Development and test of a frequency hopped waveform for Medium Data rates

This paper describes the design of a slow frequency hopping waveform for Satcom medium data rates. The operating mode to enter the network and to maintain the orthogonal frequency hopping with a long loop is essential in the system to establish a traffic link and is described accurately. Then the main characteristics of the traffic waveform are given and the performances are evaluated by simulation on a Gaussian channel and with PBNJ (partial band noise jamming). The worst case jamming is obtained for a partial band close to 1. In order to validate some critical points, a breadboard was developed by the French contractor THALES implementing the 2 data rates 64 and 256 Kbps. The CELAR (Centre d´Electronique de l´Armement) evaluated the performances through a satellite transponder simulator in linear and limited modes and with different kinds of jammers. The tests showed good performances and robustness of the synchronization network and the traffic links. Finally traffic links were established through the TELECOM 2A satellite in order to validate the concept of orthogonal hopping in real conditions with a real satellite transponder