ABSTRACT

This chapter discusses several real communications links in order to put some of the theory presented into real-world situations. The ionosphere is transparent to microwave signals and this is put to good effect in satellite communications. Direct broadcast by satellite (DBS) is common place today with many TV and radio channels available to us. In a satellite broadcast service, a ground station communicates with the orbiting satellite using microwave frequencies. Manchester coding is also known as two-level pulse position modulation (2-PPM) because the pulse can take on one of two positions within the frame. The first-generation mobile phone was analogue in form and was quickly replaced by the digital second-generation (2G) phone. 4G is the latest system to be launched. The Digital audio broadcasting (DAB) service in use in Europe and the United Kingdom uses a system known as punctured convolutional coding. DAB exists in an environment of multipath propagation.