ABSTRACT
This chapter examines the performance of digital transmission over a fading environment. It reviews the bit error rate of some binary modulation schemes, namely, frequency-shift keying and phase-shift keying. The chapter outlines how their performance can be improved. It discusses the occurrence of errors in data transmission of the mobile radio system as well as investigating the usual methods employed to minimize error occurrence. The chapter analyzes the Viterbi algorithm initially implemented in a software form using a computer and more recently, implemented in VLSI chips. Data transmission, generally, can tolerate delays and bit errors, whereas signalling usually requires quick response and a very low error rate. In a mobile radio'system, data or control signalling can be transmitted over speech channels or separate signalling channels, depending on the control task to be performed. Data and control signalling involve digital transmission but with different requirements.
