Biography
Enrollment Date: 2012
Graduation Date：2015
Degree：M.S.
Defense Date：2015.06.03
Advisors：Liji Wu Hanjun Jiang
Department：Institute of Microelectronics，Tsinghua University
Title of Dissertation/Thesis：Design and Implementation of Wireless Communication IP Cores for Tire Pressure Monitoring System
Abstract:
With the development of automobile technology, traffic safety has become increasingly demanding, so Tire Pressure Monitoring System（TPMS）is becoming an essential safety system in cars. US, European and ISO have issued different TPMS standards. China’s national recommended TPMS standard was issued in 2011. Wireless communication is a key part in TPMS, the proposed wireless communication scheme for TPMS consists of two parts: the 125 KHz low frequency wake-up communication link for system low-power, and the 433 MHz data transmission link for the transmission and reception of status data, such as tire pressure, temperature, etc. Both the above-mentioned low frequency wake-up communication link and the data transmission link include a receiver and transmitter circuitry. In this paper, the design and implementation of 125 KHz low frequency wake-up receiver and 433 MHz data transmitter is completed, along with the front-end design and part of layout of 433 MHz data receiver. The 125 KHz low frequency wake-up receiver is used to reduce the power consumption of tire monitoring module in TPMS, and the 125 KHz low frequency wake-up transmitter sends wake-up signal to achieve proactive monitoring to reduce system power consumption. The design of 125 KHz low frequency wake-up receiver adopts low noise, low mismatch and sub-threshold methods, while using dual-channel communication to improve the reliability of communication and logarithmic amplifiers to achieve ASK demodulation and dynamic range compression to reduce power consumption of the receiver. The receiver is taped out in ASMC 0.35μm automotive electronics process. Post layout simulation result shows that the overall working current is 5μA.After up conversion, the 433 MHz data transmitter transmits the temperature, pressure and other data acquired by tire monitoring module, with ASK modulation. The transmitter mainly includes PLL, power amplifier, ASK modulator and power management. The transmitter was taped out in UMC 0.18μm 1P6M MMRF process. Test result shows some performance improvement in transmitter power, PLL lock time, and phase noise. The optimized typical power consumption of the transmitter is 7.3mA, reducing 2.7mA; reduced PLL lock time from 134μs to 43μs, phase noise increases from -100dBc @ 300 KHz to -110dBc @ 300 KHz. The 433 MHz data receiver receives the data transmitted by the 433 MHz data transmitter. After down conversion, it performs ASK demodulation and then transmits the data to the cab control module inside automobile. The receiver consists mainly of low-noise amplifier, mixer, IF filter, IF amplifier, peak detector and comparator modules. The front-end design of the module has been completed, and the layout design of the module is partly done.