ParCast: Soft video delivery in MIMO-OFDM WLANs

Abstract

We observe two trends, growing wireless capability at the physical layer powered by MIMO-OFDM, and growing video traffic as the dominant application traffic. Both the source and MIMO-OFDMchannel components exhibit non-uniform energy distribution. This motivates us to leverage the source data redundancy at the channel to achieve high video re- covery performance. We propose ParCast that first sepa- rates the source and channel into independent components, matches the more important source components with higher- gain channel components, allocates power weights with joint consideration to the source and the channel, and uses analog modulation for transmission. Such a scheme achieves fine- grained unequal error protection across source components. We implemented ParCast in Matlab and on Sora. Extensive evaluation shows that our scheme outperforms competitive schemes by notable margins, sometimes up to 5 dB in PSNR for challenging scenarios. Copyright © 2012 ACM.