NTM88: RF packets missing at receiver end when the sensor is installed on the wheel and rotating

[ankit2631]

I am using NTM88 dual axis sensor for TPMS application,NTM88 is being used as transmitter and NCK2910 EVK as receiver. I have installed the sensor on Wheel rim of a vehicle and distance between sensor and receiver is 14ft to 16ft, output power of sensor is 8dBm . RF data packets are received properly at the receivers end when sensor is stationary or wheel is not rotating, but as soon as i start rotating the wheel above @20Kmph packets start missing or corrupted.

Is there a way to avoid or minimize the missing packets?

[TomasVaverka · Accepted solution]

Hello Ankit,

The following strategies can be used to improve the reception rate:

• RF configuration: make sure that RF settings on the NTM88 side match the receiver settings (same carrier frequency, deviation, baud rate…).
• Enable multiple frame transmission randomization on the NTM88 side. This feature allows to transmit the same frame multiple times, with a random delay between them. Doing so allows to increase the reception rate. On the other hand, it increases the power consumption. So, a trade-off is to be found between the number of transmissions and power consumption. Refer to the “Transmission Randomization” section of the NTM88 user manual: https://www.nxp.com/webapp/Download?colCode=UM11227&appType=license

• Optimize the antenna design and matching network on the NTM88 PCB. Make sure that the impedance at the NTM88 RF pin is as close as possible as indicated in the file “TPMS_Impedances_for_matching_network” located in the documentation folder of the Starter Package: https://www.nxp.com/webapp/Download?colCode=NTM88-NCK2910-STARTER-PACKAGE

BR, Tomas

[ankit2631]

Hello Tomas,
Thanks for the reply, can i also use angle location algorithm? will sending the packet at a particular angle reduce the packet losses?

[TomasVaverka]

Hello Ankit,

Yes, sending the packet at a particular angle may reduce the packet losses. Depending on the position of the receiver in the car, there may be a transmission path that would optimize the reception rate.

However, running the angle location algorithm consumes power. So, it is necessary to compare the consumption and reception rate of both solutions (using transmission randomization and using angle location) to determine which one is most appropriate.

BR, Tomas