MOTOROLA RESEARCHES TECHNOLOGIES TO ENHANCE 3G.

Researchers at Motorola Labs have researched potential technologies to significantly enhance the performance of 3G.

"3G standards are continuing to evolve as the industry moves through 3GPP Releases 4 and 5 and 3GPP2 technologies, such as 1xEVDV. Motorola and others are working on various approaches in order to determine optimum standards and system requirements, but one thing that is certain is that the technology needs to deliver higher data rates to the consumer at a lower cost per data bit," said Dennis Roberson, executive vice president and chief technology officer, Motorola, Inc (NYSE:MOT).

One technology that has been proposed for delivering that higher data rate at a lower per-bit cost is the use of multiple antennas for both the cellular site and handsets. Theoretically, multiple antennas have been shown to enable major increases in the data capacity, peak data rate and voice capacity. However, the actual achievable performance depends on the properties of the radio signal propagation environment. Accurate models that characterize the propagation environment are key to predicting the true channel capacity improvements.

Researchers at Motorola Labs have built and deployed a world-class measurement system that supports the study of such multiple antenna technologies for channel bandwidths of up to 5 MHz. They are also actively involved in the standards process for setting the channel models that will be used in determining which technologies will ultimately be written into the standards.

How it Works

With multiple antennas, different signals are transmitted from each antenna and the signals are then received by multiple antennas and deciphered. Motorola Labs' channel measurement system enables virtually simultaneous measurement of the propagation paths between all combinations of site and user equipment antennas in both the uplink and downlink directions. The channel measurements are repeated 1600 times per second continuously along the entire drive route. This is fast enough to follow variations in the channel due to the motion of the test vehicle. This in turn enables the development and evaluation of channel models that mathematically describe what happens between all of the transmitting and receiving antennas. The channel models can then be used in simulations that model the signal processing in the cellular handsets and base stations to predict the channel capacity, peak data rate and voice capacity.

"Motorola's system enables the measurement of more transmission variables than anyone that we know of to date," said Walt Rozanski, director of the Ft. Worth Research Lab. "This puts us a step ahead of our competitors when it comes to determining how to make multiple antenna systems provide a benefit to the user."

Motorola Labs' channel measurement system was installed at two sites in an urban area, and a PDA and laptop were each fitted with four antennas to create a real world user test. Trials have also been conducted using cellular handset prototypes that have multiple antennas. More than 2,000 gigabytes of channel data have been collected so far, enabling evaluation of various multiple antenna technologies such as transmit and receive diversity, beamforming and MIMO (Multiple Input, Multiple Output) .

The performance evaluation confirmed that significant improvements in both data and voice capacity are achievable in the mobile environment.

"This demonstrates that multiple antenna technologies have the potential to improve the delivery of content-rich mobile broadband applications. But as you'd expect, this needs to be balanced against the extra costs of multiple antenna technologies, the operator's investment in existing hardware, market timing factors and many other issues," said Rozanski. "However, overall this work has put Motorola in a leading position in this field and will allow us to determine the actual benefit of these technologies to our customers."

Motorola, Inc. (NYSE:MOT) is a provider of integrated communications and embedded electronic solutions. Sales in 2001 were $30 billion. Motorola Labs is the research arm of Motorola, Inc., with a strong, global team of scientists and engineers focused on discovering and developing new materials, technologies, architectures, algorithms and processes for future systems, products and product enhancements. Motorola actively licenses technologies developed in the Labs.

Motorola can be found on the World Wide Web at http://www.motorola.com/.

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