NTT DoCoMo Achieves 1Gbps Packet Transmission in 4G Field Experiment

Jun 23, 2005

NTT DoCoMo, Inc. announced today that it achieved 1Gbps real-time packet transmission in the downlink at the moving speed of about 20km/h in a field experiment on fourth-generation (4G) radio access. The experiment took place in Yokosuka, Kanagawa Prefecture on May 9, 2005.

This is the latest achievement in DoCoMo's ongoing development of key radio access technology for 4G mobile communications.

The 1Gbps real-time packet transmission was realized through Variable Spreading Factor-Spread Orthogonal Frequency Division Multiplexing (VSF-Spread OFDM) radio access and 4-by-4 Multiple-Input-Multiple-Output (MIMO) multiplexing using "adaptive selection of surviving symbol replica candidate" (ASESS) based on Maximum Likelihood Detection with QR decomposition and the M-algorithm (QRM-MLD), which was developed by DoCoMo. By using the new algorithm, DoCoMo was able to reduce the large computational complexity of the original MLD method while maintaining almost the same achievable throughput performance. Frequency spectrum efficiency, which is expressed as information bits per second per Hertz, is 10 bits per second per Hertz, about 20 times that of 3G radio networks' spectrum efficiency.

During an earlier trial in July 2003, DoCoMo achieved 100Mbps and 20Mbps data rate transmission in the downlink and uplink, respectively, in outdoor environments using the same 100MHz bandwidth.

DoCoMo will continue to conduct field trials as part of its program to develop a 4G global standard in cooperation with the International Telecommunication Union Radiocommunication Sector. The telecommunications council of Japan's Ministry of Internal Affairs and Communications aims to see 4G services commercialized in the country by 2010.

Explore further: Samsung debuts new Nook tablet with larger screen

add to favorites email to friend print save as pdf

Related Stories

Field experiments of 4G LTE-advanced system underway

Feb 07, 2011

NTT DOCOMO announced today that on January 27 it was pre-licensed by the Kanto Bureau of Telecommunications of the Ministry of Internal Affairs and Communications for field experiments of LTE-Advanced, a true fourth-generation ...

Recommended for you

Tablets, cars drive AT&T wireless gains—not phones

44 minutes ago

AT&T says it gained 2 million wireless subscribers in the latest quarter, but most were from non-phone services such as tablets and Internet-connected cars. The company is facing pricing pressure from smaller rivals T-Mobile ...

Blink, point, solve an equation: Introducing PhotoMath

2 hours ago

"Ma, can I go now? My phone did my homework." PhotoMath, from the software development company MicroBlink, will make the student's phone do math homework. Just point the camera towards the mathematical expression, ...

Google unveils app for managing Gmail inboxes

2 hours ago

Google is introducing an application designed to make it easier for its Gmail users to find and manage important information that can often become buried in their inboxes.

'Silicon Beach' brings tech boom to Los Angeles

2 hours ago

So long Silicon Valley. These days entrepreneurs and engineers are flocking to a place better known for surfing waves than the Web. Amid the palm trees and purple sunsets of the Southern California coastline, ...

User comments : 0