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94
Spacetime codes for high data rate wireless communication: Performance criterion and code construction
 IEEE TRANS. INFORM. THEORY
, 1998
"... We consider the design of channel codes for improving the data rate and/or the reliability of communications over fading channels using multiple transmit antennas. Data is encoded by a channel code and the encoded data is split into n streams that are simultaneously transmitted using n transmit ant ..."
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Cited by 1765 (28 self)
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We consider the design of channel codes for improving the data rate and/or the reliability of communications over fading channels using multiple transmit antennas. Data is encoded by a channel code and the encoded data is split into n streams that are simultaneously transmitted using n transmit antennas. The received signal at each receive antenna is a linear superposition of the n transmitted signals perturbed by noise. We derive performance criteria for designing such codes under the assumption that the fading is slow and frequency nonselective. Performance is shown to be determined by matrices constructed from pairs of distinct code sequences. The minimum rank among these matrices quantifies the diversity gain, while the minimum determinant of these matrices quantifies the coding gain. The results are then extended to fast fading channels. The design criteria are used to design trellis codes for high data rate wireless communication. The encoding/decoding complexity of these codes is comparable to trellis codes employed in practice over Gaussian channels. The codes constructed here provide the best tradeoff between data rate, diversity advantage, and trellis complexity. Simulation results are provided for 4 and 8 PSK signal sets with data rates of 2 and 3 bits/symbol, demonstrating excellent performance that is within 2–3 dB of the outage capacity for these channels using only 64 state encoders.
Approximately universal codes over slow fading channels
 IEEE Trans. Inform. Theory
, 2006
"... Performance of reliable communication over a coherent slow fading channel at high SNR is succinctly captured as a fundamental tradeoff between diversity and multiplexing gains. We study the problem of designing codes that optimally tradeoff the diversity and multiplexing gains. Our main contribution ..."
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Cited by 107 (1 self)
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Performance of reliable communication over a coherent slow fading channel at high SNR is succinctly captured as a fundamental tradeoff between diversity and multiplexing gains. We study the problem of designing codes that optimally tradeoff the diversity and multiplexing gains. Our main contribution is a precise characterization of codes that are universally tradeoffoptimal, i.e., they optimally tradeoff the diversity and multiplexing gains for every statistical characterization of the fading channel. We denote this characterization as one of approximate universality where the approximation is in the connection between error probability and outage capacity with diversity and multiplexing gains, respectively. The characterization of approximate universality is then used to construct new coding schemes as well as to show optimality of several schemes proposed in the spacetime coding literature. 1
Nonbinary LDPC coding for multicarrier underwater acoustic communication
 IEEE J. Sel. Areas Commun
"... Abstract — In this paper, we propose to use nonbinary low density parity check (LDPC) codes to address two main issues in underwater acoustic OFDM communication: i) plain OFDM has poor performance in the presence of channel fading, and ii) OFDM transmission has a high peaktoaveragepower ratio (PA ..."
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Cited by 48 (38 self)
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Abstract — In this paper, we propose to use nonbinary low density parity check (LDPC) codes to address two main issues in underwater acoustic OFDM communication: i) plain OFDM has poor performance in the presence of channel fading, and ii) OFDM transmission has a high peaktoaveragepower ratio (PAPR). We propose new methods to construct nonbinary irregular LDPC codes that achieve excellent performance, match well with the underlying modulation, and can be encoded in linear time and in parallel. Simulation and experimental results confirm the excellent performance of the proposed nonbinary LDPC codes. Based on the property that the generator matrix of LDPC codes has high density, we further show how to reduce the PAPR considerably with minimal overhead. I.
Great expectations: The value of spatial diversity in wireless networks
 PROCEEDINGS OF THE IEEE
, 2004
"... In this paper, the effect of spatial diversity on the throughput and reliability of wireless networks is examined. Spatial diversity is realized through multiple independently fading transmit/receive antenna paths in singleuser communication and through independently fading links in multiuser commu ..."
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Cited by 45 (8 self)
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In this paper, the effect of spatial diversity on the throughput and reliability of wireless networks is examined. Spatial diversity is realized through multiple independently fading transmit/receive antenna paths in singleuser communication and through independently fading links in multiuser communication. Adopting spatial diversity as a central theme, we start by studying its informationtheoretic foundations, then we illustrate its benefits across the physical (signal transmission/coding and receiver signal processing) and networking (resource allocation, routing, and applications) layers. Throughout the paper, we discuss engineering intuition and tradeoffs, emphasizing the strong interactions between the various network functionalities.
Fading–Resistant Modulation Using Several Transmitter Antennas
 IEEE Trans. on Commun
, 1997
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Design, analysis, and performance evaluation for BICMID with square QAM constellations in Rayleigh fading channels
 IEEE J. Select. Areas Commun
, 2001
"... Abstract—We consider bitinterleaved coded modulation with iterative decoding (BICMID) for bandwidthefficient transmission over Rayleigh fading channels. We propose the design criteria that utilize a large Hamming distance inherited in a lowrate code and a new labeling technique designed specifi ..."
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Cited by 34 (2 self)
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Abstract—We consider bitinterleaved coded modulation with iterative decoding (BICMID) for bandwidthefficient transmission over Rayleigh fading channels. We propose the design criteria that utilize a large Hamming distance inherited in a lowrate code and a new labeling technique designed specifically for fading channels. This results in large coding gain over noniterative coded modulation and performance close to that of “turbo ” coded modulation with less complexity. We also show that BICMID designed for fading channel usually has a very good performance over the additive white Gaussian noise (AWGN) channel while the converse is difficult to achieve. When combined with signal space diversity, diversity order can be improved to twice the diversity order of conventional BICMID; therefore, the code complexity can further be reduced while maintaining the same level of performance. Specifically, with the bandwidth efficiency of 2 bits/s/Hz over Rayleigh fading channels, a bit error rate (BER) of 10 6 can be achieved with 16QAM, a fourstate rate 1/2 code at 0 of about seven dB. We also derive performance bounds for BICMID with and without signal space diversity over Rayleigh fading channels, which can be easily extended for other types of fading channels. Index Terms—Bandwidthefficient coded modulation, BICM, fading channels, iterative decoding, turbo codes. I.
Serial and hybrid concatenated codes with applications
 Proc. Intl. Symp. Turbo Codes and Appls
, 1997
"... Abstract — Analytical bounds on the performance of concatenated codes on a tree structure are obtained. Analytical results are applied to examples of parallel concatenation of two codes (turbo codes), serial concatenation of two codes, hybrid concatenation of three codes, and self concatenated codes ..."
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Cited by 28 (1 self)
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Abstract — Analytical bounds on the performance of concatenated codes on a tree structure are obtained. Analytical results are applied to examples of parallel concatenation of two codes (turbo codes), serial concatenation of two codes, hybrid concatenation of three codes, and self concatenated codes, over AWGN and fading channels. Based on the analysis, design criteria for the selection of component codes are presented. Asymptotic results for large interleavers are extended to MPSK modulations over AWGN and Rayleigh fading channels. Simulation results are only given for examples of coded modulation and fading channels. 1.
A New View of Performance Analysis Techniques in Correlated Rayleigh Fading
, 1999
"... This paper provides a new formulation for the pairwise error probability for any coherently demodulated system in Rayleigh fading. The novelty of the result is that the resulting error rate expression is a polynomial function of the eigenvalues of a "signal" matrix. This view also enable ..."
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Cited by 28 (13 self)
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This paper provides a new formulation for the pairwise error probability for any coherently demodulated system in Rayleigh fading. The novelty of the result is that the resulting error rate expression is a polynomial function of the eigenvalues of a "signal" matrix. This view also enables a simple new asymptotically tight bound on the pairwise error probability. Examples of single and multiple transmit antenna systems are considered. Keywords Diversity, Rayleigh Fading, Performance Analysis, Spacetime Coding I. Introduction Performance analysis of digital communications systems in fading channels has been an area of longtime interest. Results were first obtained in [1]. An elegant unified technique was presented in [2], [3] for signals experiencing complex Gaussian fading and advanced textbooks have significant sections discussing related results [4]. Improvements and generalizations continued to be derived through the current time (e.g., [5]). An extensive bibliography of imp...
Adaptive PSAM Accounting for Channel Estimation and Prediction Errors
, 2004
"... Adaptive modulation requires channel state information (CSI), which can be acquired at the receiver by inserting pilot symbols in the transmitted signal. In this paper, we first analyze the effect linear minimum mean square error (MMSE) channel estimation and prediction errors have on bit error rate ..."
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Cited by 22 (1 self)
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Adaptive modulation requires channel state information (CSI), which can be acquired at the receiver by inserting pilot symbols in the transmitted signal. In this paper, we first analyze the effect linear minimum mean square error (MMSE) channel estimation and prediction errors have on bit error rate (BER). Based on this analysis, we develop adaptive pilot symbol assisted modulation (PSAM) schemes that account for both channel estimation and prediction errors to meet a target BER. While pilot symbols facilitate channel acquisition, they consume part of transmitted power and bandwidth, which in turn reduces spectral efficiency. With imperfect (and thus partial) CSI available at the transmitter and receiver, two questions arise naturally: how often should pilot symbols be transmitted? and how much power should be allocated to pilot symbols? We address these two questions by optimizing pilot parameters to maximize spectral efficiency.
Constellation labeling for linear encoders
 IEEE TRANS. INFORM. THEORY
, 2001
"... This paper investigates optimal constellation labeling in the context of the edge profile. A constellation’s edge profile lists the minimumdistance edge for each binary symbol error. The paper introduces the symmetricultracomposite (SU) labeling structure and shows that this structure provides un ..."
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Cited by 19 (6 self)
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This paper investigates optimal constellation labeling in the context of the edge profile. A constellation’s edge profile lists the minimumdistance edge for each binary symbol error. The paper introduces the symmetricultracomposite (SU) labeling structure and shows that this structure provides undominated edge profiles for 2PSK, 2PAM, and 22point square QAM. The SU structure is a generalization of the commonly used reflected binary Gray code. With the proper choice of basis vectors, SU labeling can support either setpartition or Graycode labeling of 2PSK, 2PAM, and 22point square QAM. Notably, there are Graycode and setpartition labelings that do not have the SU structure. These labelings yield inferior edge profiles. The SU structure does not apply to cross constellations. However, for any standard cross constellation with 32 or more points, a quasiSU labeling structure can approximate the SU structure. With the correct choice of basis, quasiSU labelings produce quasiGray labelings. However, the quasiSU structure cannot support setpartition labeling. In fact, the quasiSU structure provides a better edge profile than standard setpartition labeling. Thus, for cross constellations there is a choice between edge profile optimality and the group structure provided by setpartitioning. Here, the correct choice depends on whether the encoder trellis has parallel branches.