Communications Baseband PDR Communications Baseband Project 05500 Communications
Communications Baseband PDR Communications Baseband Project 05500
Communications Baseband PDR Members ¨ Advisors: § Dr. Joe Delorenzo § Dr. Eli Saber § Dr. Sohail Dianat ¨ Team Members: § Leland Smith (Team Leader) § Jason Riesbeck (Chief Engineer) § Jonathan Hutton
Communications Baseband PDR Introduction ¨ Communications Baseband is a project created by several professors in order to stimulate student’s practical understanding of communication systems. ¨ Sponsor: Rochester Institute of Technology Department of Electrical Engineering
Communications Baseband PDR Project Overview ¨ Modulate/Demodulate using Amplitude Modulation, Frequency Modulation, and Pulse Code Modulation ¨ Receive analog or digital transmission approximately a classrooms distance and demodulate ¨ Output original signal to see/hear successful recovery
Communications Baseband PDR Team Work Breakdown
Communications Baseband PDR Fundamental Design Objectives Specifications Can be completed in allotted time. Weight 10 Communicates AM, FM, and PCM across a classroom 9 Suitable for evaluation in a laboratory 7 Affordable for customer. 6 Easy to Use. 4 Minimal amount of external equipment 4
Communications Baseband PDR Preliminary Design Concept #1 Universal AM/FM/ASK/FSK System ¨ ¨ ¨ • Two distanced RF channels • Digital and analog signals utilize common modulators Digital data rate Not truly PCM Usefulness ¨ Versatile
Communications Baseband PDR Preliminary Design Concept #2 Analog Voice and Wireless RS 232 ¨ ¨ ¨ Not a PCM solution Requires extra lab equipment Duplex communication ¨ • Analog AM and FM maintained • Serial link established Reasonable Bandwidth
Communications Baseband PDR Preliminary Design Concept #3 Analog Voice and Wireless USB • Analog AM and FM maintained • USB link established ¨ ¨ ¨ Difficult to implement Requires extra lab equipment Duplex communication ¨ ¨ Impressive Bandwidth 1. 5 - 450 Mbps
Communications Baseband PDR Preliminary Design Concept #4 Analog Voice and Streaming PCM Audio • All modulations have independent communication systems • All schemes have a common audio source ◦Impressive Bandwidth ◦Comparison of modulation schemes ◦No external equipment
Communications Baseband PDR Concept Analysis
Communications Baseband PDR System Development • Divided into 12 subsystems • Specification developed for each
Communications Baseband PDR Feasibility ¨ Assessed at a subsystem level. ¨ Depends on the resources available ¨ To maintain feasibility, subsystems should: § Satisfy design objectives § Economical § Comply with time constraints
Communications Baseband PDR FCC Considerations Unlicensed Bands (FCC 15. 247. b. 4) Country Frequency Notes Standards US 2. 400 -2. 483. 5 GHz ISM Band 1 W 802. 11/11 b 902 -928 MHz ISM Band (Used by GSM in most countries) 5. 800 -5. 925 GHz ISM Band 5. 15 -5. 25 GHz U-NII (Unlicensed - National Information Infrastructure) max. 200 mw EIRP 802. 11 a 5. 25 -5. 35 GHz U-NII max. 1 w EIRP 802. 11 a 5. 725 -5. 825 GHz U-NII max. 4 w EIRP 802. 11 a Antenna gain can be as much as 6 d. B. All other bands 100 m. W or less
Communications Baseband PDR Audio Subsystem ¨ Block Diagram
Communications Baseband PDR Anti-Aliasing Filter ¨ Specifications: § § 0 -5 V Input Pass-band 20 k. Hz Stop-band 22 k. Hz Attenuation 20 d. B ¨ Butterworth Filter ¨ Elliptical Filter
Communications Baseband PDR Low Pass Filter -17 d. B 22. 1 k. Hz
Communications Baseband PDR AM Modulation ¨ Concept Development § Discrete Parts § IC § Transceiver IC ¨ Feasibility Assessment
Communications Baseband PDR Design Objectives and Synthesis ¨ Clock Oscillator § 1 MHz Sine Wave § RLC Filter
Communications Baseband PDR Clock Oscillator
Communications Baseband PDR AM Receiver ¨ AM Receiver § Demodulates Signal § Amplifies the Signal by 18 d. B
Communications Baseband PDR FM Systems Transmitter Receiver ¨ Complicated to engineer ¨ Could take months in industry
Communications Baseband PDR Radio IC’s ¨A simple and effective solution
Communications Baseband PDR Choosing an FM IC Objectives Part availability Weight 10 Comprehensive design resources 8 Application examples 7 Performance 6 Price 5 Low parts count 5
Communications Baseband PDR FM Feasibility Task Time in Hours Schematic Creation 15 Performance Analysis 5 Specification Formation Parts List 13 8 General Documentation 10 Board Layout 12 Board assembly 7 Functional Test 12 Integration 4 Tweaking and Repair 20 Total 106 Completed 51 Remaining 55 • Meets design requirements • Able to be complete in allotted time • Low cost
Communications Baseband PDR FSK Systems ¨ Similar to analog FM systems ¨ Also very complicated
Communications Baseband PDR FSK Feasibility Nordic NRF 2401 • Transmits data at 1 Mbps • 2. 4 GHz ISM band
Communications Baseband PDR FSK Link Analysis ¨ NRF 2401 Specification ○ 0 d. Bm output power ○ -80 d. Bm receiver sensitivity ¨ Link Budget Analysis ○ 60 d. B of attenuation at 10 m (with 0 d. B antenna gain)
Communications Baseband PDR FSK Feasibility Task Time in Hours Part Research 8 Schematic Creation 7 Performance Analysis 5 Specification Formation 8 Parts List 8 Timing Information 10 Board Layout 12 Board assembly 7 Functional Test 13 Integration 15 Tweaking and Repair 20 Total 113 Completed 46 Remaining 67 • Meets project needs • Only $4 with few external parts • Reasonable time budget
Communications Baseband PDR PCM and Control Subassembly ¨ Transmit Side § Conversion of Analog to Digital § Apply Protocol to Digital Data § Manage Memory and Data Flow to FSK Chip ¨ Receive Side § Provide Control to FSK Chip § Receive and Manage FSK Chip Data § Control and Send Data to DAC
Communications Baseband PDR Interface Specifications ¨ Rail to rail (0 -3. 3 V) analog signal input ¨ Desire ~44 k. Hz Sample Rate ¨ 1 Mbps transmit rate to FSK chip ¨ Send samples to Digital to Analog Converter at sample rate
Communications Baseband PDR Microcontroller Specifications ¨ At least 10 I/O pins ¨ UART (clocked serial data transfer) ¨ Support 1 Mbps
Communications Baseband PDR Solutions ¨ PICmicro ¨ Analog Microcontroller Devices DAC § 10 -bit § No overhead bits § Serial
Communications Baseband PDR Capabilities ¨ PIC offers 10 -bit AD ¨ PIC provides I/O ports § USART (Synchronous/Asynchronous Communications) § Many I/O Ports for control lines § Provides 1 MHz USART ¨ Data storage and management
Communications Baseband PDR System Diagram
Communications Baseband PDR Communications Protocol ¨ PIC must manage data from 10 -bit samples to exact 1 Mbps output ¨ USART sends 8 -bit words ¨ Start and Stop bit ¨ Must hold at least 2 samples in PIC memory to transfer
Communications Baseband PDR IN PIC OUT ¨ Known: What goes in must come out – and at the same rate. ¨ Therefore: The rate the PIC can sample at is governed by the FSK communications protocol. ¨ Sampling rate must be some integer number of the outgoing packet rate
Communications Baseband PDR Protocol Options Protocol Type FSK Chip Mode Synchronous Shock. Burst Asynchronous Direct
Communications Baseband PDR Synchronous Option
Communications Baseband PDR Asynchronous Option 1
Communications Baseband PDR Asynchronous Option 2
Communications Baseband PDR Choice Protocol ¨ Asynchronous – 1 Sample per 2 Frames
Communications Baseband PDR The Plan for May ¨ Purchase all components ¨ Build systems to spec ¨ Test individual systems ¨ Integrate Systems
Communications Baseband PDR Preliminary Cost Analysis Item Board Layout Price ($) 100 FM Transmitter Parts 40 FM Receiver Parts 30 GFSK Transceiver Parts 30 Audio Section parts 25 AM Receiver Parts 30 AM Transmitter Parts 30 PIC Implementations 15 Power Supply 15 RF Cables 30 Misc. Prototype Materials 20 Total 365
Communications Baseband PDR Possible Upgrades
Communications Baseband PDR Questions?
Communications Baseband PDR Preliminary System Design
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