Interdisciplinary Extensions

Publications, patents and artefacts:
- Invited Paper “Highly Parallel Decoding of Space-Time Codes on Graphics Processing Units”, Bollapalli, Wu, Gulati, Khatri, Calderbank. Annual Allerton Conference on Communication, Control and Computing, 2009, Urbana, IL. Sept 30 – Oct 2, 2009. In this paper, we implement the decoding tasks of a WiMAX base station on a GPU. We show that the GPU implementation is about 700X faster than a serial implementation. The results are significant, since they could dramatically reduce the cost of electronics in the base station.
- “A SAT-based Scheme to Determine Optimal Fix-free Codes”, Abedini, Khatri, Savari. Data Compression Conference (DCC), Snowbird, UT, Mar 24-26, 2010. Best student paper award. In this paper, we develop SAT based techniques to develop optimal fix-free codes. By expressing the code constraints as SAT formulae, and an efficient SAT solver is employed to find the codes.
- “High-throughput VLSI Implementations of Iterative Decoders and Related Code Construction Problems”. Nagarajan, Laendner, Jayakumar, Milenkovic, Khatri. Springer Journal of VLSI Signal Processing, vol 49, number 1, Oct 2007, pp 185-206. A shorter version of this paper appeared, in GlobeComm 2004, pp. 361-365. This effort reports the results of a custom-IC implementation of an LDPC decoder. The approach reduces routing congestion by careful code construction, and improves over standard cell based implementations in terms of power, delay as well as area.
- “VLSI Implementation of a Staggered Sphere Decoder Design for MIMO Detection”, Bhagawat, Ekambavanan, Das, Choi, Khatri. 45th Annual Allerton Conference on Communication, Control and Computing, Sept 26-28, 2007, Urbana, IL, pp. 228-235. A custom IC implementation of a sphere decoder is undertaken in this paper. Compared to existing approaches, our approach achieves significantly better throughput per unit power or throughput per unit area.
- “A Boolean Satisfiability based Solution to the Routing and Wavelength Assignment Problem in Optical Telecommunication Networks”, Valavi, Saluja, Khatri. International Conference on Communications (ICC), May 16 – 20 2005, Seoul, pp. 1802-1806. We cast the RWA problem as a SAT instance, and test it on networks with and without wavelength translation capabilities at the nodes. Results are 3-4 orders of magnitude faster than existing approaches.
- “Efficient Arithmetic Sum-of-Product (SOP) Based Multiple Constant Multiplication (MCM) for FFT”, Karkala, Wanstrath, Lacour, Khatri. International Conference on Computer-Aided Design (ICCAD) 2010, San Jose, CA. pp.735~738. This paper utilizes a SOP based approach to design a MCM circuit. The partial products are reduced using a partial Max-SAT formulation by exploring MSD based alternatives to realize coefficients. The area and delay results are significantly better than the adder-cascade based existing approaches
- “Practical & Real Time IP Routing Table Compression – Extending algorithms from digital logic synthesis”. Bollapalli, Khatri. Published by LAP Lambert Academic Publishing, Jan 2012, pp 68. ISBN 978-3847321521. This book reports our work on using efficient logic approaches to perform on-the-fly routing table compression for IP networks.
- “A Fast Ternary CAM Design for IP Networking Applications”, Gamache, Pfeffer, Khatri. 12th International Conference on Computer Communications and Networks (IC3N-03), Dallas, TX, October 2003, pp. 434-439. Selected among the finalists for the best paper award at the conference. In this paper, we design a ternary CAM IC, based on a very fast, pipelined longest prefix match circuit. The resulting IC operates at twice the line rate as compared to the best TCAM IC available at the time of publication.
- “A Generic Radar Processor Design Using Software Defined Radio”, Brimeyer, Martin, Loew, Farquharson, Khatri, Paul. 33rd American Meteorology Society (AMS) Conference on Radar Meteorology, Aug 6-10, 2007, Cairns, Australia. In this paper, we present a highly configurable, power-efficient radar signal processor for weather applications.
- “FPGA Based Signal Processing Platform For Weather Radar”, Paul, Khatri, Martin, Brimeyer, Loew, Vivekanandan. International Geoscience and Remote Sensing Symposium (IGARSS) 2007, July 23-27, Barcelona, Spain. This paper reports the results from an FPGA based implementation of a weather radar processor that we conducted. This processor was driven by a PCI interface, and was verified to operate correctly.