The LPWA network processor supports GPS reception, if the onboard network protocol firmware supports it.
GPS receiver operation is time multiplexed with the LTE modem, and GPS and QZSS position can be received while the LTE modem is in RRC Idle mode, power saving mode (PSM), or completely deactivated.
The application processor is the system master and responsible for starting and stopping the GPS receiver. GPS can be run standalone or concurrently with QZSS. The GPS and QZSS reception can be configured through the GNSS interface API.
Key features of the GPS receiver are as follows:
The following is a summary of GPS receiver performance parameters.
Condition | Value |
---|---|
Environment | Open sky |
Temperature | 25°C |
GPS sleep clock source | TCXO |
Note: Local and temporal conditions might lead to considerable variation in TTFF, positioning accuracy, 1PPS signal accuracy.
The figures in the following table assume the use of an external low-noise amplifier (LNA) with SAW filter.
Symbol | Description | Value | Unit |
---|---|---|---|
Sensitivity, cold | Acquisition sensitivity, cold start | -146.5 | dBm |
Sensitivity, hot | Acquisition sensitivity, hot start | -152.5 | dBm |
Sensitivity, tracking | Tracking sensitivity | -156.5 | dBm |
TTFF, cold | Time to first fix (TTFF), cold start | 30.5 | s |
TTFF, hot | TTFF, hot start | 1.3 | s |
TTFF, A-GPS | TTFF, A-GPS start | 1.3 | s |
Accuracy, 2D, periodic | Positioning accuracy (CEP50), periodic tracking1 | 3.4 | m |
Accuracy, 2D, periodic, A-GPS | Positioning accuracy (CEP50), periodic tracking1 with A-GPS2 | 3.1 | m |
Accuracy, 2D, continuous | Positioning accuracy (CEP50), continuous tracking | 2.0 | m |
Accuracy, 2D, continuous, A-GPS | Positioning accuracy (CEP50), continuous tracking with A-GPS2 | 1.8 | m |
1PPS accuracy | 1PPS signal accuracy, continuous tracking | ±35 | ns |