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Full-Text Articles in Engineering
A Suboptimal Receiver With Turbo Block Coding For Ultra-Wideband Communications, Robert H. Morelos-Zaragoza, Timothy Becker, Sim Aquino
A Suboptimal Receiver With Turbo Block Coding For Ultra-Wideband Communications, Robert H. Morelos-Zaragoza, Timothy Becker, Sim Aquino
Faculty Publications
In this paper, the performance of adaptive equalization and turbo product coding is investigated for pulse-based UWB communications in short-range indoor environments. The sensitivity of adaptive LMS linear and nonlinear (decision-feedback) equalizers with respect to the number of training symbols and number of taps is considered. To reduce the error performance variation with respect to changing channel conditions, a turbo product code (TPC) with two component (31,26,3) Hamming codes is proposed. We report simulation results showing that channel coding not only improves error performance, but also reduces significantly the sensitivity of UWB systems in short-range indoor wireless communications.
Combined Beamforming And Space-Time Block Coding With A Sparse Array Antenna, Robert H. Morelos-Zaragoza, Mohammad Ghavami
Combined Beamforming And Space-Time Block Coding With A Sparse Array Antenna, Robert H. Morelos-Zaragoza, Mohammad Ghavami
Faculty Publications
We continue our investigation of joint beamforming and transmit diversity with space-time block coding. In particular, the performance of a four-element array antenna is considered, in the context of an indoor wireless communication system. The main contribution is to show that transmit diversity may be practically achieved, even with correlated beams produced by a sparse array antenna.
Multilevel Coded Modulation For Unequal Error Protection And Multistage Decoding—Part I: Symmetric Constellations, Robert H. Morelos-Zaragoza, Marc P. C. Fossorier, Shu Lin, Hideki Imai
Multilevel Coded Modulation For Unequal Error Protection And Multistage Decoding—Part I: Symmetric Constellations, Robert H. Morelos-Zaragoza, Marc P. C. Fossorier, Shu Lin, Hideki Imai
Faculty Publications
In this paper, theoretical upper bounds and computer simulation results on the error performance of multilevel block coded modulations for unequal error protection (UEP) and multistage decoding are presented. It is shown that nonstandard signal set partitionings and multistage decoding provide excellent UEP capabilities beyond those achievable with conventional coded modulation. The coding scheme is designed in such a way that the most important information bits have a lower error rate than other information bits. The large effective error coefficients, normally associated with standard mapping by set partitioning, are reduced by considering nonstandard partitionings of the underlying signal set. The …
Binary Multilevel Convolutional Codes With Unequal Error Protection Capabilities, Robert H. Morelos-Zaragoza, Hideki Imai
Binary Multilevel Convolutional Codes With Unequal Error Protection Capabilities, Robert H. Morelos-Zaragoza, Hideki Imai
Faculty Publications
Binary multilevel convolutional codes (CCs) with unequal error protection (UEP) capabilities are studied. These codes belong to the class of generalized concatenated (GC) codes. Binary CCs are used as outer codes. Binary linear block codes of short length, and selected subcodes in their two-way subcode partition chain, are used as inner codes. Multistage decodings are presented that use Viterbi decoders operating on trellises with similar structure to that of the constituent binary CCs. Simulation results of example binary two-level CC's are also reported.
On Block-Coded Modulation Using Unequal Error Protection Codes Over Rayleigh-Fading Channels, Robert H. Morelos-Zaragoza, Tadao Kasami, Shu Lin, Hideki Imai
On Block-Coded Modulation Using Unequal Error Protection Codes Over Rayleigh-Fading Channels, Robert H. Morelos-Zaragoza, Tadao Kasami, Shu Lin, Hideki Imai
Faculty Publications
This paper considers block-coded 8-phase-shift-keying (PSK) modulations for the unequal error protection (UEP) of information transmitted over Rayleigh-fading channels. Both conventional linear block codes and linear UEP (LUEP) codes are combined with a naturally labeled 8-PSK signal set, using the multilevel construction of Imai and Hirakawa (1977). Computer simulation results are presented showing that, over Rayleigh-fading channels, it is possible to improve the coding gain for the most significant bits with the use of binary LUEP codes as constituent codes, in comparison with using conventional binary linear codes alone.
Concatenated Multilevel Coded Modulation Schemes For Digital Satellite Broadcasting, Robert H. Morelos-Zaragoza, Hideki Imai
Concatenated Multilevel Coded Modulation Schemes For Digital Satellite Broadcasting, Robert H. Morelos-Zaragoza, Hideki Imai
Faculty Publications
The error performance of bandwith-efficient concatenated multilevel coded modulation (MCM) schemes for digital satellite broadcasting is analyzed. Nonstandard partitioning, multistage decoding, and outer Reed-Solomon (RS) codes are employed to provided unequal error protection capabilities.
Multilevel Block Coded Modulation With Unequal Error Protection, Robert H. Morelos-Zaragoza, Marc P. C. Fossorier, Shu Lin, Hideki Imai
Multilevel Block Coded Modulation With Unequal Error Protection, Robert H. Morelos-Zaragoza, Marc P. C. Fossorier, Shu Lin, Hideki Imai
Faculty Publications
Multilevel block coded modulation (BCM) schemes with unequal error protection (UEP) are investigated. These schemes are based on unconventional set partitions that greatly reduce the error coefficients associated with multi-stage decoding of conventional BCM, at the expense of smaller intra-set distances.
Coded Modulation For Satellite Broadcasting, Robert H. Morelos-Zaragoza, Oscar Y. Takeshita, Hideki Imai, Marc P. C. Fossorier, Shu Lin
Coded Modulation For Satellite Broadcasting, Robert H. Morelos-Zaragoza, Oscar Y. Takeshita, Hideki Imai, Marc P. C. Fossorier, Shu Lin
Faculty Publications
In this paper, three-level block coded 8-PSK modulations, suitable for satellite broadcasting of digital TV signals, are presented. A design principle to achieve unequal error protection is introduced. The coding scheme is designed in such a way that the information bits carrying the basic definition TV signal have a lower error rate than the high definition information bits. The large error coefficients, formally associated with standard mapping by set partitioning, are reduced by considering a nonstandard partition of an 8-PSK signal set. The bits-to-signal mapping induced by this partition allows the use of suboptimal low-complexity soft-decision decoding of binary block …
Multilevel Block Coded 8-Psk Modulations Using Unequal Error Protection Codes For The Rayleigh Fading Channel, Robert H. Morelos-Zaragoza, Tadeo Kamasi, Shu Lin
Multilevel Block Coded 8-Psk Modulations Using Unequal Error Protection Codes For The Rayleigh Fading Channel, Robert H. Morelos-Zaragoza, Tadeo Kamasi, Shu Lin
Faculty Publications
This paper introduces new block coded 8-PSK modulations with unequal error protection (UEP) capabilities for Rayleigh fading channels. The design of efficient block coded modulations (BCM) over 8-PSK signal sets, for the specific purpose of UEP, over Rayleigh fading channels is considered. UEP is desirable in communications systems where part of the source information is more important, or error sensitive, such as the transmission of coded speech and data broadcasting. The proposed block modulation codes are based on the multilevel construction of Imai and Hirakawa (1977). It is shown that the use of binary linear UEP (LUEP) codes as component …
Qpsk Block-Modulation Codes For Unequal Error Protection, Robert H. Morelos-Zaragoza, Shu Lin
Qpsk Block-Modulation Codes For Unequal Error Protection, Robert H. Morelos-Zaragoza, Shu Lin
Faculty Publications
Unequal error protection (UEP) codes find applications in broadcast channels, as well as in other digital communication systems, where messages have different degrees of importance. Binary linear UEP (LUEP) codes combined with a Gray mapped QPSK signal set are used to obtain new efficient QPSK block-modulation codes for unequal error protection. Several examples of QPSK modulation codes that have the same minimum squared Euclidean distance as the best QPSK modulation codes, of the same rate and length, are given. In the new constructions of QPSK block-modulation codes, even-length binary LUEP codes are used. Good even-length binary LUEP codes are obtained …
Block Qpsk Modulation Codes With Two Levels Of Error Protection, Robert H. Morelos-Zaragoza, Shu Lin
Block Qpsk Modulation Codes With Two Levels Of Error Protection, Robert H. Morelos-Zaragoza, Shu Lin
Faculty Publications
A class of block QPSK modulation codes for unequal error protection (UEP) is presented. These codes are particularly suitable either for broadcast channels or for communication systems where parts of the information messages are more important than others. An example of the latter is coded speech transmission. Not much is known on the application of block UEP codes in combined coding and modulation schemes. We exhibit a method to combine binary linear UEP (LUEP) block codes of even length, using a Gray mapping, with a QPSK signal set to construct efficient block QPSK modulation codes with nonuniform error protection capabilities …
Unequal Error Protection Qpsk Modulation Codes, Robert H. Morelos-Zaragoza, Shu Lin
Unequal Error Protection Qpsk Modulation Codes, Robert H. Morelos-Zaragoza, Shu Lin
Faculty Publications
The authors use binary linear UEP (LUEP) codes, in combination with a QPSK signal set and Gray mapping, to obtain new efficient block QPSK modulation codes with unequal minimum squared Euclidean distances. They give several examples of codes that have the same minimum squared Euclidean distance as the best QPSK modulation codes of the same rate and length. A new suboptimal two-stage soft-decision decoding is applied to LUEP QPSK modulation codes.