Portable RF Multimedia Transmitter

Portable RF Multimedia TransmitterGroup 58Michael Bieniek, Mikhail Zakharov, Consultant: Dr. Vincent Gaudet1Vast majority of consumer media content is stored digitally on computers.

Consumers would like to see their media content on a TV.Background2TechnologyProsConsWire

CheapNot always feasibleWi-Fi basedExiting infrastructureSmart TVsQoSCostSetupCustom Transmitter & Receiver

QoSCostSetupCommon existing methods3Every TV has a wireless tuner to receive broadcast TV

Not all channels occupied by stations

FCC regulation allows for licence-free low power broadcast within the UHF bandBackgroundFCC Part 15.216 states that to operate in the UHF range you must comply with the following:Cant output more than 50 mW.Must include a disclaimer that the customer can see.

4Investigate feasibility of building a low-power portable transmitter, operating within the UHF band.Living room equivalent of FM transmitters for listening to music in the carPurpose

5Minimize hardware costs Scalability: point to multipointUtilize existing infrastructureEase of setup

Advantage6Wirelessly broadcast audio and video.

Receive on a TV.

Tune to a UHF channel.

Design Objectives7CriteriaDigital (ATSC)Analog (NTSC + BTSC)High DefinitionYesNoQoSBetterAverageExisting infrastructureAverageBetterImplementation complexityHighMediumCostHighLowBroadcast method8Support commonly used digital media storage formats (H.264, MPEG 2, MPEG 4, etc).USB for power and PC interfacing.Portable form-factor ready.

Design Objectives

Reference: Dell Unveiled USB Digital TV Tuner [online], Available: http://www.mr-gizmo.com/tag/digital-tv-tuner/9Design

10Design: User PC

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Prototype User InterfaceGStreamer: Video Pipeline

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Design: Digital Media Processor14

Digital Media Processor Prototype Platform: BeagleboardRef: Beagleboard.org15

Design: RF Transmission16Input: NTSC video and BTSC audio.Output: UHF modulated signal.Freescale MC44BS373CA.Capable of modulating on channels 14-69 (471.25 MHz 801.25 MHz).

RF Modulator

17Input: 2-channel analog audio.Output: Stereo encoded audio.Freescale MC44C402.BTSC Stereo Encoder

18FilterFilter ResponseImplementation

19Two stage amplifier boosts the power level of the RF modulated signal.Total simulated gain of 44 dBHigh IP3 points and unconditionally stable.Amplifiers

Mini-Circuits RF Amplifier20

Prototype PCB21Prototype Implementation

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Testing and Results23Testing and ResultsSpectrum Analyzer OutputParameters

Power (dBm)Actual-11Simulated10Maximum (FCC)1724Use digital modulation techniques (ATSC). Improve output power. Minimize size. $38/unit.

Commercialization Proposal

Reference: Dell Unveiled USB Digital TV Tuner [online], Available: http://www.mr-gizmo.com/tag/digital-tv-tuner/25Questions?

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