On a typical WiFi channel, it would be difficult to obtain speeds matching the claimed 54 Mbps performance. Siemens Communications Group said it has demonstrated that its new MIMO system (multiple antennas providing Multiple Input and Multiple Output) can provide wireless links to mobile devices at a speed of 1 Gbps which would set a new world record. The comparison isn't completely fair, however, because the experimental system used a bandwidth of 100 MHz at 5-GHz, more than the typical 802.11a WiFi system requires.
In the Siemens news release, Mobile communications speed record: One gigabit per second over the air, Christoph Caselitz, the President of Siemens' Mobile Networks Division, explained, "By the time the next generation of mobile communication debuts-- which is expected to occur beginning in the year 2015--the need for transmission capacities for voice, data, image and multimedia is conservatively anticipated to rise by a factor of 10. Future mobile communication systems will have to utilize the frequency band as efficiently as possible, with the lowest possible transmit power.."
I described MIMO technology in the August 17, 2004 RF Report. Siemens said the use of MIMO technology has been limited due to the large amount of computing power required at the receiving end. "This exceeds the capabilities of the typical chips that are currently being employed in the mobile communication industry," according to Siemens. Its researchers overcame this challenge by developing new and optimizing signal processing algorithms that can be efficiently implemented on the hardware modules that are available today."
