[Wireless Japan] DoCoMo Demonstrates LTE System for 1st Time

Jul 23, 2008
Tetsuo Nozawa, Nikkei Electronics
The "mobile station" and visitors lining up to view the inside. Five of the mobile station's antennas were erected.
The "mobile station" and visitors lining up to view the inside. Five of the mobile station's antennas were erected.
[Click to enlarge image]
The ASIC to separate MIMO signals. The die measures 8.4 x 4.2mm, but the package's sides are as long as several centimeters. "It's because many test circuits were added," DoCoMo said.
The ASIC to separate MIMO signals. The die measures 8.4 x 4.2mm, but the package's sides are as long as several centimeters. "It's because many test circuits were added," DoCoMo said.
[Click to enlarge image]

NTT DoCoMo Inc is demonstrating a system supporting the LTE (long term evolution) wireless specification, which it calls "Super3G," at Wireless Japan 2008, which runs from July 22 to 24, 2008, at Tokyo Big Sight.

"We didn't transmit radio waves when we demonstrated the system before at another exhibition in Japan," DoCoMo said. "This is the first demonstration of radio communications using a licensed wireless station for the test."

The demonstrated system is equipped with an LTE 4 x 4 MIMO. The mobile station uses an entire truck. The exhibit was proving popular, with people lining up for several meters and waiting for 30 minutes to view the inside of the bus, DoCoMo said.

Downstream (from the base station system to mobile station) and upstream used 1.7GHz and 20MHz bandwidths in the demonstration, respectively. When using the 4 x 4 MIMO, maximum data rates were 250Mbps when uploading and about 50Mbps when downloading.

NTT DoCoMo also displayed an ASIC packaging "QRM-MLD technology," its proprietary algorithm to separate MIMO signals, alongside the demonstration. The ASIC die measures 8.4 x 4.2mm.

The chip was manufactured using 65nm process technology. Its circuit includes several millions of gates. The power consumption is as small as 79.2mW. "Now the ASIC can be mounted on LTE handsets," DoCoMo said.

The company is planning to "complete the development of a commercial system and start establishing infrastructure at the end of 2009."