Implementation of a rate control algorithm for compressed sensed videos on a software defined radio.

摘要

Wireless Multimedia Sensor Networks (WMSNs) applications are multifaced. However, a key area of audio and video transmissions over a WMSN remains unexplored. Conventional video encoding techniques have high encoder complexity and low resiliency to channel errors. Network fairness and congestion also need to be addressed.;In this work, a low complexity video encoder based on compressed sensing, and a rate controller for video streaming over wireless networks are implemented. This algorithm jointly regulates source and channel encoding rates.;Compressed sensing (CS) is a tool to find a sparse solution for underdetermined linear systems. This allows sampling at sub-Nyquist rates and still enables recovery based on convex optimization techniques. This helps reduce the amount of data generated at the sources. Channel coding is based on a novel adaptive parity scheme that varies the strength of channel coding based on the current estimated bit error rate of the channel.;The algorithm is implemented on an USRP2 Software Defined Radio (SDRs) considering the benefits it offers in terms of flexibility. It I tested in a real multihop OFDM network. Results show that the rate control algorithm converges under congested and uncongested network conditions. The algorithm also recovers under side traffic conditions.