NTT DoCoMo, NEC, Fujitsu Jointly Develop Technology for 4G System to Raise Throughput to 1Gbps

http://neasia.nikkeibp.com/wcs/leaf/CID/onair/asabt/news/294489

March 8, 2004 (TOKYO) -- NTT DoCoMo Inc of Japan, NEC
Corp of Japan and Fujitsu Ltd of Japan have proposed a
technology for an orthogonal frequency and code
division multiplexing (OFCDM) system, a potential
candidate for the forth-generation (4G) mobile
communication system, which increases throughput to
1Gbps at a bandwidth of 100MHz.

According to NTT DoCoMo, the companies aimed to
achieve 1Gbps because the conventional throughput of
100Mbps is inadequate for base stations where there is
a high concentration of communications traffic in
small areas, including the hotspot environment. The
three companies reported the results of their
simulation at "Mobile Communications Workshop" held at
Yokosuka Research Park. 

It features multiple-input, multiple-output (MIMO)
multiple access, which uses multiple
transmitting/receiving antennas. An improved
throughput compared to the conventional MMSE method
was realized by adopting maximum likelihood detection
as the method to separate received signals from
multiple antennas. 

The simulation that demonstrated a throughput of 1Gbps
at a bandwidth of 100MHz used the following
conditions: a data modulation method of 16-QAM, and
turbo coding with a coding rate of 8/9. Four antennas
were employed for both transmission and reception. The
average reception Eb/No was 10dB, where the average
block error rate was 10-2. 


(Naoki Asakawa, Staff Editor, Nikkei Electronics)