Xueting Liu

3175 S. Sepulveda Blvd. #304 

Los Angeles, CA 90034   

Email: liu_xueting@yahoo.com

Mobile: (310) 866 – 7289

OBJECTIVE:

Seeking a communication systems engineer position in the fields of communications systems and digital signal processing.  Several key qualifications are summarized below:

• Strong background in digital communication theories, industry specifications and implementations, e.g. GSM transmitter and receiver, V.17 modem, ITU - T I.363.2 ATM/AAL2 network receiver, etc.
• PhD thesis on trellis codes design and adaptive coded modulations for time-varying channels.
• Highly experienced with DSP algorithm and implementations, e.g. channel estimation, MLSE equalizer with SOVA, Viterbi decoding, code-excited linear prediction (CELP), codebook search using MMSE criterion, jitter buffer design, fix-point math, etc.
• Expertise in high level programming language such as C, Matlab.

PROFESSIONAL EXPERIENCES:

University of California, Los Angeles, Optimization and Communication Laboratory

Los Angeles, California

Postdoctoral Scholar                                                                                                                                           

2003 – Present

Working as a postdoctoral scholar in Professor Rick Wesel’s research group. My work is focused on:

• Investigated the effect of the accuracy of the past channel fading estimation on the performance of our new low latency adaptive coded modulation.

• Designed and implemented the GSM transmitter and receiver. The GSM transmitter includes block coder, convolutional coder, interleaving, burst building, GMSK modulation and Jakes' modeling of multipath fading channel. The GSM receiver includes channel estimation using sliding window approach, Ungerboeck's MLSE equalizer with soft-decision outputs (SOVA) and channel decoder with soft-decision inputs.

• Working on algorithms of single antenna interference cancellation (SAIC) for GSM on GMSK/8PSK modulation.

GlobespanVirata, Inc.

Santa Clara, California

DSP Engineer                                                                                                                                                     

2000 – 2002

Served as a member of a 6 people DSP group, I was responsible for the design, implement and test of various DSP modules for the Globespan Voice over Packet (VOP) solution. Main projects included ITU-T G.729A CS ACELP Voice Codec, DTMF detection and V.17 fax modem. I also participated in the integration of the high density Central Office (CO) VOP chip-set and the Customer Premise Equipment (CPE) VOP chip-set.  Main tasks included network error detection (CRC/checksum), full reassembly of AAL2 packets and the design of adaptive jitter buffer to combat buffer overflow.  The key accomplishment:

• Successfully implemented ITU-T G.729A CS ACELP codec and made it meet the real-time constraint of our high-density voice processor.

• Within a time frame of 2 weeks, successfully simulated, implemented and finally optimized a DTMF algorithm to meet the real-time constraint of our high-density system.

• Participated in chip architecture specification to improve the performance of our system.
• Designed and implemented ATM/AAL2 network receiver ITU-T I.363.2, including CRC checking, full reassembly of AAL2 packets, network error handling and the design of an adaptive jitter buffer.
• Designed and implemented a fax-relay V.17 modem, requiring digital sampling and filtering, Hilbert transform, trellis coded modulation to adaptive to different transmit data rates and Viterbi decoding.

University of California, Los Angeles, Optimization and Communication Laboratory

Los Angeles, California

Graduate Research Assistant                                                                                                                             

1997 – 2000

As a graduate student, my ph.d thesis was on trellis codes design and adaptive coded modulations for time-varying channels. My research was focused on:

• Designed a universal trellis code for periodic erasure channels, reducing a multi-criterion optimization problem to a maximization of indicated objective functions.
• Investigated constellation-labeling paradigms for cross constellations to achieve better performance for trellis codes over channels with fading or puncturing and trellis turbo codes.

• Analyzed robustness of non-regular trellis codes and bit-interleaved codes to channel prediction errors by using the transfer function bound.
• Designed bandwidth efficient, low latency adaptive coded modulation schemes for time-varying channels, achieving better performance for systems with highly mobile users requiring low-latency.

EDUCATION:

Ph.D. in Electrical Engineering, major in communications and telecommunications

University of California, Los Angeles

1996–2000     

     Doctoral Thesis: Trellis Codes Design for Periodic Erasures and Adaptive Coded Modulation

                                 Schemes for Time-Varying Channels

     Advisor: Professor Richard D. Wesel

     Master of Science, Electrical Engineering                                                                                                  

1992 – 1995

Institute of Automation, Chinese Academy of Sciences

Bachelor of Science, Electrical Engineering                                                                                                 

1988 – 1992

Central South University of Technology

SKILLS:

• Expertise in error correction coding and link adaptation.
• Familiarity with ATM/AAL2 and TCP/IP network protocols.
• In-depth understanding of OFDM/DMT and CDMA techniques (rake receivers, diversity techniques).
• Expertise in use of C from high-level to bit-exact, fixed-point operations, Matlab and Assembly language.
• Frequent user of Unix, Windows, MS-DOS and Sun workstations.

WORK STATUS:

      I am a permanent resident of USA and authorized to work in this country for any employer.

AWARDS:

• EE department fellowship recipient at University of California, Los Angeles.                                              1996 – 1997
• Excellent student award at Institute of Automation, Chinese Academy of Sciences.                                    1993
• Fellowship recipient at Central South University of Technology.                                                                 1988 – 1992

JOURNAL PUBLICATIONS:

• X. Liu, P. Ormeci, R. D. Wesel and D. L. Goeckel, "Low Latency Adaptive Coded Modulation Based on an Estimate of the Received Bit error Rate”, accepted under revisions to IEEE Transactions on Communications, 2003.

• A. Bernard, X. Liu, R. D. Wesel and A. Alwan, "Speech Transmission Using Rate-Compatible Trellis Codes and Embedded Source Coding", IEEE Transactions on Communications, Vol. 50, No. 2, Feb.  2002.
• R. D. Wesel, X. Liu, J. M. Cioffi and C. Komninakis, “Constellation Labeling for Linear Encoders", IEEE Transactions on Information Theory, Vol. 47, No. 6, Sept. 2001.
• P. Ormeci, X. Liu, D. L. Goeckel and R. D. Wesel, "Adaptive Bit-Interleaved Coded Modulation", IEEE Transactions on Communications, Vol. 49, No. 9, Sept. 2001.
• R. D. Wesel, X. Liu and W. Shi, “Trellis Codes for Periodic Erasures”, IEEE Transactions on Communications, Vol. 48, No. 6, June 2000.