Fixed Relay In The Radio Cell Performance Analysis And Simulation

As rapidly developing, nowadays our society depends deeply on information technology. Thus wireless communication technology achieved a great improvement on aspects such as communication quality, data rate and channel capacity. However, there's a strong desire for large amount of data transmitting, recently. Current wireless communication services are getting more and more difficult to satisfy the communication demands. Anyway, traditional communication technology is hardly improved, since the limits of bandwidth, signal attenuation while propagation, interferences and noises. To deal with all these limitation, several novel technologies are proposed last decade, among which Multi-Hop technology attracts more and more attentions, for it's a new technology that is able to increase the quality of communication.Multi-Hop completes a whole communication via the signal relaying using some nodes in the wireless cells. It is an on-going research and is carried out in phases. Phase 1 concerns peer-to-peer relaying. In this phase, the user-equipments can not only receive signals, but also relay the signals for other equipments. Phase 2 is about the fixed relays, fixed relays are located in certain positions of the cells for the purpose of relaying signals.This thesis introduces the infrastructure of a type of wireless-cell system with fixed relays, presenting its relaying channel partition scheme and several relay selection algorithms as well. Also the performances of the relay selection algorithms are qualitatively analyzed, and further more, an approach to simplify the algorithms is proposed. Then, simulation results are given out, which are used to prove that, different relay selection algorithms bring different performances, and illustrate the enhancement which the relay selection algorithms introduced in the system are apparently, comparing to the no relay cells. Meanwhile, through comparing the results of simplified algorithms' and the corresponding original algorithms', this thesis proves the fact that the simplified algorithms are more easily to realize with less signaling overheads, yet only a little bit inefficient than the original algorithms. At the end of this thesis, we draw the conclusions and suggest several future researches.