Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
High data rates and increased coverage area are the requirements of future wirel ess networks. Novel systems are looked into to support the needs. One among them are the Multihop systems. Multihop systems offer substantial power saving when compared with single hop networks. This means they can provide increased coverage area and at the same time support high speed data services.
One of the key elements of a multihop system is the relay. Relays are of two types, non regenerative and regenerative relays. Non regenerative relays are relays which amplify and relay the received signal, whereas, regenerative relays decode the received signal and re-encode it prior to re-transmission. In terms of hardware complexity, non regenerative relays are simple and regenerative relays are complex. A study on the performance analysis of these relays shows that regenerative relays perform better when compared with the non regenerative relays. At the same time, a simpler version of the regenerative relay, semi regenerative relay, is as good as the regenerative relay at high SNRs. The fact that it needs only a fraction of the complexity as that of the regenerative relay recommends the need to study more.
In this thesis, work has been carried out to simplify the regenerative relay terminal and measure the impact of simplification on the system performance. Three models are proposed for simplification. They are coded with hamming and BCH codes and their performance is analyzed in a multipath environment. The findings show that there is a loss in performance of the models due to simplification. The loss is more pronounced in the fast fading case. In the block fading case, the simplest and the complex model produce identical performance at high SNR's. When soft decision decoding is included the simplest and the complex model produce identical performance right from low SNRs.
2005. , 37 p.
Slimane, S. Ben