Biography

Enrollment Date: 2009

Graduation Date：2012

Degree：M.S.

Defense Date：2012.05.24

Advisors：Chun Zhang

Department：Institute of Microelectronics，Tsinghua University

Title of Dissertation/Thesis：Design of 2.4G Transceiver baseband Circuit

Abstract:
This paper analyzes the application requirement of RFID, working in 2.4GHz frequency band UHF RFID chips have larger application prospect. RFID chips with work in 2.4GHz frequency band are usually active tags. The tag and reader chip structure basic symmetry, it modulation are usually phase modulation technology. Digital modulation and demodulation technology and circuit implementation is very important for 2.4GHz UHF RFID chips. This paper had completed the 2.4G RFID baseband circuit design and implementation based on the standard of IEEE802.15.4. And by using Xilinx System Generator tools implemented the high-level validation. Firstly, this article has analyzed the standard IEEE802.15.4, and improved it for RFID application. The direct sequence spread spectrum technology has been used to improve the communication performance, modulation mode are support O-QPSK and DBPSK two patterns. Digital transmit and receive all using I/Q structure, so the transmitter algorithm must be applied to the orthogonal structure, it can support O-QPSK and DBPSK two modulation modes. The receiver uses the coherent quadrature demodulation method. For digital baseband signal processing, this paper uses differential demodulation mode, eliminates the phase offset influence, and the frequency offset is converted to a phase shift. In the Gauss channel simulation environment, analysis the demodulation algorithm, meet the protocol on the communication quality requirements, the BER of 0.1%@-1.5dB. Design of the digital baseband circuit include of digital receiver and transmitter circuit, and integrated evatronix company's 8bit single cycle instruction microprocessor IP core R8051XC2, using UMC0.18um chip implementation process. Digital transmitter includes FIFO, transmit state machine, spread spectrum coding, digital modulation and shaping module five parts, the general framework, which can support O-QPSK and DBPSK two modulation methods. Digital receiver comprises conjugate differential, a sliding correlator, serial correlation dispreading, receive state machine controller and cached FIFO five modules. Since there is no complex computation and feedback loop, receiving circuit stability. According to the design of the transmitter and receiver circuit structure, in the MATLAB environment using System Generator tools to achieve a high level synthesis, and in the FPGA verification platform to realize wireless communication test.

Publications

Papers：：

[1] Lu Li,Chun Zhang,Caifeng Wei,Pan Wu,Zhihua Wang, A Reconfigurable Wireless Digital Phase Modulator and Demodulator, ICEICE 2012, pp. 97 - 100, 2012.

[2] Lu Liu,Zhihua Wang,Guolin Li, The Application of Volterra Series in Linearity Analysis of High Frequency CMOS Transconductance, Research & Progress of Solid State Electronics, Vol.26, No.4, pp. 490 - 493, 2006.

[3] Lu Liu,Zhihua Wang, Analysis and design of a low-voltage RF CMOS mixer, IEEE Transactions on Circuits and Systems II-Express Briefs, Vol.53, No.3, pp. 212 - 216, 2006.

[4] Lu Liu,Zhihua Wang, Microelectronics, Vol.35, No.6, pp.1, 2005.

[5] Lu Liu,Zhihua Wang, A new high gain low voltage 1.45 GHz CMOS mixer, ISCAS 2005, pp. 5023 - 5026, 2005.

[6] Lu Liu,Zhihua Wang,Guolin Li, Calculation of intermodulation distortion in CMOS transconductance stage, ISCAS 2005, pp. 3700 - 3703, 2005.

[7] Xiang Xie,Guolin Li,Xinkai Chen,Lu Liu,Chun Zhang,Zhihua Wang, A Low Power Digital IC Design Inside the Wireless Endoscopy Capsule, A-SSCC 2005, pp. 217 - 220, 2005.

[8] Ziqiang Wang,Baoyong Chi,Min Lin,Shuguang Han,Lu Liu,JinKeYao,Zhihua Wang, A monolithic CMOS L band DAB receiver, ASP-DAC 2005, pp. 1232 - 1235, 2005.