The Global Positioning System: A Shared National Asset (1995)
Chapter: SCENARIO 5: AIDED WIDE BANDWIDTH STANDARD ANTENNA
Scenario 2: Aided Y-Code Bandwidth With A Standard Antenna
For comparison purposes, a baseline of an aided Y-code bandwidth GPS receiver operating with a standard antenna will be used.
Scenario 3: Aided Y-Code Bandwidth With Nulling Antenna
For comparison purposes, a baseline of an aided Y-code bandwidth GPS receiver operating with a nulling antenna will be used.
Scenario 4: Unaided Wide Bandwidth With Standard Antenna
This scenario is compared with the baseline described in Scenario 1.
Receiver Thermal Noise Limited Case
In this condition, the four times higher radio carrier frequency will give a free-space carrier-to-noise ratio disadvantage of 12 dB. Above the code-tracking loop threshold, the 12 dB loss is more than offset by increased signal bandwidth. Multipath susceptibility is reduced by factors of 10 and 100, respectively, over Y-code and C/A-code.
Noise Jammer Limited Case
Importantly, any increase in free-space loss with frequency is equal for both the interference source and the GPS satellite. With the narrower code chip of the wide-band signal structure, better calibration of the constellation will be needed.
Scenario 5: Aided Wide Bandwidth Standard Antenna
The comparative baseline is the aided Y-code receiver operating with a standard antenna, Scenario 2.
Receiver Thermal Noise Limited Case
In this condition, the four times higher radio carrier frequency will give a free-space carrier-to-noise ratio disadvantage of 12 dB. Above the code-tracking loop threshold, the 12 dB loss is more than offset by increased signal bandwidth. Multipath susceptibility is reduced by factors of 10 and 100, respectively, over Y-code and C/A-code.
