Radio transmission technologies for IMT-2000 are being studied and standardized all over the world. Several national/regional standardization bodies are developing proposals on radio transmission technologies to meet the cut off date of June 30, 1998 set by ITU. This paper shows necessity to develop and standardize IMT-2000 in Japan, principle attitude on IMT-2000 standardization, selection process of W-CDMA, and the current situation of study on IMT-2000 in ARIB (Association of Radio Industries and Businesses).

ITU (International Telecommunication Union) has issued request for submission of candidate technologies for IMT (International Mobile Telecommunication)-2000/FPLMTS radio interface in April 1997. In order to propose a candidate technology and to contribute to the production of a world wide standard of IMT-2000, ARIB (Association of Radio Industries and Businesses) has studied radio transmission technologies for IMT-2000. This paper shows the recent study results on IMT-2000 radio transmission technologies in ARIB. Now in ARIB detailed study to produce necessary specifications and prepare of a proposal on candidate radio transmission technology to ITU are being conduced based on wide band DS-CDMA technologies.

Research and standardization activities on FPLMTS are under way throughout the world. This paper shows recent study results on radio transmission technologies in ARIB (Association of Radio Industries and Businesses), which in the standardization organization in Japan. On-going study shows two TDMA based and four CDMA based radio transmission technologies under study. These technologies need to be further studied in detail. The proposal from ARIB is expected to be summarized around the end of the year 1996.