System performance of EDGE, a proposal for enhanced data rates in existing digital cellular systems

The use of alternative modulation to provide Enhanced Data rates for Global Evolution (EDGE) is currently being standardized for GSM by the European Telecommunications Standards Institute (ETSI), and is also adopted for IS-136 evolution by the Universal Wireless Communications Consortium (UWCC) in the US. This paper analyzes the system performance of the EDGE concept. Two scenarios are studied: one where EDGE is introduced in an existing GSM system with 3/9 frequency reuse, and one where EDGE is introduced as an IS-136 overlay, using a very limited amount of spectrum and 1/3 frequency reuse. Both capacity and coverage results are provided. Simulations show that the introduction of EDGE significantly increases the user bit rates in both coverage and interference limited systems compared to standard GSM. The spectral efficiency is also increased considerably. It is also shown that spectral efficiencies exceeding 0.45 bps/Hz/site can be achieved when EDGE is introduced in an IS-136 system using a 1/3 frequency reuse pattern. Further, coverage simulations indicate that existing sites can be reused when EDGE is introduced.