[CPCC] SEMINAR: Computational Complexity of Decoding OSTBCs 11/23 10 AM

[Ender Ayanoglu]

                             CPCC SEMINAR


   Computational Complexity of Decoding Orthogonal Space-Time Block Codes

                                    by

                              Ender Ayanoglu

                         November 23, 2009, Monday
                                  10 AM
                          2430 Engineering Hall
                            (Colloquium Room)

                                 ABSTRACT

Orthogonal Space-Time Block Codes (OSTBCs) have been around for more
than a decade. It is well-known that the orthogonality properties of
OSTBCs lead to their decoding on a symbol-by-symbol decoupled basis.
In the original OSTBC papers, a metric which provides this decoupling
is introduced. Furthermore, basic Maximum Likelihood techniques have
been employed by several authors to come up with a number of other
decoding metrics.  In this talk, we will quantify the computational
complexity of decoding OSTBCs. We will unify the approaches from the
literature and will show four equivalent metrics which have the same
computational complexity. We will compare these metrics with the one
in the original OSTBC papers and show that, with a slight change, they
become equivalent. Finally we will provide a version of the optimal
metric where the division operation is avoided and the computational
complexity is minimum. We will also discuss the computational complexity
of a number of OSTBC examples and calculate their computational
complexity. We will explain when the computational complexity is
substantially reduced.

                            SPEAKER'S BIOGRAPHY

Ender Ayanoglu the Ph.D. degree from Stanford University, Stanford, CA
in 1986, in electrical engineering.  He was with the Communications
Systems Research Laboratory of AT&T Bell Laboratories (Bell Labs,
Lucent Technologies after 1996) until 1999 and was with Cisco Systems
until 2002. Since 2002, he has been a Professor in the Department of
Electrical Engineering and Computer Science, the Henry Samueli School
of Engineering, University of California, Irvine where he is currently
the Director of the Center for Pervasive Communications and Computing
and holds the Conexant-Broadcom Endowed Chair. Dr. Ayanoglu is the
recipient of the IEEE Communications Society Stephen O. Rice Prize
Paper Award in 1995 and the IEEE Communications Society Best Tutorial
Paper Award in 1997. From 1993 until now, he has been an Editor of the
IEEE Transactions on Communications and from 2004 to 2008 served as
its Editor-in-Chief. He served on the Executive Committee of the IEEE
Communications Society Communication Theory Committee from 1990 until
2002, and from 1999 to 2002, was its Chair.