Analysis and realization of a physical CDD system
The Code Division Duplexing (CDD) system has been developed recently. It is based on using a Code Division Multiple Access (CDMA) scheme on a Time Division Duplexing (TDD) system; the code applied to the CDD system is not the Walsh code, but rather an advanced smart code. In the past, the CDMA scheme can only be used in a Frequency Division Duplexing (FDD) system for cellular operations. But with this smart code applied to CDMA scheme, the CDMA scheme can be used in a TDD system for cellular operations. The smart code together with the TDD system becomes a CDD system. This CDD system can improve the current interference-limited environment to a noise-limited environment. In reality, the smart code cannot eliminate the interference entirely. This paper will analyze the anticipated physical CDD system performance based on the characteristics of the smart code. The cross-correlation value between two codes in a smart code set does impact the overall error probability and the system capacity. The new calculation introduced in this paper can provide a better understanding of the performance of the CDD systems. Copyright (C) 2003 John Wiley Sons, Ltd.
system performance system capacity mobile radio environment mobile communication systems 3g systems 4g systems cdd system and tdd system interference reduction