1x Advanced
The 1x Advanced program is developing technologies for the next step in the evolution of CDMA2000 1x, a proven 3G technology that is currently providing services to 472 million subscribers in over 275 networks in over 100 countries (as of January 2009). The primary goal of 1x Advanced is to maximize voice capacity. With enhancements in receiver implementation and some minor changes to the standard, 1x Advanced can quadruple the voice capacity of today’s commercial CDMA2000 1x systems, far exceeding the voice capacity of any other 3G and even 4G wireless technologies. One of the benefits is then that it would free up precious spectrum resource which can be utilized to provide more EVDO channels.
Capacity of 1x systems can be improved incrementally. Use of EVRC-B codec and forward link interference cancellation (both available today) can achieve up to 50% gain in voice capacity. This is done without cell site modem (CSM) upgrade. With reverse link interference cancellation in the base station (new CSM required) and receive diversity in the mobile station, the voice capacity can be further improved by approximately 75%. A new radio configuration in the standard, which includes frame early termination, reduced power control overhead, and smart blanking, provides an additional gain in voice capacity of up to 60%. Note that all these capacity gains are obtained without degrading the voice quality or the robustness of the system and the new radio configuration is fully backward compatible with existing ones.
