WCDMA – the radio access part of the UMTS 3G standard – was designed to be a future-proof, highly-advanced 3G system for the global market. But there are many misconceptions about its development.

Firstly, WCDMA has no relation to and is not based on the IS-95 standard (or its later extension CDMA2000). Instead, WCDMA is the result of parallel European and Japanese 3G developments that were initiated in the early 1990s and in 1997 merged to create today’s global WCDMA standard.
 

Secondly, although WCDMA and IS-95 both use Code Division Multiplex Access (CDMA) technology invented more than 50 years ago, very different specific technical solutions have been adopted within the two standards, mainly as a result of 3G versus 2G requirements. Also, since WCDMA’s commercial deployment was planned for several years after that of IS-95, more advanced solutions could be chosen in WCDMA. The evolution of IS-95 into CDMA2000 happened after the physical layer of WCDMA was already defined and some technologies from WCDMA could therefore be incorporated into CDMA2000.

It is important to realize how WCDMA has developed, especially because of the promotion of fair, reasonable and non-discriminatory (FRAND) royalties for patents that are essential to WCDMA. This paper describes some of the technologies behind WCDMA and attempts to clarify the technology contribution landscape.