1 / 22

Robert Gibb Dominic Emilian Patrick Coletti Seth Berggren

Robert Gibb Dominic Emilian Patrick Coletti Seth Berggren. Outline of Presentation. Motivation Requirement Specifications PDR Concerns System Design Measurements Accomplishments Future Goals. Motivation. Current digital cable systems:

penn
Download Presentation

Robert Gibb Dominic Emilian Patrick Coletti Seth Berggren

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Robert Gibb Dominic Emilian Patrick Coletti Seth Berggren

  2. Outline of Presentation • Motivation • Requirement Specifications • PDR Concerns • System Design • Measurements • Accomplishments • Future Goals

  3. Motivation • Current digital cable systems: • Long, clumsy coax cable laid out throughout walls of the house are unsightly and difficult to route around your house • Broken coax can be difficult to replace • Splitting of coax cable requires additional wires • Awkward jack placement • One receiver box per TV

  4. Requirements Specifications • Cost: Under $200 • Size: Transmitter box should be 8x6x2 or smaller. Receiver will be small enough to plug right into back of TV. • Easy : Omni-directionally transition, simple setup, easy to use interface • Multiplicity: transmit separate channels to up to four different TVs. • Security: Password protected user accounts on server, parental control • Legality: YES, OUI, CI • Ability: work at distances up to 150 feet.

  5. Analog vs. Digital • Why should we implement with analog schemes rather than routing cable signal digitally? • Already in original form • Cuts down on hardware, already QAM tuner in TV • Digital system would involve constructing digital tuner • QAM tuner will directly decode incoming signal Packets HDMI Receiver

  6. White Spaces • Potentially utilize white spaces in the future • White Spaces Coalition allows unlicensed access to no longer used analog TV spectrum • Devices detect unallocated range of spectrum and utilize frequency spectrum in these ranges

  7. Design Solution: Complete System Block Diagram To Router

  8. Transmitter Baseband I/Q 1. RF Cable RF Antenna Out 2. 3. 4. -2400+TV[0:3]offset 2400+TV[0:3]offset -56MHz 56MHz -112MHz 112MHz 2. 1. 3. 4..

  9. Design Solution: Receiver RF TV In 1. 2. 3. RF Antenna In Baseband I/Q -2400+TV[0:3]offset TV[0:3]offset -56+TV[0:3]offset 56+TV[0:3]offset 2400+TV[0:3]offset 2456 1. 3. 2.

  10. Feasibility Study: RF Link Budget • RF Link Budget (Transmitter Power Required) • Ptx = Prx – Gtx –Grx + Lfs +Lm • Antenna Gain: Gtx, Grx = 6dBi • Free Space Loss: Lfs = 20log(4pi*D*f/c) = 73dB • Fade Margin: Lm = 30dB max Ptx < 30dbm Prx = Noise Floor + NF_rx + SNR = -113dbm + 2.6dB + 35dB Ptx = -113dbm + 2.6dB +35dbm - 6dbi – 6dbi + 73dB +30db = 15.6 dbm Many calculators already available

  11. Prototype One: Reception with Channel Change • Channel Change with VCO at Tx, Synthesizer at Rx

  12. Initial Problems with Prototype One • Wireless System was noisy • Antenna bandwidth? • Phase Noise? • Cable input (-36dbm) too low? • Several things to try: power amplifier, phase-locked loop, shift • Vestigial sidebands out of antenna attenuation range Hantenna

  13. Measurements: Frequency Counter • Frequency vs. Tuning Voltage • Deviations from linear due to power supply (breadboard)

  14. Measurements: Spectrum Analyzer • Tuning VCO (with Spectrum Analyzer) • Power at front end and Noise Floor

  15. Measurements: Spectrum Analyzer • Measured Output of DVD Player • Channel 3: 55.5MHz @ -36.3dbm • Channel 4: 60.866MHz @ -36.3dbm • Using Vtune = 4.5, recorded reception/frequency deviation • Established reception with synthesizer frequency +-1MHz

  16. Review MDR Specs • From PDR, we said we would have: • Established access to all available channels for one TV • Established a working interface between BeagleBoard and MCU to select a given cable channel. • New MCU already contains the functionality of BeagleBoard - don't need it • No need for an interface either • After PDR, new goals were created • Establish access to all available channels for one TV • Establish working SPI connection with Evaluation Board and a slave device • Ensure HTML hosting functionality.

  17. Prototype One: MDR Demonstration • Added: • Phase-Locked 2.4GHz Local Oscillator at transmitter • Power amplifier prior to transmitter IF input • Reception clear • Proof of concept achieved

  18. EVK1100 Functionality • Using a static IP, one can connect to hosted Web page • Can monitor different actuators on the board • Can control board peripherals Web Server

  19. PCB Design • PCB Fabrication • EAGLE Layout Editor to create custom printed circuit boards for design • Design parts in EAGLE: ADRF6806, MAX2831, ADL5386 • Transmitter: 1PCB • Receiver: 4 separate PCBs

  20. Spring 2012 Gantt Chart

  21. Comprehensive Design Review • Things to get started on right away • Completing PCB Design and having sent out for fabrication • Get Web server to control SPI port and send commands • Allow multiple users to access website via DHCP • By CDR we will have: • Implemented analog transmitter and analog receiver units with custom PCBs • A fully functional multi-user web host with full control over SPI communications

  22. Team Roles • Robert Gibb – Hardware Interfacing, Low Level Software Design • Dominic Emilian – Transmitter Design, PCB Design • Patrick Coletti – Web Server • Seth Berggren – Receiver Design

More Related