NTT DoCoMo, Inc. announced today plans for a field trial of a fourth-generation (4G) mobile communications system in Yokosuka, Kanagawa Prefecture, where a DoCoMo R&D center is located.
DoCoMo has been conducting research on 4G mobile communications technology since 1998. In indoor experiments announced last October, DoCoMo's 4G system demonstrated maximum information bit rates of 100 Mbps for the downlink and 20 Mbps for the uplink.
The field trial announced today is DoCoMo's next step toward the development of practical 4G technologies, as well as a further contribution by the company toward the establishment of a 4G global standard, which is now being discussed by the International Telecommunication Union's Radiocommunication Sector. (ITU-R).
The field trial will employ Variable Spreading Factor Orthogonal Frequency and Code Division Multiplexing (VSF-OFCDM) and Variable Spreading Factor Code Division Multiple Access (VSF-CDMA) technologies. VSF-OFCDM enables downlink connections of extremely high speeds, both indoors and outdoors, while VSF-CDMA realizes high-speed, high-efficiency packet transmissions for the uplink.
DoCoMo will evaluate the following high-speed transmissions technologies during the field trial:
Effective packet transmission methods
Adaptive modulation and channel coding scheme
Adaptive retransmission control
Adaptive beam forming based on predicted direction of arrival
The Kanto Bureau of Telecommunications granted DoCoMo a preliminary license to conduct the field trial today.