EBEM MODEM PDF

Enhanced Bandwidth Efficient Modem. (EBEM) Cryptographic Module. Non- Proprietary Security Policy. Document Number , Rev. ViaSat will provide the Army with MD(U) strategic EBEM and This modem uses advanced modulation and coding technology to. ViaSat Inc. (Nasdaq:VSAT) demonstrated its DISA certified MD Enhanced Bandwidth Efficient Modem (EBEM) to members of the U.S.

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A FEC decoder decodes the Forward error correction code that is used in the specific signal. A modulator is generally a much simpler device than a demodulator, because it doesn’t have to recover symbol and carrier frequencies.

EBEM – Enhanced Bandwidth Efficient Modem | AcronymFinder

When differential coding is used, the data are deliberately made to depend not only on the current symbolbut also on the previous one. If the analog signal was digitized without a four-quadrant multiplier, the complex envelope has to be calculated by a digital complex mixer. A descrambler restores the original stream from the scrambled one. The main functions of a satellite modem are modulation and demodulation.

VIASAT GETS $4.6 MIL ORDER FOR MD-1366 EBEM MODEMS.

Data to be transmitted are transferred to a modem from Data terminal equipment e. High-end modems also incorporate some additional features:.

The input signal for the analog tract is at the intermediate frequency or in the L-bandin the second case it must be firstly converted to IF.

Similarly, a signal received from a satellite is firstly downconverted this is done by a Low-noise block converter – Ebfmthen demodulated by a modem, and at last handled by data terminal equipment. This article does not cite any sources. Satellite modems are often used for home internet access. A block diagram of a generic satellite modem is shown on the image. They are appropriate only when certain conditions apply: There are some devices that include only a demodulator and no modulator, thus mofem allowing data to be downloaded by satellite that are also referred to as “satellite modems.

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A number of features and choices remain when considering wireless networking equipment like the satellite communications modems that form the backbone of many wireless networks. During a demonstration, the EBEM has shown its seamless, error-free adaptation to data rates from 28 to over Mbps without operator intervention. Retrieved from ” https: Satellite data unit Satellite dish Satellite modem Satellite phone Spacebus Very-small-aperture terminal.

Department of Defense telecommunication transmission policy is to simplify its integrated wireless networks. Sometimes a digital automatic gain control circuit is implemented in the demodulator. Using different modems that have an open-standard waveform, but proprietary baseband interfaces is just as ineffective as using two different proprietary modems. A multiplexer transforms several digital streams into one stream.

Known turbo codes at reasonable block size and complexity can come quite close to the Shannon channel capacity limit within about 1 to 2 dB.

In most cases frequency has to be converted using an upconverter before amplification and transmission. Articles lacking sources from October All articles lacking sources. Differential coding is used to resolve this ambiguity. October Learn how and when to remove this template message.

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Satellite communication standards also define error correction modej and framing formats. The primary additions to the new standard include government approved TRANSECadvanced modulation and forward error correction techniques, and enhancements specific to IP network-centric operation. Then the signal is either sampled or processed by the four-quadrant multiplier which produces the complex envelope components I, Q through multiplying it by the heterodyne frequency.

Demonstrations of the modem have shown the value of the new modulation morem coding choices. For well-groomed transponders, PCMA can be of value, but to a lesser degree. Please help improve this article by adding citations to reliable sources.

If mofem power decreases, ITA ehem automatically and dynamically decreases the link data rate using more robust waveforms to maintain the link connection. This is achieved by the following two circuits:. Views Read Edit View history. Then its frequency is converted if needed.

At the same time, the Department of Defense wants to continue to encourage innovation. A demodulator is one of the most important parts of the receiver. These new capabilities enable you to manage your communications resources and choose whether you maximize data throughput, enable more users to access the network, or decrease networking costs.