We propose Gaussian processes (GPs) as a novel nonlinear receiver for digital communication systems. The GPs framework can be used to solve both classification (GPC) and regression (GPR) problems. The minimum mean squared error solution is the expectation of the transmitted symbol given the information at the receiver, which is a nonlinear function of the received symbols for discrete inputs. G...

The security and reliability of GPS receivers are critical to Phasor Measurement Units (PMUs). These devices provide synchronized voltage and current phasor measurements in power systems based on GPS timing. However, due to the unencrypted nature and low received signal to noise ratio of civil GPS signals, jamming and spoofing attacks on GPS receivers can pose a risk to both the position and ti...

We report on a study of the carrier-phase time transfer boundary discontinuity by the use of the precise point positioning (PPP) technique. Carrier-phase time transfer is first compared with two-way satellite time and frequency transfer (TWSTFT) between the same stations. It matches TWSTFT quite well and provides better short-term stability. Later, we extract 1-day data-arc boundary discontinui...

The E-911 mandate from the Federal Communications Commission (FCC) requires a mobile 911 caller location to be established for 67 percent of calls to within 50 meters, and 95 percent of calls to within 150 meters for wireless handset-based solutions. To meet the E-911 requirement, a GPS receiver can be incorporated into mobile phones which use frequency modulated (FM) signals for communications...

The pseudolite system is a good alternative for indoor positioning systems due to its large coverage area and accurate positioning solution. However, for common Global Positioning System (GPS) receivers, the pseudolite system requires some modifications of the user terminals. To solve the problem, this paper proposes a new pseudolite-based indoor positioning system architecture. The main idea i...

Over the last decade, the 1-sample-per-second kinematic Global Positioning System (GPS) has been used as a displacement sensor in earthquake observations and for structural health monitoring. Many researchers in both seismology and engineering have expressed the desire for higher-sample-rate (10-sample-per-second or higher) GPS data to acquire high-frequency displacement information. We perform...

Logan Scott is a consultant specializing in radio frequency signal processing and waveform design for communications, navigation, radar, and emitter location. He has more than 24 years of military GPS systems engineering experience. As a senior member of the technical staff at Texas Instruments, he pioneered approaches for building high-performance, jammingresistant digital receivers using larg...