Improving the capacity of wireless networks using physical layer network coding

Abstract

The rapid demand for data rate due to the vast increase in mobile users and their desire for real time data services like video streaming, online gaming and social networking urge the wireless researchers to develop innovative communication strategies for improved resource utilization. We have proposed technologies to exploit the channel characteristics such as superposition and natural linear computation properties and also we have introduced data compression techniques at the source node exploiting the statistical properties of the information source. Wireless channel is broadcast in nature and information transmitted by a node is heard by all the destination nodes which are within source node s vicinity. Except for the intended destination, for all the other nodes, the received information is nuisance or interference. To eradicate this nuisance, orthogonal resources are used between the nodes to avoid collision of one user s signal with other. Physical layer Network Coding (PNC) is a new signal processing technique which exploits this broadcast nature of the wireless channel and turn that into capacity boosting property. Two Way Relay Network (TWRN) consists of two sources (and#1845;1and and#1845;2 ) capable of half duplex transmission, exchanging their information via a single relay node . PNC principle is based on the key idea of Network coding in which the intermediate relay nodes in the network transmits the coded information instead of simply forwarding the received data, thus achieving best possible network throughput. In time slot 1, the two sources are transmitting their packets to relay node R and this phase is called Multiple Access Channel (MAC) phase. newline