· Introduction, FCC Regulations for E911, Wireless Location + GPS + Communications
· Estimate 2 Million chipsets shipped per month in 2003
· 100's of millions of users by end of decade
· RF Propagation
· Discussed Indoor location problems, lower SNR, large errors, reflected signals
· HSGPS and AGPS methods of improving availability
· Long signal dwell form 5ms up to 120ms
· Longer coherent integration via bit prediction in combination with non-coherent signal accumulation
· AGPS - assisted GPS, cell net passes ephemeris, GPS time, approximate position.
· Benefits
· Improves sensitivity using long dwell of 20 to 500ms
· Signal measured to -185dBw
· Indoor positioning and improved TTFF
· Urban Canyon Testing
· Results using high performance receiver - sparse availability
· Sirf HS (high sensitivity) - good availability, heavily filtered causing problems in corners, across track error up to 100m.
· Sirf HS combined with muRata Gyro - better availability and accuracy, but poor GPS position still affects position accuracy.
· Indoor Test Barn
· Wood -asphalt roof attenuated GPS signal by 5 to 12dB. Good results demonstrated from Sirf HS in standalone and DGPS modes.
· Indoor Location - Residence
· Basement Garage - concrete roof tiles, wooden garage door. GPS signal attenuated by 20-25dB.
· Availability good, position to 10m RMS.
· U of C Simulation Capabilities
· Is it possible to use a simulator to reproduce an indoor signal environment?
· Studies at U of C are progressing to create models to simulate the indoor environment for standardized testing of receivers.
· Conclusions - best solution is combination of high sensitivity receivers and self-contained sensors.
· Closing remarks and audience questions
· Interested attendees were then given a tour of the Navigation Lab facilities and Antenna Range at CCIT
