System performance with higher level modulation in the GSM/EDGE radio access network

Abstract

The GSM/EDGE Radio Access Network (GERAN) is presently being evolved as a full complement to the 3G UMTS network. One part of this evolution is the introduction of efficient support of real-time packet data and alignment to the UNITS Core Network. Another part will introduce performance-enhancing features aimed at improving spectral efficiency, peak and average user-throughput and capacity. One such enhancement being considered is the use of Higher Level Modulations to enhance the user peak rate in the GERAN, in much the same way as the data rate for GPRS was enhanced with the 8PSK modulation in EDGE. By introducing new coding schemes based on QAM the maximum bit rate per time slot could be increased up to 88.8 kbit/s. This paper explains the GERAN concept and investigates possible system level gains, from both spectrum efficiency and perceived user quality perspective, with Higher Level Modulation in GERAN.