Multihopping for OFDM based Wireless Networks

The goal of this report is to show how the multicarrier character of OFDM based wireless networks can be exploited when implementing multihopping. When it is not possible to establish a connection between a base station and a wireless terminal or when this connection is not of a satisfactory quality, multihopping can be used. In this report it is shown that with only a few multihopping nodes the connection quality with far away nodes can be drastically increased using subcarrier scheduling, based on the information of the quality of individual subcarriers. [3] First a binary model is used to show the results of this kind of multihopping. It is compared with the conventional case where the total signal follows the same path. It is assumed that the signals make 2 hops before arriving at the receiver. So there is one level of multihopping nodes. Further more it is assumed that the only degradation of the signal occurs between the sender and the intermediate nodes and not between the intermediate nodes and the receiver. This is done for simplification of the model. Secondly a M-ary model is used to see the impact of a more realistic channel model. And finally a M-ary Gaussian channel model is considered.