Test Whats new message.
Scheduled Maintenance on Monday 1/13/2025
Single article sales and account management will be unavailable from 5:00 AM - 7:00 PM ET (09:00 - 23:00 UTC). We apologize for the inconvenience.
Showing 1-25 of 44 results
- Sort
Get notified when new research is published matching your search criteria.
Sort By
Results
A Message-Passing Algorithm for Counting Short Cycles in Nonbinary LDPC Codes
2018 IEEE International Symposium on Information Theory (ISIT)
Year: 2018 | Conference Paper |
Cited by: Papers (4)
Trapping sets with short cycles are known to give a detrimental effect on the error floor performance of a low-density parity-check (LDPC) code. Unlike in binary LDPC codes., short cycles in a nonbinary low-density parity-check (NB-LDPC) code may be even more harmful to its performance if they do not satisfy the so-called full rank condition (FRC). This is because they may induce low-weight codewo...Show More
Design of Nonbinary LDPC Codes Based on Message-Passing Algorithms
Short cycles in a nonbinary low-density parity-check (NB-LDPC) code may be even more harmful to its performance if they do not satisfy the so-called full rank condition (FRC). This is because they may induce low-weight codewords or absorbing sets in that case. Thus, it is important to count the number of short cycles not satisfying the FRC as well as the number of short cycles for analyzing the pe...Show More
Low-Complexity Decoding of Block Turbo Codes Based on the Chase Algorithm
IEEE Communications Letters
Cited by: Papers (10)
Block turbo codes (BTCs) are constructed by serially concatenating linear block codes and iteratively decoded by letting each component code be decoded in two stages. The Chase algorithm is employed in the first stage to make a list of candidate codewords by generating a fixed number of test sequences (TSs) and algebraically decoding them, regardless of the signal-to-noise ratio or the iteration n...Show More
Feasibility of Mobile Cellular Communications at Millimeter Wave Frequency
Yungsoo Kim;Hyun-Yong Lee;Philyeong Hwang;Ranjeet Kumar Patro;Jaekon Lee;Wonil Roh;Kyungwhoon Cheun
High data rate at high mobile speed will still be an essential requirement for the future 5G mobile cellular system. High frequency bands above 6 GHz are particularly promising for the 5G system because of large signal bandwidths such high frequencies can offer. By using high gain beamforming antennas, the problem of high propagation loss at high frequencies can be overcome. However, the use of be...Show More
Feasibility of Mobile Cellular Communications at Millimeter Wave Frequency
Yungsoo Kim;Hyun-Yong Lee;Jongho Oh;Jaekon Lee;Wonil Roh;Kyungwhoon Cheun
2015 IEEE Global Communications Conference (GLOBECOM)
Year: 2015 | Conference Paper |
Cited by: Papers (4)
High data rate at high mobile speed will still be an essential requirement for the future 5G mobile cellular system. High frequency bands above 6 GHz are particularly promising for the 5G system because of large signal bandwidths such high frequencies can offer. And it was shown that by using high gain beamforming antennas, the problem of high propagation loss at high frequencies could be compensa...Show More
Holistic design considerations for environmentally adaptive 60 GHz beamforming technology
Ohyun Jo;Wonbin Hong;Sung Tae Choi;Sanghyun Chang;Changyeul Kweon;Jisung Oh;Kyungwhoon Cheun
Proliferation of all forms of smart devices has driven the demand for high-data-rate Wi-Fi in recent years. Utilizing wide bandwidth in high frequency is the most efficient way of guaranteeing the explosive data demands. In spite of the notable advancements of RF technologies at millimeter wave, the relatively high propagation loss remains problematic. The authors present efficient beamforming tec...Show More
A modulation technique for active interference design under downlink cellular OFDMA networks
Sungnam Hong;Min Sagong;Chiwoo Lim;Kyungwhoon Cheun;Sunghye Cho;Young Min Choi
2014 IEEE Wireless Communications and Networking Conference (WCNC)
Year: 2014 | Conference Paper |
In cellular systems, the interference has been the most critical issue that practically limits the performance of overall networks. Furthermore, the distribution of the inter-cell interference (ICI) in conventional cellular networks employing orthogonal frequency-division multiple-access (OFDMA) with quadrature amplitude modulation (QAM) tends to approach a Gaussian distribution, which is known to...Show More
People in real estate joke that there are only three things that matter in the business of buying and selling property: location, location, location. The same could be said for radio spectrum. The frequencies used for cellular communications have acquired the status of waterfront lots-highly coveted and woefully scarce. And like beach-home buyers in a bidding war, mobile operators must constantly ...Show More
Frequency and Quadrature-Amplitude Modulation for Downlink Cellular OFDMA Networks
Sungnam Hong;Min Sagong;Chiwoo Lim;Sunghye Cho;Kyungwhoon Cheun;Kyeongcheol Yang
The distribution of the intercell interference (ICI) in conventional cellular networks employing orthogonal frequency-division multiple-access (OFDMA) with quadrature-amplitude modulation (QAM) tends to approach a Gaussian distribution when all available subcarriers in each cell are fully loaded. Recently, it has been also shown that the worst-case distribution of the ICI as additive noise in wire...Show More
Millimeter-wave beamforming as an enabling technology for 5G cellular communications: theoretical feasibility and prototype results
Wonil Roh;Ji-Yun Seol;Jeongho Park;Byunghwan Lee;Jaekon Lee;Yungsoo Kim;Jaeweon Cho;Kyungwhoon Cheun;Farshid Aryanfar
The ever growing traffic explosion in mobile communications has recently drawn increased attention to the large amount of underutilized spectrum in the millimeter-wave frequency bands as a potentially viable solution for achieving tens to hundreds of times more capacity compared to current 4G cellular networks. Historically, mmWave bands were ruled out for cellular usage mainly due to concerns reg...Show More
FQAM : A modulation scheme for beyond 4G cellular wireless communication systems
Sungnam Hong;Min Sagong;Chiwoo Lim;Kyungwhoon Cheun;Sunghye Cho
2013 IEEE Globecom Workshops (GC Wkshps)
Year: 2013 | Conference Paper |
We analyze the performance of bit interleaved coded modulation (BICM) and coded modulation (CM) systems with frequency and quadrature amplitude modulation (FQAM), which is a combination of frequency shift keying (FSK) and quadrature amplitude modulation (QAM). Numerical results show that for modest code rates in low signal-to-noise ratio regions, the normalized throughputs of FQAM based CM systems...Show More
Performance of M-ary turbo coded synchronous FHSS multiple access networks with noncoherent MFSK under Rayleigh fading channels
The performance of M-ary turbo coded synchronous, fast frequency-hopping spread spectrum multiple-access (FHSS-MA) networks with M-ary frequency shift keying (MFSK) and noncoherent detection is analyzed under Rayleigh fading. Results indicate that M-ary turbo codes dramatically enhance the performance of FHSS-MA networks using MFSK compared to binary turbo codes.Show More
Noncoherent unitary space-time modulated DSSS systems in multipath channels
In this paper, in order to effectively apply unitary space-time modulation to the direct-sequence spread-spectrum multiple-access (DSSS-MA) networks, we propose a low-rate, noncoherent, unitary, and space-time modulated DSSS system supporting any number of transmit antennas based on Walsh matrices. The proposed scheme simultaneously performs bandwidth spreading and space-time coding and outperform...Show More
An efficient sliding window algorithm using adaptive-length guard window for turbo decoders
An efficient sliding window algorithm employing an adaptive-length guard window for turbo decoders is proposed. The proposed algorithm results in significant complexity reductions, especially for small sliding window lengths where the additional computational complexity required for the guard window is critical.Show More
A Systematic Granulized Piecewise Linear Approximation to the Jacobian Logarithm
A systematic, granulized piecewise linear approximation to the Jacobian logarithm is developed. This approximation reverts to the Jacobian approximation and the exact Jacobian logarithm at the far extremes. The utility of the derived approximation is demonstrated by applying it to the decoding of Turbo coded, MIMO/BICM-ID systems.Show More
A Statistical Inter-Cell Interference Model for Uplink Cellular OFDMA Networks Under Log-Normal Shadowing and Rayleigh Fading
IEEE Communications Letters
Cited by: Papers (6)
The performance of uplink cellular OFDMA networks transmitting multiple QAM symbols per hop is evaluated under log-normal shadowing and Rayleigh fading without resorting to a Gaussian approximation of the inter-cell interference. The derived interference statistic is observed to deviate significantly from the Gaussian distribution which may be exploited to dramatically enhance the network performa...Show More
Design of Irregular Weighted Nonbinary Repeat-Accumulate Codes over GF(q) with q-ary Orthogonal Modulation Using a Gaussian Approximation
Using a Gaussian approximation to the distribution of the message vectors under density evolution, we design irregular weighted nonbinary repeat-accumulate codes over GF(q) with q-ary orthogonal modulation. The resulting codes achieve a frame error rate of 10-1 within 0.56 to 0.91 dB of channel capacity under the AWGN channel.Show More
Performance of Weighted Nonbinary Repeat-Accumulate Codes over GF(q) with q-ary Orthogonal Modulation
An approximate upper bound is derived to the maximum likelihood decoding threshold of weighted nonbinary repeat-accumulate (WNRA) codes over GF(q) with q-ary orthogonal modulation and coherent detection over the additive white Gaussian noise channel. As with binary RA codes, WNRA codes show the potential for achieving the channel capacity with decreasing code rate for large enough q.Show More
Design of Turbo Codes over GF(q) with q-ary Orthogonal Modulation
A very simple design rule for parallel concatenated Turbo codes over GF(q) with q-ary orthogonal modulation is proposed. Unlike previously proposed exhaustive search methods, the proposed design rule allows straightforward and systematic code designs for any value of q ≥ 2 and any constraint length greater than 2.Show More
Performance of Soft Decision Decoded Synchronous FHSS Multiple Access Networks Using MFSK Modulation under Rayleigh Fading
In this paper, we analyze the performance of soft decision decoded, synchronous, fast frequency-hopping spread-spectrum multiple-access networks using M-ary frequency shift keying in Rayleigh fading channels under the assumption that the number of frequency hopping slots is sufficiently large. The joint probability density function (pdf) of the absolute values of the correlator outputs is derived ...Show More
Iterative Receivers Based on Subblock Processing for Phase Noise Compensation in OFDM Systems
An iterative algorithm employing decision feedback provided by either an equalizer or a channel decoder is proposed in order to compensate for the phase noise resulting from imperfect oscillators in orthogonal frequency-division multiplexing (OFDM) systems. In the proposed algorithm, the received OFDM symbol is partitioned into subblocks in the time domain and the estimate of the time-average of t...Show More
A Statistical Inter-Cell Interference Model for Downlink Cellular OFDMA Networks Under Log-Normal Shadowing with Ricean Fading
IEEE Communications Letters
Cited by: Papers (11)
In this letter, an approximation to the performance of downlink cellular orthogonal frequency division multiple access networks under log-normal shadowing and Ricean fading is evaluated. The interference statistic is shown to significantly deviate from the Gaussian distribution as shown in previous results under Rayleigh fading.Show More
Unitary space-time constellations based on quasi-orthogonal sequences
In this paper, we propose a novel class of unitary space-time constellations based on quaternary quasi-orthogonal sequences (QOSs), minimizing the maximum correlation between the signal matrices. The proposed design, owing to the underlying algebraic structure of the QOSs, allows for an efficient decoder structure while offering performance virtually identical to the unitary space-time constellati...Show More
Improving the performance of SM-MIMO/BICM-ID systems with LLR distribution matching
In this paper, a distribution matching technique is proposed to process the extrinsic information produced by practical multiple-antenna detectors with iteratively demodulated, bit-interleaved coded modulation (BICM-ID). It is shown that significant gains may be achieved by appropriately processing the extrinsic information generated by practical multiple-antenna detectors before feeding it to the...Show More
A statistical inter-cell interference model for downlink cellular OFDMA networks under log-normal shadowing and multipath Rayleigh fading
The probability density function (PDF) of the intercell interference for downlink cellular orthogonal frequency division multiple access networks under log-normal shadowing and multipath Rayleigh fading is derived. The derived PDF is observed to highly deviate from the Gaussian distribution, especially at moderate to small network loads. Based on the derived inter-cell interference statistics, the...Show More
IEEE Account
Purchase Details
Profile Information
Need Help?
- US & Canada: +1 800 678 4333
- Worldwide: +1 732 981 0060
- Contact & Support
- About IEEE Xplore
- Contact Us
- Help
- Accessibility
- Terms of Use
- Nondiscrimination Policy
- Sitemap
- Privacy & Opting Out of Cookies
A not-for-profit organization, IEEE is the world's largest technical professional organization dedicated to advancing technology for the benefit of humanity.
© Copyright 2025 IEEE - All rights reserved. Use of this web site signifies your agreement to the terms and conditions.