Transmission of Video with Convolutional Coding in Cooperative Ad Hoc Networks

In wireless networks, the value of cooperative communication cannot be over stated. It has attracted a lot of attention because of its capacity to successfully address the problem of fading in wireless communication. With the use of relays between source and destination, the quality of information received at the destination improves dramatically. The problem addressed here is that when video is sent straight from source to destination on an ad hoc network, the quality is poor. Video quality can be improved by adding a relay node between the source and destination, which uses a decode and forward approach before sending the data to the destination. To combine the signal received from the source and the relay, maximum ratio combining (MRC) is used at the destination. This is the concept of cooperative communication. In the presence of additive white Gaussian noise (AWGN), video is conveyed using BPSK/QPSK modulation technique over a Rayleigh fading channel in 802.11b wireless ad hoc network. The video quality is analyzed in terms of Peak signal to noise ratio, latency and bit error rate in the presence of convolutional coding as well as in the absence of convolutional coding. The results indicated that measured video quality with relay was considerably better than the measured video quality without relay, emphasizing the necessity of cooperative communication.