On the SNR exponent of hybrid digital-analog space time coding Conference Paper uri icon


  • We consider the transmission of a real i.i.d. "analog" source over a quasi-static M-input N-output MIMO fading channel. The relevant performance criterion is end-to-end average quadratic distortion D versus channel SNR, for given spectral efficiency ν, defined as the ratio of the source bandwidth over the channel bandwidth. We define the distortion SNR exponent a ∗( ν) as the largest a = -limsnr→1 logD/ log snr, over all possible source-channel coding schemes. We find a closed form upperbound on a ∗(ν), a lower bound asep(ν) achievable by separated (tandem) source-channel coding, and a tighter lower bound ahybrid(ν) achievable by hybrid digital analog space-time coding. In particular, we completely determine a ∗( ν) for the scalar fading channel and for the case ν ≥ 2M, for any M, N ≥ M. Explicit and simple constructions of hybrid space-time codes achieving ahybrid(ν) are also given.

author list (cited authors)

  • Caire, G., & Narayanan, K.

publication date

  • January 2005