ABSTRACT

This chapter addresses the basic carrier synchronization system design and presents results. It provides field measurements that will serve to demonstrate the improvements in reception quality, both static and mobile, in the region of overlapping fringe-area co-channel contours that can be realized with transmitter carrier synchronization techniques. The chapter discusses the long-term successful implementation and operation of two local-area synchronous amplitude modulated (AM) station networks utilizing multiple co-channel boosters. The interference patterning in the synchronous overlap zone can be further reduced by phase-dithering of the booster signal(s), either in a cyclic or random-phase fashion. The concept of AM co-channel Global Positioning System based synchronous boosters to augment the coverage of existing AM stations is not new in the US broadcast market. The synchronous AM system, once set up, is very stable and generally won't need readjustment unless there is an equipment change or failure.