5 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
6 History of mobile communications - 2G has limited data capability
7 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
8 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
9 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)
13 Inside ► CDMA Processor ► Base band-to-radio frequency transmit processor ► IF-to-base band processor ► RF-to-IF processor
14 My BIST Approach ► Test control: Via USB ► TPG: CDMA processor ► ORA: CDMA processor ► DUT: Transceiver circuitry RFT3100 -> Power amplifier -> RFR3300 -> IFR3300
15 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)
16 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%
18 Drawbacks ► John have never took RF classes. (Major) ► Qualcomm never responds my email for asking the actual data sheet of the MSM5100 modem.
19 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
20 Good and Bad ► Avoids affecting the internal RF parts to noise or external disturbances. ► Fault diagnosis is not possible.
21 Future work ► Bluetooth Testing 2.4GHz No published paper on Bluetooth BIST