Performance Analysis Of Multicast Multi-hop Relay Network

The demand of high data-rate applications over wireless network paves a way to the multi-hop wireless communication by incorporating relays. The relay nodes not only help to improve the capacity but also beneficial for range extension. Fortunately the densely populated independent single antenna nodes can act as a virtual antenna array by exploiting the broadcast nature of wireless medium. A number of cooperative communication protocols have been presented in recent years like amplify-and-forward, decode-and-forward, detection and forward and compress-and-forward. To the best of our knowledge there is no research found to evaluate multicast performance of dual hop relay networks. In future cellular networks, the proposed multicast scheme not only helpful for real-time applications but also helpful to increase the throughput for an end user.In this research, we explore a multicast based amplify and forward relay over multi-hop networks using dual relays. Unlike cooperative communication, there is no direct signal between transmitter and pair of intended receivers; instead another relay contributes to increase the throughput. There are two possibilities that the intermediate relays cooperate with each other or Amplify and forward the signals. In low energy regime, the multicast scheme will be more beneficial. If the nodes are densely populated then the relay nodes can behave as virtual MIMO and if the distance between the nodes is higher than a certain threshold then they need the cooperation between each other at the cost of an extra time-slot. However the later one, co-operative multicast scheme, can achieve a 4 dB gain over virtual MIMO. The Channel coding can further enhance the performance of the multicast scheme. In order to remove the complexity of the relay nodes, we have incorporated the channel coding at the transmitting node and decoding at the receiving nodes. It means that the relay nodes become transparent to the protocol used at the relay nodes. The performance of the above scheme has been evaluated for both the cases of diversity and multiplexing.Furthermore, we proposed the joint network and channel coding based for the two way multicasting. The network coding helps to make the two-way communication in two time slots. For the uplink we make an assumption that the multiple mobile stations intend to transmit the same information to the BTS, as in multicasting we usually transmit the same information from one point to another point.OFDM is the wireless DSL and as the DSL is the broadband wire line technology OFDM is the wireless broadband technology. Finally we use the OFDM to make a better multicast scheme for real-time applications over the cellular networks. For dual hop, we need the sub-carrier coupling. To achieve the better end-to-end SNR, the sub-carrier mapping (SCM) scheme can be used. In SCM the best received SNR sub-carrier mapped into the best received SNR sub-carrier, second best received SNR sub-carrier mapped into the second best received SNR sub-carrier and so on. The Symbol Error Rate is derived for the OFDM based SCM for the proposed multicast scheme at the end of this research work.