New Criteria and Related Techniques for 4G Wireless Systems

Summary form only given: 3G technologies have been widely deployed in Europe, Japan and other countries since 2000. But few 3G telecom operators could claim profitable from the current services provided by 3G networks. The real issues hit the 3G flying are spectrum efficiency, uplink bandwidth and overall cost with CDMA based technology. This presentation, based on SCDMA, TD-SCDMA, and McWill deploying experiences in the last ten years in China, proposes new criteria for 4G wireless communication systems. Under the proposed criteria, what are missing in current wireless communication theory is addressed. In order to increase the spectrum efficiency and uplink bandwidth in a 4G system, the presentation gives a way to optimally consider frequency, time, spatial, and coding domains issues altogether. Most importantly, the presentation points out new foundation based on multi-user information theory for wireless communications, which might be one of many means that can effectively increase spectrum utilization. Uplink bandwidth is a bottleneck for many wireless communication systems. Traditionally, in order to get higher bandwidth efficiency, a higher order or multi-level modulation (such as QAM 64) should be normally adopted, which requires high output power in subscriber terminal side. This talk shows an alternative way to handle high bit/symbol rate modulation without high multi-level output power.