Built-In Self-Test for 3rd-Generation Mobile Users John Sunwoo Electrical and Computer Engineering Department Auburn University, AL
Smart Phones • Download mp3 files and listen. • Online shopping • Online gaming • GPS • Mobile pay • Wireless Key • Start the car
Paying School Tuition Are you sure you are paying $5,000, not $50,000?
Objective • Extensive usage of data transmissions via mobile devices • Tx/Rx of critical data • Make sure your mobile phone has no fault • Users need to have access to high-level functional test • The testing operation should be easy • BIST for users
History of mobile communications • 2G has limited data capability
Cellular network • Base station is located each cell • Base station has physical connection to phone/data line • One user connect to other users via base stations
TDMA vs CDMA • TDMA: Time Division Multiple Access • Allows a number of users to access RF channel without interference by allocating unique time slots to each user within each channel • CDMA: Code Division Multiple Access • Every communicator will be allocated the entire channel all the time by having different code than the others
2G to 3G… Test challenges? • 3G testing are related to the fact that it is fundamentally different than testing 2G networks • Adjustment with just a power meter. (2G) • Scan multiple neighboring base stations for interference that may affect network performance. (3G)
Model • Samsung SPH-I500 PDA Phone • $500 ~ $600 • CDMA 800Mhz/1900Mhz • Built-in memory 32MB
Inside • CDMA Processor • Base band-to-radio frequency transmit processor • IF-to-base band processor • RF-to-IF processor
My BIST Approach • Test control: Via USB • TPG: CDMA processor • ORA: CDMA processor • DUT: Transceiver circuitry • RFT3100 -> Power amplifier -> RFR3300 -> IFR3300
Plan -BIST start-No need of additional hardware within certain assumptions. (Making assumptions means the design is could be very vague)-Is it an effective test? (Diagnostic resolution)
How did others tested RF device? • Dr. Chatterjee • Test point insertion algorithm for determining the best nodes for sensor insertion • Sensors outputs can predict system and module specifications • Area overhead < 15%
Drawbacks • John have never took RF classes. (Major) • Qualcomm never responds my email for asking the actual data sheet of the MSM5100 modem.
Conclusions • The applicability of the presented BIST has only for the higher-level model • Mainly useful for hard faults such as spot defects rather than parametric faults. • Only applicable in a stable production process or after the production. • Exactly what consumer want
Good and Bad • Avoids affecting the internal RF parts to noise or external disturbances. • Fault diagnosis is not possible.
Future work • Bluetooth Testing • 2.4GHz • No published paper on Bluetooth BIST