We present a general problem formulation for optimal parameter estimation based on quantized observations, with application to antenna array communication and processing (channel estimation, time-of-arrival (TOA) and direction-ofarrival (DOA) estimation). The work is of interest in the case when low resolution A/D-converters (ADCs) have to be used to enable higher sampling rate and to simplify the hardware. An Expectation-Maximization (EM) based algorithm is proposed for solving this problem in a general setting. Besides, we derive the Cramér-Rao Bound (CRB) and discuss the effects of quantization and the optimal choice of the ADC characteristic. Numerical and analytical analysis reveals that reliable estimation may still be possible even when the quantization is very coarse.

This paper presents the performance analysis of signals from the Galileo satellites in the E1 and E5a frequency bands and GPS L5 signals as measured by DLR's experimental ground-based augmentation system. The results show that the raw noise and multipath level of Galileo signals and of the GPS L5 signals are smaller than that of GPS L1. The new signals are also less sensitive to the choice of carrier-smoothing time constant. Furthermore, the inter-frequency biases that affect dual-frequency processing are investigated. These biases differ between satellites and depend on satellite and receiver hardware, but they can be determined a priori. With known receiver and antenna configurations, it is possible to correct for these biases. A residual uncertainty associated with the bias correction has to be taken into account. This can be modeled as part of the ground and airborne bounding standard deviations (σ pr_gnd and σ pr_air ) used in GBAS processing.

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Modeling of both nominal distortions and signal anomalies (i.e., evil waveforms) is crucial for an accurate user error budget for satellite based augmentation systems (SBAS) and multi‐frequency multi‐constellation ground based augmentation systems (GBAS). Such analysis is of particular interest for the ongoing standardization work of L1‐L5 SBAS services. In this paper we propose a method to jointly estimate analog and digital distortion of a satellite navigation signal based on high gain antenna measurements. Joint estimation of analog and digital distortion is needed in case the estimates of these two satellite signal imperfections are interdependent. This is the case when the time‐bandwidth product of the satellite signal is small. The impact of both satellite imperfections on the ranging performance of a GNSS receiver is assessed by means of analytical formulations which make use of the cross‐power spectral density (CPS) between the distorted and the ideal signal and of the power spectral density (PSD) of the nominal (ideal) signal. Copyright © 2016 Institute of Navigation

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