The Experts below are selected from a list of 20847 Experts worldwide ranked by ideXlab platform
Tomoaki Ohtsuki - One of the best experts on this subject based on the ideXlab platform.
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performance analysis of bp based algorithms for irregular low density parity check codes on fast Rayleigh Fading Channel
Vehicular Technology Conference, 2004Co-Authors: A Ohhashi, Tomoaki OhtsukiAbstract:In this paper, we analyze the performance of irregular low-density parity-check (LDPC) codes with three belief propagation (BP) based decoding algorithms, namely, the uniformly most powerful (UMP) BP-based algorithm, the normalized BP-based algorithm, and the offset BP-based algorithm on a fast Rayleigh Fading Channel by using density evolution (DE). We also optimize the code construction of the irregular LDPC codes with three BP-based algorithms, and determine optimum parameters for the normalized BP-based algorithm and the offset BP-based algorithm on the fast Rayleigh Fading Channel. From the numerical results, we show that the performance of the irregular LDPC codes with offset BP-based algorithm can be very close to that with the BP algorithm on the fast Rayleigh Fading Channel. We also show that the irregular LDPC codes with offset BP-based algorithm can achieve a very good trade-off between the performance and decoding complexity.
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regular low density parity check ldpc code with normalized and ump bp based algorithms on fast Rayleigh Fading Channel
Vehicular Technology Conference, 2004Co-Authors: A Ohhashi, Tomoaki OhtsukiAbstract:For the short regular LDPC codes, we derive the formula of the normalization factor (NF) theoretically by using the probability density function (pdf) of the initial likelihood information for the normalized BP-based algorithm. For the long regular LDPC codes, we derive the optimal NF for the normalized BP-based algorithm by using density evolution (DE). We also analyze the performance of the long regular LDPC codes with the UMP BP-based algorithm by using DE. From the numerical and simulation results, we show that the optimum NF for the short regular LDPC codes is different from that on the AWGN Channel. We also show that for the short regular LDPC codes, the normalized BP-based algorithm outperforms the UMP BP-based algorithm, and has the performance very close to those of the BP algorithm. Furthermore, for the long regular LDPC codes, we show that the normalized BP-based algorithm outperforms the BP algorithm and the UMP BP-based algorithm. Therefore, for the short and long regular codes, the normalized BP-based algorithm is shown to be suitable as the decoding algorithm on the fast Rayleigh Fading Channel.
A Ohhashi - One of the best experts on this subject based on the ideXlab platform.
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performance analysis of bp based algorithms for irregular low density parity check codes on fast Rayleigh Fading Channel
Vehicular Technology Conference, 2004Co-Authors: A Ohhashi, Tomoaki OhtsukiAbstract:In this paper, we analyze the performance of irregular low-density parity-check (LDPC) codes with three belief propagation (BP) based decoding algorithms, namely, the uniformly most powerful (UMP) BP-based algorithm, the normalized BP-based algorithm, and the offset BP-based algorithm on a fast Rayleigh Fading Channel by using density evolution (DE). We also optimize the code construction of the irregular LDPC codes with three BP-based algorithms, and determine optimum parameters for the normalized BP-based algorithm and the offset BP-based algorithm on the fast Rayleigh Fading Channel. From the numerical results, we show that the performance of the irregular LDPC codes with offset BP-based algorithm can be very close to that with the BP algorithm on the fast Rayleigh Fading Channel. We also show that the irregular LDPC codes with offset BP-based algorithm can achieve a very good trade-off between the performance and decoding complexity.
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regular low density parity check ldpc code with normalized and ump bp based algorithms on fast Rayleigh Fading Channel
Vehicular Technology Conference, 2004Co-Authors: A Ohhashi, Tomoaki OhtsukiAbstract:For the short regular LDPC codes, we derive the formula of the normalization factor (NF) theoretically by using the probability density function (pdf) of the initial likelihood information for the normalized BP-based algorithm. For the long regular LDPC codes, we derive the optimal NF for the normalized BP-based algorithm by using density evolution (DE). We also analyze the performance of the long regular LDPC codes with the UMP BP-based algorithm by using DE. From the numerical and simulation results, we show that the optimum NF for the short regular LDPC codes is different from that on the AWGN Channel. We also show that for the short regular LDPC codes, the normalized BP-based algorithm outperforms the UMP BP-based algorithm, and has the performance very close to those of the BP algorithm. Furthermore, for the long regular LDPC codes, we show that the normalized BP-based algorithm outperforms the BP algorithm and the UMP BP-based algorithm. Therefore, for the short and long regular codes, the normalized BP-based algorithm is shown to be suitable as the decoding algorithm on the fast Rayleigh Fading Channel.
Jeanclaude Belfiore - One of the best experts on this subject based on the ideXlab platform.
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on the complexity of ml lattice decoders for decoding linear full rate space time codes
International Symposium on Information Theory, 2003Co-Authors: G Rekaya, Jeanclaude BelfioreAbstract:We present a study and a comparison in terms of complexity of two ML-lattice decoders, the Sphere-Decoder (SD) and the Schnorr-Euchner de- coder (SE), when used to decode multi-antenna trans- mission schemes, using full rate space-time codes, over a Rayleigh Fading Channel.
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good lattice constellations for both Rayleigh Fading and gaussian Channels
IEEE Transactions on Information Theory, 1996Co-Authors: Joseph J Boutros, Emanuele Viterbo, C Rastello, Jeanclaude BelfioreAbstract:Recent work on lattices matched to the Rayleigh Fading Channel has shown how to construct good signal constellations with high spectral efficiency. We present a new family of lattice constellations, based on complex algebraic number fields, which have good performance on Rayleigh Fading Channels. Some of these lattices also present a reasonable packing density and thus may be used at the same time over a Gaussian Channel. Conversely, we show that particular versions of the best lattice packings (D/sub 4/, E/sub 6/, E/sub 8/, K/sub 12/, /spl Lambda//sub 16/, /spl Lambda//sub 24/), constructed from totally complex algebraic cyclotomic fields, present better performance over the Rayleigh Fading Channel. The practical interest in such signal constellations rises from the need to transmit information at high rates over both terrestrial and satellite links. Some further results in algebraic number theory related to ideals and their factorization are presented and the decoding algorithm used with these lattice constellations are illustrated together with practical results.
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constellations matched to the Rayleigh Fading Channel
IEEE Transactions on Information Theory, 1996Co-Authors: X Girand, Jeanclaude BelfioreAbstract:We introduce a new technique for designing signal sets matched to the Rayleigh Fading Channel, In particular, we look for n-dimensional (n/spl ges/2) lattices whose structure provides nth-order diversity. Our approach is based on a geometric formulation of the design problem which in turn can be solved by using a number-geometric approach. Specifically, a suitable upper bound on the pairwise error probability makes the design problem tantamount to the determination of what is called a critical lattice of the body S={x=(x/sub 1/, /spl middot//spl middot//spl middot/, x/sub n/)/spl isin/R/sup n/, |/spl Pi//sub i=1//sup n/x/sub i/|/spl les/1}. The lattices among which we search for an optimal solution are the standard embeddings in R/sup n/ of the number ring of some totally real number field of degree n over Q. Simulation results confirm that this approach yields lattices with considerable coding gains.
Monica Visintin - One of the best experts on this subject based on the ideXlab platform.
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Differential PSK block demodulation over a flat correlated Rayleigh-Fading Channel
IEEE Transactions on Communications, 1997Co-Authors: Monica VisintinAbstract:A technique is proposed to design a block demodulator for differential phase shift keying (DPSK) signals over a frequency flat correlated Rayleigh-Fading Channel. The technique allows one to drastically reduce the error floor typically present in the bit error rate (BER) curves at high signal to noise ratios (SNRs). The main idea is to use the Karhunen-Loeve expansion to have a more precise description of the Fading process at the receiver end.
Daoben Li - One of the best experts on this subject based on the ideXlab platform.
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Performance Analysis Framework of ML MIMO Receiver over Correlated Rayleigh Fading Channel
2006 IEEE International Conference on Communications, 2006Co-Authors: Gang Li, Xingqing Cheng, Daoben LiAbstract:In this paper, a novel performance analysis frame-work of Maximum Likelihood (ML) receiver for Vertical Bell Labs Layered Space-Time (V-BLAST) architecture over correlated Rayleigh Fading Channel is presented. Based on the statistical property of squared Euclidean distance, the exact expressions for Pairwise Error Probability (PEP) over transmit, receive, and joint correlated Fading Channel are derived. The approximate expression of the PEPs for high signal-to-noise ration (SNR) region is used to quantitatively analyze the loss of the diversity order and the penalty of SNR. Three interesting results of this analysis are: 1) the loss caused by transmit and receive correlation is independent. 2) the transmit correlation has no impact on the diversity order, and the loss of SNR caused by transmit correlation is determined by the transmit correlation matrix and modulation scheme. 3) the loss of diversity order due to receive correlation is equals to the difference of the numbers of receiver antenna and the rank of receive correlation matrix, under the assumption that the receive correlation matrix has full rank, the penalty of SNR is jointly determined by the determinant of the receive correlation matrix and the number of receive antenna. Simulation results are given to corroborate the theoretical analysis.
