Collaborative Cellular-Aided Inertial Navigation

This video presents the first experimental demonstration of multiple unmanned aerial vehicles (UAVs) aiding their on-board inertial navigation systems (INSs) by sharing mutual pseudorange observables extracted from cellular transmitters and communicating their own inertial measurement unit (IMU) data. While GPS is available, the UAVs use their INSs aided by GPS and cellular signals to navigate while simultaneously mapping the cellular transmitters. When GPS signals become unavailable, the UAVs navigate exclusively with their INSs aided by cellular pseudoranges while simultaneously mapping the cellular transmitters (i.e., performing centralized collaborative radio SLAM). Results demonstrate that the exploitation of free ambient cellular signals of opportunity (SOPs) in the environment significantly reduces INS errors in the absence of GPS.

 
Collaborative Cellular-Aided Inertial Navigation

 

Ground Vehicle Navigation with LTE Signals: SSS vs. CRS

This video presents ground vehicle navigation using two different reference signals in a semi-urban environment in long-term evolution (LTE) systems: the secondary synchronization signal (SSS) and the cell-specific reference signal (CRS). The transmission bandwidth of the SSS is less than 1 MHz, leading to low time-of-arrival (TOA) estimation accuracy in a multipath environment. The CRS is more robust in multipath environments due to its higher transmission bandwidth, which can be as high as 20 MHz. The navigation solutions estimated from the SSS only and from the SSS aided by the CRS are shown. For the SSS-only solution, a computationally-efficient receiver was designed. For the CRS-aided SSS solution, the channel impulse response was estimated using the CRS and used as a feedback into the SSS receiver tracking loops. The results show 5 times improvement in the root mean squared error (RMSE) by using the CRS-aided SSS receiver over the SSS receiver.

 
 
Ground Vehicle Navigation with LTE Signals: SSS vs. CRS

 

Cellular-Aided Inertial Navigation

This video presents the first experimental demonstration of an unmanned aerial vehicle's (UAV's) inertial navigation system (INS) being aided by a cellular signal of opportunity (SOP). While GPS is available, the UAV uses the INS aided by GPS and cellular signals to navigate while simultaneously mapping the cellular SOP. When GPS signals become unavailable, the UAV navigates exclusively with the INS aided by the cellular SOP while simultaneously mapping the cellular SOP (i.e., performing radio SLAM). Results demonstrate that the exploitation of free ambient cellular signals in the environment significantly reduces INS errors in the absence of GPS and bounds the INS drift.

Cellular-Aided Inertial Navigation

 

UAV Navigating with Cellular LTE Signals

This video presents the first experimental demonstration of a UAV navigating exclusively with cellular LTE signals. In this video, a DJI Matrice 600 is equipped with a cellular consumer-grade 800/1900 MHz omnidirectional antenna for receiving LTE signals. The LTE signals were down-mixed and sampled via an Ettus E312 USRP. Then, the signals were processed using the LTE software-defined receiver (SDR) developed by ASPIN Laboratory. The LTE navigation solution is compared to the UAV's true trajectory, which is obtained from the UAV's sensor suite (e.g., GPS, IMU, barometer, etc.).

UAV Navigating with Cellular LTE Signals

 

UAV Navigating with Cellular CDMA Signals

This video presents the first experimental demonstration of a UAV navigating exclusively with cellular CDMA signals. In this video, a DJI Matrice 600 is equipped with a cellular consumer-grade 800/1900 MHz omnidirectional antenna for receiving CDMA signals. The CDMA signals were down-mixed and sampled via an Ettus E312 USRP. Then, the signals were processed using the LabVIEW-based cellular CDMA software-defined receiver (SDR) developed by ASPIN Laboratory. The UAV is receiving information about ambient cellular signals from a reference station deployed in the University of California, Riverside campus. The cellular CDMA navigation solution is compared to the solution obtained from the UAV's on-board navigation system (the A3 flight controller), which consists of a GPS receiver, an IMU, a barometer, and a magnetometer.

  UAV Navigating with Cellular CDMA Signals

 

GPS Vertical Dilution of Precision Reduction using Signals of Opportunity

This video presents simulated and experimental demonstrations of exploiting signals of opportunity (SOPs), e.g., cellular signals, to reduce the relatively large vertical errors that are intrinsic to a GPS-only navigation solution. Since cellular signals are transmitted from towers located in favorable geometric configurations, fusing them with GPS signals significantly improves the accuracy when compared to a GPS-only navigation solution.