(Diploma Thesis, 2008 - 2009)
|(a) Infineon SP35 TPMS.||(b) LF-receiver architecture.||(c) Bit-error-rate for various nonlinear 1 bit filters.|
Correct pressure in car tires avoids accidents and reduces CO2 emissions. Hence the US government enacted the so called TREAD act in 2000. This act determines that in every new car produced after 2006 a tire pressure monitoring system (TPMS) has to be included. The Infineon SP3x chips series measures the pressure and temperature in the tires. Because of energy saving reasons these chips are in idle mode until they are woken by an external controller. This wakeup signals are Manchester encoded data messages which are sent with an on-off-keying modulation scheme at a carrier frequency of 125kHz. The aim of this project was to enhance the performance of the digital LF receiver architecture with low-power and low-complexity techniques, and to illustrate the functionality and the models of the air interface, the analog front end, and the digital baseband processor of the LF receiver. The bit error rate (BER) and the message success rate (MSR) of the original receiver were evaluated. Various 1bit filters were proposed which are able to increase the performance of the receiver. Additionally a new chip detector and a new Manchester decoder were introduced. These modifications demonstrated a significantly better BER and MSR performance than the original receiver. The different architectures were compared with respect to their BER, MSR, and their complexity in contrast to the original receiver.
Funding: Infineon Austria AG.
Project Partners: Graz University of Technology, Infineon Austria AG.
- A. Pedroß, "Modeling and Simulation of an LF-Receiver," Diploma thesis, Graz University of Technology, Graz, Austria, June 2009, (conducted in cooperation with Infineon Technologies Austria AG, Austria).