RCPT based Distributed Video Coding over IEEE 802.11g WLANs: The Role of the Puncturing Period on the System's Operation

In this paper, the role of the puncturing period on the operation of rate compatible punctured turbo (RCPT) code based distributed video coding systems is studied in the context of transmission over IEEE 802.11g Wireless Local Area Networks. Reasonably realistic network conditions are considered, with the impact of the Medium Access Control layer retransmissions taken into account. The effect of the puncturing period under such conditions is evaluated by means of rate/distortion results, incurred overhead and cumulative delay. The maximum number of requests permitted is derived for various packet error rates and is shown to be independent of the content. Increasing the puncturing period facilitates a refinement of the codec’s rate/distortion performance at the cost of increased parity bit requests, which in turn lead to an increase in delays. A packet error rate of 10% with a puncturing period of 64 would only support 61 requests before delays build up.