Qualcomm Inc (QCOM)

[Data_Rox]

NTT's VSF-OFCDM -- and variable spreading factor-CDMA (VSF-CDMA)
Communications Daily
May 29, 2003

NTT DoCoMo plans to conduct a trial of a 4th-generation wireless system at its R&D center in Yokosuka in Japan's Kanagawa Prefecture. DoCoMo, which has been researching 4G technology since 1998, said it had demonstrated maximum data rates of 100 Mbps for a downlink and 20 Mbps for an uplink as part of indoor experiments started last Oct. The field trial will evaluate variable spreading factor orthogonal frequency and code division multiplexing technology -- VSF-OFCDM -- and variable spreading factor-CDMA (VSF-CDMA). The company said VSF-OFCDM allowed downlink connections at very high speeds both indoors and outdoors. It said VSF-CDMA allowed high- speed, high-efficiency packet transmissions for the downlink. DoCoMo described the trial as the "next step toward the development of practical 4G technologies." It said it also was part of work on the establishment of a global 4G standard, now under discussion at the ITU. The Kanto Telecom Bureau granted DoCoMo a preliminary license Wed. to conduct the test, which is designed to evaluate: (1) Effective packet transmission methods. (2) Adaptive modulation and channel coding scheme. (3) Adaptive retransmission control. (4) Adaptive beam forming based on predicted direction of arrival.