Real link of a high data rate OFDM modem: Description and performance

This paper deals with the design of an integrated system that is able to transmit data with high data rate and also high quality. However, the main feature is not the enhanced performance but the objective of providing a nearly permanent and reliable communication over time. In order to overcome the long term fading, a probe modem is simultaneously monitoring all the available channels and ranking them in terms of feasibility. A general manager named ALMA (Automatic Link MAnagement) detects when the current transmission is being degraded and in a transparent way to the user, decides when and how the channel change happens. To make this approach feasible, we have developed our own broadband transceiver that is able to transmit / receive simultaneous streams. In this paper we will describe the performance of the probe modem, the criteria and strategy for channel changing and the performance of the stable data modem.