Underwater communication link with iterative equalization

Oberg, T.; Nilsson, B.; Olofsson, Niten; Nordenvaad, Magnus Lundberg; Sangfelt, Erland

doi:10.1109/oceans.2006.307059

Cited by 26 publications

(12 citation statements)

References 6 publications

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“…The typical frequencies associated with this type of communication are 10 Hz to 1 MHz. However, it is well known that this technology suffers from a very small bandwidth availability [119], very low celerity, lack of stealth, and large latencies due to the low propagation speed [120]. As such, data rates using underwater acoustic communication are limited to a few hundreds or thousands of kbit/s.…”

Section: Underwater Communicationmentioning

confidence: 99%

Communicating Using Spatial Mode Multiplexing: Potentials, Challenges, and Perspectives

Trichili

Park

Zghal

et al. 2019

IEEE Commun. Surv. Tutorials

184

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Time, polarization, and wavelength multiplexing schemes have been used to satisfy the growing need of transmission capacity. Using space as a new dimension for communication systems has been recently suggested as a versatile technique to address future bandwidth issues. We review the potentials of harnessing the space as an additional degree of freedom for communication applications including free space optics, optical fiber installation, underwater wireless optical links, on-chip interconnects, data center indoor connections, radio frequency and acoustic communications. We focus on the orbital angular momentum (OAM) modes and equally identify the challenges related to each of the applications of spatial modes and the particular OAM modes in communication. We further discuss the perspectives of this emerging technology. Finally, we provide the open research directions and we discuss the practical deployment of OAM communication links for different applications. ). 4 in the future. We also summarize the open problems and the future research directions. A discussion of the practicability and cost of multi-OAM communication is also included. II. OAM POTENTIALS A. Free Space Optical CommunicationFSO is a license free wireless communication configuration that has recently received much interest for a variety of applications. FSO is an attractive solution for last mile connectivity problems, particularly for communication networks, when the installation of fiber optics is costly or not possible [66]. FSO can be also used to establish inter-building secure communication, and can be deployed as a backup to optical fibers. Wireless optical communication can guarantee a line-of-sight (LoS) high bit rate wireless transmission over long distances, up to several kilometers. Furthermore, FSO communication is considered as a promising technique to scale down bandwidth challenges in future 5G networks [67].Multiple wavelength FSO provides better transmission, as demonstrated in [68], [69]. Data can be mapped on advanced modulation formats to achieve high bit rates and high spectral efficiency levels [70]- [72]. Another option is multiple-input and multiple-output (MIMO) FSO communication in which multiple lasers are positioned to transmit Gaussian beams to multiple receiving apertures [73]. Over the last few years, it has been proven that it is possible to transmit information over spatially structured light beams [21], [74], [75] including OAM beams and plane waves. Our focus is on the OAM modes of light.The first PoC communication experiment incorporating OAMs in free space was carried out in 2004 by Gibson and co-workers [21]. Over a 15-meter long link, 8 -spaced values were chosen along the Gaussian beam as an alphabet for the communication. OAM beams were generated and detected using two light modulators. Since then, much progress has been made and free space transmission capacity of over 1 Tbit/s is, today, possible [76]- [78]. By performing three dimensional multiplexing, Huang and co-workers were able to attain a 100 Tbi...

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Section: Underwater Communicationmentioning

confidence: 99%

Communicating Using Spatial Mode Multiplexing: Potentials, Challenges, and Perspectives

Trichili

Park

Zghal

et al. 2019

IEEE Commun. Surv. Tutorials

184

View full text Add to dashboard Cite

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“…The BER measurement is instrumental in quickly determining the receiver's success in decoding the data. Small BER rates can be tolerated in systems that employ error correcting codes [17], [18]. …”

Section: Analysis Frameworkmentioning

confidence: 99%

Doppler estimation and correction for shallow underwater acoustic communications

Perrine

Nieman

Henderson

et al. 2010

2010 Conference Record of the Forty Fourth Asilomar Conference on Signals, Systems and Computers

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Reliable mobile underwater acoustic communication systems must compensate for strong, time-varying Doppler effects. Many Doppler correction techniques rely on a single bulk correction to compensate first-order effects. In many cases, residual higher-order effects must be tracked and corrected using other methods. The contributions of this paper are evaluations of (1) signal-to-noise ratio (SNR) performance from three Doppler estimation and correction methods and (2) communication performance of Doppler correction with static vs. adaptive equalizers. The evaluations use our publicly available shallow water experimental dataset, which consists of 360 packet transmission samples (each 0.5s long) from a five-channel receiver array.

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“…by replacing H n by the channel estimate H n in (3) and (4). Based on Gaussian approximation of the MMSE estimation error, we can compute an extrinsic LLR for { c…”

Section: Ce-based Mmse Turbo Equalizermentioning

confidence: 99%

“…In [3], in order to reduce the effects of channel estimation error, second-order statistics of the channel estimation error were incorporated in the equalizer. The application of TEQ to underwater acoustic communication was considered in [4] and an intensive experimental study on TEQ is presented in [5]. Recently, the structure of TEQ was extended to the case of a multiple transmitter system and space-time coding [6].…”

Section: Introductionmentioning

confidence: 99%

Practical application of turbo equalization to underwater acoustic communications

Choi

Riedl

Kim

et al. 2010

2010 7th International Symposium on Wireless Communication Systems

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In this paper, we describe linear turbo equalizers (TEQ) and investigate their practical application to underwater acoustic communications. Owing to the ability to achieve a good performancecomplexity trade-off, linear TEQ is a good candidate for long reverberant channels, which usually demand high computational complexity. First, we reveal a relationship between two different TEQ structures; channel estimate (CE)-based minimum mean square error (MMSE) TEQ versus direct-adaptive linear TEQ. We show that without inclusion of the second-order a priori statistics, the coefficients of direct-adaptive TEQ converge to linear timeinvariant form, though an optimal MMSE solution derived from a priori information is time-variant. Nevertheless, the direct-adaptive TEQ yields performance comparable to the CE-based MMSE TEQ while maintaining lower complexity. This was confirmed through real experiments conducted off the coast of Martha's Vinyard, MA ("SPACE 08"). We also discuss a practical design of a multi-channel least mean square (LMS) TEQ and experiments show that the LMS-TEQ successfully decodes data achieving up to 19.53 kbit/s for 1000 meter distance.

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Underwater communication link with iterative equalization

Cited by 26 publications

References 6 publications

Communicating Using Spatial Mode Multiplexing: Potentials, Challenges, and Perspectives

Communicating Using Spatial Mode Multiplexing: Potentials, Challenges, and Perspectives

Doppler estimation and correction for shallow underwater acoustic communications

Practical application of turbo equalization to underwater acoustic communications

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