3G移动通信CDMA/TDMA改进方案

3G移动通信系统应该以提供移动Internet业务为主，将存在多个不同的速率，而如何实现多速率兼容是一个需要特别关注的问题。给出了多速率CDMA移动系统中不同速率信道发送功率与发信速率的关系式，将原有的计算式进行了推广，并由此导出一种CDMA/TDMA技术，该技术可用于改进原FDD WCDMA和CDMA2000标准中只使用CDMA和VSF实现多用户多速率兼容的方法。可以成倍增加系统下行容量并提高功率利用率，克服了CDMA2000 1x和WCDMA标准上下行容量基本对称的技术缺陷。

Ameliorated CDMA/TDMA scheme in 3G mobile communication

The third generation mobile communication system should be designed mainly to offer wireless Internet services. Consequently, there exist several different data rates in the 3G system and much attention is focused on the compatibility of multi-rate data of it. This paper presents the equations for the relation of transmission power and data rates in multi-rate CDMA system. Based on the theory, the authors further deduce a novel technique by combining CDMA mode with TDMA that can be used to improve the immaturity of the multi-user and multi-rate compatibility in former FDD WCDMA and CDMA2000 standards which only employ CDMA mode and VSF. The new method can significantly increase the system downlink capacity and enhance the power efficiency, so as to ameliorate the limitation of symmetric up/downlink capacities in CDMA2000 1x and WCDMA standards.