Sanket Dusad, Ph.D., 2008
Thesis director: Prof. S N. Diggavi
- Prof. E. Biglieri (Politechnico di Torino)
- Prof. A R. Calderbank (Princeton)
- Prof. R. Urbanke (EPFL)
- Prof. B. Rimoldi (EPFL, Committee president).
Sanket worked on “diversity embedded codes” for broadband wireless channels and developed both an algebraic framework as well as information-theoretic characterizations. Diversity embedded codes were invented to provide multiple levels of error protection for wireless channels. Space-time codes with this diversity-embedding property had been developed for narrowband channels. Sanket, in this thesis, developed a comprehensive theory and designed diversity embedded codes for broadband channels. The use of rank-distance codes led to a new algebraic construction of diversity embedded codes and these constructions may be also of independent interest. From an information theoretic viewpoint, it was shown, perhaps surprisingly, that the diversity-multiplexing trade-off for broadband (ISI) channels was successively refinable (for a single degree of freedom), and therefore this led to optimal code designs for broadband (ISI) channels.