LTE receiver design and multipath analysis for navigation in urban environments

Abstract

Mitigating multipath of cellular long‐term evolution (LTE) signals for robust positioning in urban environments is considered. A computationally efficient receiver, which uses a phase‐locked loop (PLL)–aided delay‐locked loop (DLL) to track the received LTE signals, is presented. The PLL‐aided DLL uses orthogonal frequency division multiplexing (OFDM)–based discriminator functions to estimate and track the time‐of‐arrival. The code phase and carrier phase performances in an additive white Gaussian noise (AWGN) channel are evaluated numerically. The effects of multipath on the code phase and carrier phase are analyzed, demonstrating robust multipath mitigation for high transmission LTE bandwidths. The average of the DLL discriminator functions over multiple LTE symbols is presented to reduce the pseudorange error. The proposed receiver is evaluated on a ground vehicle in an urban environment. Experimental results show a root mean square error (RMSE) of 3.17 m, a standard deviation of 1.06 m, and a maximum error of 6.58 m between the proposed LTE receiver and the GPS navigation solution over a 1.44 km trajectory. The accuracy of the obtained pseudoranges with the proposed receiver is compared against two algorithms: estimation of signal parameters by rotational invariance techniques (ESPRIT) and EKAT (ESPRIT and Kalman filter).

Editorial: In this issue

“…Experimental results show a root mean square error (RMSE) of 3.17 m, a standard deviation of 1.06 m, and a maximum error of 6.58 m between the proposed LTE receiver and the GPS navigation solution over a 1.44 km trajectory. The accuracy of the obtained pseudoranges with the proposed receiver is compared against two algorithms: estimation of signal parameters by rotational invariance techniques (ESPRIT) and EKAT (ESPRIT and Kalman filter) …”

“…The accuracy of the obtained pseudoranges with the proposed receiver is compared against two algorithms: estimation of signal parameters by rotational invariance techniques (ESPRIT) and EKAT (ESPRIT and Kalman filter). 13…”

Indoor Positioning Based on LTE Carrier Phase Measurements and an Inertial Measurement Unit

“…Several code phase-based receivers have been proposed to obtain the pseudorange measurements from LTE signals [13,[26][27][28]. Analytical and experimental results have shown that the performance of these receivers significantly degrades in multipath environments, making them practically unusable in indoor environments [14,17,29]. In this section, a receiver structure is proposed, which exploits the carrier phase measurements of LTE signals.…”

“…2 shows the block diagram of the proposed receiver. This receiver is adapted from the receiver developed in [14], which used a phase-locked loop (PLL)-aided delaylocked loop (DLL). Here, only phase tracking is performed (i.e., code tracking is not utilized) since it was observed experimentally that such tracking indoors degrades the receiver's performance.…”

“…Furthermore, the availability of these signals is not hindered by the emergency situation indoors (e.g., loss of power, fire, smoke, etc.). Cellular LTE and code-division multiple-access (CDMA) signals have been demonstrated in the recent literature to produce a meter-level-accurate navigation solution outdoors on ground-based receivers [11][12][13][14] and a centimeter-level-accurate navigation solution on outdoors aerial-based receivers [15,16].…”