On the Design of Downlinks for Satellite Commuication Systems Using TFM and Convolutional Codes: A Simulation Approach with TOPSIM III

The performance of a TFM scheme applied to a satellite downlink with an on-board regenerative repeater is evaluated by using a time domain simulation software package TOPSIM III. The TFM bit error rate in the presence of nonlinearities and adjacent channel interference is evaluated by means of semianalytic methods. The capabilities of convolutional codes for reducing the overall channel bit error rate are also investigated. Design guidelines are finally outlined for advanced satellite communication systems in which the joint use of nonconventional modulation schemes (like TFM) and of convolutional codes results in improved performance with respect to both bandwidth exploitation and system flexibility.