Co-ordination channels for digital satellite news gathering (DSNG)

This paper presents, in Section 1, a new approach to realising co-ordinatio n channels for digital satellite news gathering (DSNG). The key element of the approach to the co-ordination channels is a direct-sequence spread-spec trum processing of the data to be transmitted which allows for the realizat ion of an in-band transmission of the co-ordination channel signals overlay ing the DSNG main channel, the part of the system which is responsible for the transmission of the audio/video signal on a point-to-point basis. The s ystem is analysed in theory, simulation, and measurement with respect to sy stem performance and degradation of the DSNG main channel. It shows superio r system performance combined with a maximum of operational simplicity whil e the degradation of the DSNG main channel remains affordably low. Section 2 describes the DVB-DSNG system for co-ordination channels which incorporat es many elements of the system presented in the first part but is modified in some details in order to increase system flexibility. One of these detai ls concerns the possibility to perform in-band transmission as well as tran smission in the roll-off frequency space of the DSNG main channel. In-band transmission has the advantage of great operational simplicity and is nearl y identical to the system presented in Section 1. What characterizes the tr ansmission in the roll-off frequency space is the fact that it is more robu st and DSNG main channel degradation is negligible, but this at the price o f decreased operational simplicity. Copyright (C) 2000 John Wiley & Sons, L td.