Discussion of spectrum efficiency and the factors that affect it

Spectrum efficiency has become an important topic in the wireless communications industry due to the constant search for more capacity. Yet, there is much confusion about how to assess spectrum efficiency, for various technologies and situations, particularly in conjunction with other objectives such as cost and quality. The author presents a unified approach for the assessment of spectrum efficiency (Erlangs/km/sup 2//MHz) and discusses the main factors that affect it. Fundamental gain factors are introduced in the expression for spectrum efficiency. Then some practical aspects of system design and choice of capacity enhancement techniques are considered.<>