Lossy transmission of a Gaussian source over an additive white Gaussian (AWGN)
channel with side information at the decoder is tackled under the regime of
bandwidth expansion. A previously known scheme, hybrid digital/analog
Wyner-Ziv (HDA-WZ) coding is shown to remain optimal when extended from the
bandwidth matched case to the bandwidth expansion case. The extended scheme also
exhibits similar robustness properties under mismatched side information and/or
channel quality. Its robustness is compared against a purely-digital scheme
known as common description scheme (CDS) and uncoded transmission under the
criterion of min-max distortion loss introduced in this paper.