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Iterative multi-channel FH-MFSK reception in mobile shallow underwater acoustic channels

IET COMMUNICATIONS 2020年第5期14卷 838-845页

作者： Sun, Dajun Hong, Xiaoping Cui, Hongyu Liu, Lu Harbin Engn Univ Acoust Sci & Techol Lab Harbin 150001 Peoples R China Harbin Engn Univ Coll Underwater Acoust Engn Harbin 150001 Peoples R China

Frequency-hopped M-ary frequency-shift-keyed (FH-MFSK) has the ability to handle with long multipath, large Doppler spreads, high ambient noise and rapid phase fluctuation, and is proved to be a robust modulation scheme in mobile shallow underwater acoustic channels. Aiming at this topic, a convolutionally encoded FH-MFSK modulation scheme with a novel iterative multi-channel reception is proposed. To obtain the novel reception suitable for non-coherent M-ary frequency-shift-keyed, the ideas of iterative multi-channel demodulation and decoding are combined and extended. A modified multi-channel soft-input-soft-output demodulator based on maximum-a-posterior criterion is derived, and substantial gains of several decibels in power efficiency are achieved. Extra gain can be obtained by utilising time diversity with long multipath delay. Simulation shows that a non-coherent receiver equipped with five arrays obtains around 5.5 dB gain over the single non-iterative receiver. A shallow water field testing at Songhua Lake with 300 m distance confirms that the proposed receiver verifies its robustness and usability.

关键词： multipath channels underwater acoustic communication modulation coding wireless channels frequency shift keying radio receivers channel coding frequency hop communication convolutional codes iterative decoding mobile computing maximum likelihood estimation iterative multichannel FH-MFSK reception mobile shallow underwater acoustic channels frequency-hopped M-ary frequency-shift-keyed high ambient noise rapid phase fluctuation robust modulation scheme convolutionally encoded FH-MFSK modulation scheme novel iterative multichannel reception decoding multichannel soft-input-soft-output demodulator long multipath delay noniterative receiver noise figure 5 5 dB size 300 0 m

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Iterative receiver for the triple differential PSK modulation in the time-varying underwater acoustic communications

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IET COMMUNICATIONS 2020年第16期14卷 2813-2819页

作者： Cui, Hongyu Liu, Changxin Si, Boyu Wu, Jie Sun, Dajun Harbin Engn Univ Acoust Sci & Techol Lab Harbin 150001 Peoples R China Harbin Engn Univ Coll Underwater Acoust Engn Harbin 150001 Peoples R China Shanghai Univ Med & Hlth Sci Coll Med Instrument Shanghai 201318 Peoples R China

Due to the time-varying property of the underwater acoustic (UWA) channel, the significant Doppler spread will severely degrade the performance of direct-sequence spread-spectrum (DSSS) communications. The relative velocity variation between the transmitter and the receiver will cause both the phase rotation and the magnitude loss of correlation peak, during the long transmission of the DSSS packet. To solve this problem, the authors propose a novel transceiver design for the UWA DSSS communications. At the transmitter, the triple differential phase shift keying (D3PSK) modulation is adopted to overcome the phase rotation, whereas the phase noise will be amplified resulting in the signal-to-noise ratio (SNR) loss. At the receiver, the improved bit-interleaved coded modulation with iterative decoding algorithm for D3PSK is used to recover the SNR loss, in which the D3PSK demodulator is treated as the convolutional decoder, and the linear prediction is adopted to track the channel variation. Furthermore, an adaptive selection of local reference signal is also applied to recover the correlation loss. Theoretical simulation shows that the proposed transceiver can effectively mitigate the performance loss caused by the motion acceleration, and the performance gain is significant over the conventional.

关键词： iterative decoding differential phase shift keying transceivers underwater acoustic communication spread spectrum communication interleaved codes modulation coding signal detection demodulation wireless channels time-varying channels phase noise convolutional codes channel coding iterative receiver triple differential PSK modulation time-varying underwater acoustic communications time-varying property underwater acoustic channel Doppler spread direct-sequence spread-spectrum communications relative velocity variation transmitter phase rotation magnitude loss DSSS packet novel transceiver design UWA DSSS communications phase noise signal-to-noise ratio loss iterative decoding algorithm SNR loss channel variation local reference signal performance gain UWA channel receiver triple differential phase shift keying modulation D3PSK modulation improved bit-interleaved coded modulation D3PSK demodulator convolutional decoder linear prediction adaptive selection correlation loss recovery performance loss mitigation motion acceleration

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4-ary 14/16 modulation code for reducing two-dimensional inter-symbol interference

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IET COMMUNICATIONS 2020年第8期14卷 1335-1339页

作者： Kim, Juri Jeong, Seongkwon Lee, Jaejin Soongsil Univ Sch Elect Engn 369Sangdo Ro Seoul South Korea Soongsil Univ Dept ICMC Convergence Technol 369Sangdo Ro Seoul South Korea

Holographic data storage (HDS) can access data in a short amount of time and can also quickly transmit data because HDS records and reads data in units of pages. Thus HDS is regarded as a promising candidate for future optical recording storage systems. Conventional storage systems such as CD, DVD, and HDD have one-dimensional (1D) inter-symbol interference (ISI). However, HDS has a 2D ISI that degrades performance. In this study, to avoid and overcome the 2D-ISI problem, the authors propose a 14/16 modulation code for 4-ary HDS systems which represents 2 bits on each pixel. The proposed 14/16 modulation code allows a bit of unwanted ISI cases in order to raise the code rate, but it has a higher code rate but similar performance compared to a 3/4 modulation code that has no unwanted ISI cases.

关键词： intersymbol interference holographic storage modulation coding two-dimensional intersymbol interference holographic data storage HDS records 2D-ISI problem 4-ary HDS systems code rate optical recording storage systems 4-ary 14 16 modulation code word length 2 0 bit

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Prefix-Free Code Distribution Matching for Probabilistic Constellation Shaping

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IEEE TRANSACTIONS ON COMMUNICATIONS 2020年第2期68卷 670-682页

作者： Cho, Junho Nokia Bell Labs Holmdel NJ 07733 USA

In this paper, we construct variable-length prefix-free codes that are optimal (or near-optimal) in the sense that no (or few) other codes of the same cardinality can achieve a smaller expected energy per code symbol for the same resolution rate. Under stringent constraints of 4096 codewords or below per codebook, the constructed codes yield an energy per code symbol within a few tenths of a dB of the unconstrained theoretic lower bound, across a wide range of resolution rates with fine granularity. We also propose a framing method that allows variable-length codes to be transmitted using a fixed-length frame. The penalty caused by framing is studied using simulations and analysis, showing that the energy per code symbol is kept within 0.3 dB of the unconstrained theoretic limit for some tested codes with a large frame length. When the proposed method is used to implement probabilistic constellation shaping for communications in the additive white Gaussian noise channel, simulations show that between 0.21 dB and 0.98 dB of shaping gains are achieved relative to uniform 4-, 8-, 16-, and 32-ary quadrature amplitude modulation.

关键词： Huffman coding modulation coding quadrature amplitude modulation constellation shaping

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Bit-level implementation for polynomial cancellation coded DFT-s-OFDM transmitters

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ELECTRONICS LETTERS 2020年第5期56卷 250-+页

作者： Cho, L. Hsu, C. -Y. Tatung Univ Grad Inst Commun Engn Taipei 10452 Taiwan

Polynomial cancellation coded discrete Fourier transform-spread orthogonal frequency division multiplexing (PCC-DFT-s-OFDM) is famous for the flexibility of DFT-s-OFDM on the trade-off between peak-to-average power ratio performance and spectral efficiency. Deploying it on numerous user equipments (UEs) as enhanced uplink signalling becomes a practical issue. In this Letter, a bit-level implementation of PCC mapping is proposed, so that the compatibility of implementation of corresponding circuits on UE transmitters would make the deployment more easily. By taking Long Term Evolution and New Radio standards as examples, the equivalency of bit/symbol-level implementations is validated in terms of bit error rate performance.

关键词： error statistics discrete Fourier transforms OFDM modulation radio transmitters modulation coding Long Term Evolution bit-level implementation polynomial cancellation DFT-s-OFDM transmitters discrete Fourier transform-spread peak-to-average power ratio performance spectral efficiency numerous user equipments enhanced uplink signalling PCC mapping UE transmitters bit error rate performance

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Design of 4/6 ITI-mitigating error correction modulation code for ultra-high-density bit-patterned media recording systems

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ELECTRONICS LETTERS 2020年第18期56卷 931-933页

作者： Nguyen, C. D. Phenikaa Univ Fac Elect & Elect Engn Hanoi 12116 Vietnam Phenikaa Res & Technol Inst PRATI A&A Green Phoenix Grp JSC 167 Hoang Ngan Hanoi 11313 Vietnam

A design of 4/6 intertrack-interference (ITI)-mitigating error correction modulation code for bit-patterned media recording systems is proposed in this Letter. Generally, coding schemes in data storage devices are usually accomplished using a combination of error-correction coding and modulation coding. However, an interesting approach is that the modulation code itself has the capability of correcting errors. Such a modulation code design will reduce the total size and complexity of the data storage devices. In this Letter, the authors design a new 4/6 modulation code, where the code not only mitigates the effect of ITI but also maintains minimum Hamming distance of 2 to build up a trellis structure providing error correction capability of the proposed code. Simulation results show that the proposed design outperforms prior arts. For instance, the performance of the proposed design is better than that of a conventional 4/6 modulation code about 8 dB at a bit error rate of 10(-7)under 20% read-head offtrack for the area density of 4 Tb/in(2).

关键词： error statistics intersymbol interference error correction codes Viterbi decoding magnetic recording error correction channel coding modulation coding modulation coding correcting errors modulation code design data storage devices authors design error correction capability bit error rate ultra-high-density bit-patterned media bit-patterned media recording systems error-correction coding noise figure 8 0 dB

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modulation coding for flash memories

Modulation coding for flash memories

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International Conference on Computing, Networking and Communications (ICNC)

作者： Yongjune Kim B. V. K. Vijaya Kumar Kyoung Lae Cho Hongrak Son Jaehong Kim Jun Jin Kong Jaejin Lee Data Storage Systems Center Carnegie Mellon University Pittsburgh USA Flash Development Team Samsung Electronics Company Limited Hwasung South Korea School of Electronic Engineering Soongsil University Seoul South Korea

The aggressive scaling down of flash memories has threatened data reliability since the scaling down of cell sizes gives rise to more serious degradation mechanisms such as cell-to-cell interference and lateral charge spreading. The effect of these mechanisms has pattern dependency and some data patterns are more vulnerable than other ones. In this paper, we will categorize data patterns taking into account degradation mechanisms and pattern dependency. In addition, we propose several modulation coding schemes to improve the data reliability by transforming original vulnerable data patterns into more robust ones.

关键词： Interference Computer architecture Microprocessors Flash memories Threshold voltage modulation coding Encoding

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Noncoherent optical CDMA system of 2-D subtracted square codes using two code keying by eliminating the multiple use interferences

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OPTICAL FIBER TECHNOLOGY 2021年 66卷

作者： Yeh, Bih-Chyun Chang Gung Univ Sch Elect & Comp Engn Dept Elect Engn Coll Engn Taoyuan Taiwan

We propose the new two-dimensional subtracted square (SS) codes to achieve the new family in the spectral amplitude coding (SAC) optical code division multiple access (OCDMA) networks. The proposed codes give the multiplication between the 1-D subtracted square codes and 1-D subtracted square codes to become the code sequences of the 2-D SS codes. The proposed structure using the 2-D SS codes constructs the proposed transmitter and proposed receiver to build the code sequences of the 2-D SS codes and recovered bits using the modified cross-correlation, respectively. The proposed transmitter activates the 2-D SS codes to convert the code sequences of the 2-D SS codes. The proposed receiver gets the code sequences of the 2-D SS codes to decode the recovered bits, which cancel the interferences in the powers called the multiple user interferences (MUI). The proposed receiver transfers the cross-correlation to the modified cross-correlation, which eliminates the MUI. The modified cross-correlation takes the photodiodes to suppress the phase-induced intensity noise (PIIN), simultaneously. In numerical results, the bit error rate (BER) gets the number of the simultaneous users in the proposed system using the 2-D SS codes to accomplish the all users with 84 users. And the BER takes the data transmission rate in the proposed system using the 2-D SS codes to attain the 7.1 Gbps.

关键词： modulation coding Optical modulation Optical code division multiplexing Multiple user interference Phase intensity Phase induced intensity noise

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Labeling-Based Recipient Identification for BICM-ID in 64-QAM case 16

Labeling-Based Recipient Identification for BICM-ID in 64-QA...

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16th IEEE International Wireless Communications and Mobile Computing Conference (IEEE IWCMC)

作者： Krasicki, Maciej Poznan Univ Tech Fac Comp & Telecommun Inst Radiocommun Polanka 3 PL-61623 Poznan Poland

ISBN: (纸本)9781728131290

In this paper a novel method for physical-layer addressing in wireless networks, called LAbeling-Based Recipient IDentification (LABRID), is studied. It is thought as a small and low-cost amendment to Bit-Interleaved Coded modulation with Iterative Decoding (BICM-ID) - one of the primary transmission techniques for future wireless communications. LABRID consists in using different signal labeling maps for different recipients. Thanks to this simple yet effective method, the decision about frame destination can be made at the receiver side without any interaction with Medium Access Control (MAC) logic. Instead, foreign frames can be rejected in the physical layer, once no convergence of iterative process is detected. LABRID has been never considered for 64-QAM BICM-ID - this paper fills this gap. A complete system model is developed and the ability of LABRID to identify desired frames is investigated.

关键词： iterative decoding modulation coding TCP/IP turbo codes

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Cognitive cross network design with physical-layer coding and spatial modulation

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ELECTRONICS LETTERS 2017年第6期53卷 432-434页

作者： Ustunbas, S. Basar, E. Aygolu, U. Istanbul Tech Univ Fac Elect & Elect Engn TR-34469 Istanbul Turkey

A cognitive cross network where both primary and secondary users' receivers are closer to the transmitter of the other user;however, the distances to their own transmitters are too large that a relay is required for a reliable communication, is considered. To this end, the secondary user shares its relay with the primary user (PU) by means of physical-layer network coding in exchange for access to PU's licensed band. It is assumed that both transmitters and the relay adopt the emerging spatial modulation concept to improve the error performance. Bit error probability of the proposed scheme is analytically derived and supported via computer simulation results.

关键词： cognitive radio radio transmitters radio receivers telecommunication network reliability relay networks (telecommunication) network coding error statistics modulation coding cognitive cross network design primary user receiver secondary user receiver communication reliability physical- layer network coding PU licensed band spatial modulation concept bit error probability error performance improvement computer simulation

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