Spectral overlay of multicarrier CDMA on existing CDMA mobile systems

A spectral overlay of a narrow-band code division multiple access (CDMA) system and a wide-band multicarrier CDMA system is considered as a means for existing CDMA mobile networks to evolve into a future CDMA network. The achievable joint capacity of the overlaid system is provided and compared with that of another network evolution strategy of spectrally overlaying wide-band single-carrier CDMA to the existing CDMA systems.