Study of NVIS Channel for USN Protocol Definition in Antarctica

Maso, Josep Maria; Porte, Joaquim; Pijoan, J.L.; Badía, David

doi:10.3390/electronics9061037

Cited by 3 publications

(10 citation statements)

References 22 publications

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“…The design of the OFDM configuration requires a previous study of the channel to define every parameter. This channel analysis and definition of the OFDM configuration for high multipath is defined in a previous article [24]. Taking account the designed OFDM, first of all, bandwidth of the OFDM signal is 3 KHz as the HF standards.…”

Section: Orthogonal Frequency-division Multiplexing (Ofdm)mentioning

confidence: 99%

“…Taking account the designed OFDM, first of all, bandwidth of the OFDM signal is 3 KHz as the HF standards. The symbol length was calculated first with a value of 9.33 ms as in [24] to set the number of subcarriers. As a result of that, 28 subcarriers will be transmitted being one of them a DC null to avoid offset effects.…”

Section: Orthogonal Frequency-division Multiplexing (Ofdm)mentioning

confidence: 99%

“…The configuration designed makes every subcarrier to be about 107 Hz. Every frame packet is composed of 7 OFDM symbols with a duration of 86.31 ms, which are obtained due to the coherence time (10 s) [24]. One of the OFDM symbols is a pilot to estimate the channel to perform the zero-forcing equalization which is calculated as we can see in (6).…”

Section: Orthogonal Frequency-division Multiplexing (Ofdm)mentioning

confidence: 99%

“…The delay spread is a key measure of the multipath received, being the time between the first and the last path received. In [24] this was already calculated for an NVIS channel, and its value is 2.75 ms, for that reason the cyclic prefix is calculated in relation to this value, adding a small leeway. Finally, 3 ms of copied useful data inserted at the beginning of the OFDM symbol (CP) avoid the interferences between neighbor symbols produced by the multipath of the channel.…”

Section: Orthogonal Frequency-division Multiplexing (Ofdm)mentioning

confidence: 99%

“…The summary is shown in Table 2. Each transmission includes a 6th PN sequence with a resampling of 8 and 5 ms length as in [24] that is used to synchronize the demodulation of the frames. The PN sequence has been designed not to be affected by the delay spread and Doppler shift.…”

Section: Frame Protocol and Tests Designmentioning

confidence: 99%

See 4 more Smart Citations

NVIS Multicarrier Modulations for Remote-Sensor Applications

Maso

Gonzalez

Male

et al. 2020

Sensors

Self Cite

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The number of Internet of Things (IoT) devices has experienced a large growth during the last decade, as well as the data volume gathered from remote sensors. Satellites are still a suitable communication method and may be preferable for a remote ubiquitous sensor network (USN), which sometimes are located in places without much communications infrastructure where coverage is the principal drawback. Alternatively, the proposed solution for this article aims at a near-vertical incidence skywave (NVIS) channel for high frequencies (HF) with a low-cost platform, allowing a low-power transmissions coverage area up to 250 km for USN. The HF standards are focused on generic communication channels not being robust for NVIS communications. In this article we study and test an alternative based on orthogonal frequency-division multiplexing (OFDM) modulations to make them more robust and less dependent on the channel NVIS communications. For that purpose, we test the HF standard modulations and a designed OFDM modulation to prove the robustness of each. This study has been tested between Barcelona and Tarragona, using different transmission power levels and modulation orders.

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Section: Orthogonal Frequency-division Multiplexing (Ofdm)mentioning

confidence: 99%

Section: Orthogonal Frequency-division Multiplexing (Ofdm)mentioning

confidence: 99%

Section: Orthogonal Frequency-division Multiplexing (Ofdm)mentioning

confidence: 99%

Section: Orthogonal Frequency-division Multiplexing (Ofdm)mentioning

confidence: 99%

Section: Frame Protocol and Tests Designmentioning

confidence: 99%

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NVIS Multicarrier Modulations for Remote-Sensor Applications

Maso

Gonzalez

Male

et al. 2020

Sensors

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Escaping the Dead Zone: a Bottleneck in Humanitarian Ionospheric Radio Communications

Witvliet¹

2021

2021 IEEE Global Humanitarian Technology Conference (GHTC)

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High Frequency (HF) radio communications are used in humanitarian work in areas where local networks are non-existent, or destroyed by natural disaster or human conflict. Direct point-to-point communications are realized over long distances, independent of local networks, using the ionosphere as a natural high-altitude reflector. HF ionospheric radio is essential for humanitarian organizations delivering basic healthcare in poor and remote areas. Normally, with proper frequency planning, ionospheric radio will easily connect all field teams in a contiguous area with a radius of 200-400 km. However, in recent years humanitarian organizations reported a "Dead Zone" that occurs at a short distance from the base, with good reception at larger distances. This local communication blackout causes a security hazard to the field crews. This paper investigates the phenomenon, and makes an inventory of its possible causes and drivers.

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SC-FDE Layer for Sensor Networks in Remote Areas Using NVIS Communications

et al. 2021

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Despite high costs and lengthy deployments, satellite communications have traditionally been used to provide coverage in remote areas. However, given the fact that there is no radio infrastructure available in these areas, Near Vertical Incidence Skywave (NVIS) technology has positioned itself as an attractive alternative to communicate with low-power nodes in remote areas. This type of communication works in the HF frequency range complying with STANAG and MIL-STD standards, which define a physical layer for scenarios that differ from NVIS and low-power communication. The purpose of this paper was to present the definition of a new communication physical layer based on single-carrier frequency-domain equalization (SC-FDE) based on these standards but adapted to the ionospheric communication channel. This physical layer was compared to an OFDM-based layer from a previous study. The experiments performed show that this new approach achieves better results than OFDM in terms of a higher signal quality with a higher specific BER probability. Finally, this layer was also used in the theoretical design of an NVIS gateway to link sensor network devices spanning large-scale remote areas in a secure manner in the context of ubiquitous sensor networks (USN).

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Study of NVIS Channel for USN Protocol Definition in Antarctica

Cited by 3 publications

References 22 publications

NVIS Multicarrier Modulations for Remote-Sensor Applications

NVIS Multicarrier Modulations for Remote-Sensor Applications

Escaping the Dead Zone: a Bottleneck in Humanitarian Ionospheric Radio Communications

SC-FDE Layer for Sensor Networks in Remote Areas Using NVIS Communications

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