Will the 1-bit GNSS receiver prevail?

In the context of satellite-based positioning, the problem of range-estimation with low resolution analog-to-digital conversion (ADC) is considered. While ADC with coarse output resolution degrades the positioning performance of Global Navigation Satellite System (GNSS) receivers, it's simplicity allows to realize sampling at high spatial and temporal rates in an energy and hardware efficient way. Therefore, here the achievable range-estimation accuracy of GNSS receive systems with 1-bit ADC resolution, multiple antennas and high receive bandwidths is analyzed. For different scenarios, including multi-path propagation and the presence of broadband interference, we investigate the scaling behavior of the estimation performance when increasing the number of receive antennas or the sampling rate. Results for all considered scenarios show that if a moderately higher number of antennas or a moderately faster temporal rate is used, 1-bit GNSS receive systems have the potential to outperform ideal receivers with infinite ADC resolution. This insight emphasizes that a receiver architecture with 1-bit ADC has the potential to play an important role for future low-cost receivers as well as for sophisticated energy efficient high-performance GNSS systems.

I. Introduction

The development of high-performance GNSS receive systems becomes challenging if one imposes strict constraints on the available power, chip-size or money budget. As the operation of critical infrastructure like mobile communication systems, electric distribution networks or financial trading systems can depend on correct time synchronization attained through a GNSS receive system, robustness against interference and multi-path propagation is another important requirement that should be met by the receiver design without violating the limitations defined by the available hardware. Under the assumption, that the receive system operates on the basis on an efficient estimation algorithm, two fundamental design options exist in order to attain higher positioning accuracy and robustness against channel imperfections like multi-path propagation or interference. One is to extend the amount of receive antennas, the other is to implement a higher receive bandwidth through a faster temporal sampling rate. However, these alternatives both increase the complexity of the receiver, especially as the ADC forms a bottleneck when heading at a low-complexity design [1]. With multiple receive sensors each antenna requires it's own radio front-end and therefore an individual ADC. High temporal sampling rates become inefficient at high amplitude resolution with output bits as the power dissipation of the ADC increases exponentially .