that they all contain at least n entries. We conjecture that all trades in complex Hadamard matrices contain at least n entries.
