Interference often stands in the way of effective communications. In third-generation (3G) wireless-communications systems, interference can degrade the quality of service (QoS), decrease efficiency, and bring the data rates of digital communications networks to a crawl. Fortunately, a company called TensorComm (Westminster, CO, www.tensorcomm.com) has developed an innovative technique for dealing with interference known as Interference Cancellation Technology (ICT). Application of the firm's receiver technology promises to dramatically improve the performance of 3G and fourth-generation (4G) cellular networks in terms of data rates, spectral efficiency, and user capacity.
The interference cancellation techniques apply to coded wireless data and voice networks, notably those using code-division-multiple-access (CDMA) and wideband-CDMA (WCDMA) technologies. The technology can be delivered via a variety of integration options, including an application-specific-integrated-circuit (ASIC) solution for mobile handsets that requires no changes in product form factor or RF redesign or even enhancements to the wireless infrastructure. The ICT technology is designed to work at baseband and to improve the performance of the wireless downlink. It is capable of being applied to all 3G wireless protocols and is capable of canceling interference from all channels in a signal (including the overhead and traffic channels), whether that interference is from adjacent base stations or from multipath signals resulting from the terrain conditions.
The ICT approach can also complement other wireless "performance improvement" technologies, such as multiple-antenna receive-diversity (RD) techniques. For most conditions, a single-antenna ICT-enabled wireless device will provide comparable performance to a dual-antenna RD device, but at lower cost (due to the decreased parts count). But when used with RD technology, ICT can increase both the data throughput and sector capacity in the system.
In tests performed on 2.5G wireless networks within a major operator's commercial CDMA network, with a handset developed by a leading manufacturer, the test results showed dramatic improvements in performance following a series of exercises. These included base-station emulation in TensorComm's laboratory, basestation testing in the wireless operator's laboratory, and drive testing on the operator's commercial network. The network test recorded the reduction in base-station transmit power from base-station logs for handsets enabled with ICT compared to identical handsets without ICT. The test results included a gain increase of 2 dB across the network when averaged over time-varying conditions of mobility and location with respect to serving and adjacent base stations, as well as a reduction in base-station power by as much as 6 dB. In laboratory demonstrations, the use of ICT has resulted in a 44-percent decrease in the time required to transfer a data file over a wireless network.
Although small in terms of its numbers, with a total of only 22 employees, TensorComm packs a great deal of brainpower for its size, with 17 Ph.D.s or holders of the Master's Degree among them. Since 2001, the firm has been busy developing intellectual property (IP) and recently announced its 75th patent filing related to interference cancellation. The 75th filing specifically addressed the use of ICT for networks deploying multiple-input, multiple-output (MIMO) technologies. The company's co-founder and CEO, Dr. John Thomas, formerly of NASA's Jet Propulsion Laboratory (JPL), notes: "Interference cancellation solutions must be implemented as operators face the challenge of improving network performance and efficiency while increasing customer satisfaction. TensorComm is actively working with operators and their suppliers to apply ICT and gain more efficient use of wireless spectrum in 3G and 4G networks. The most important effect of ICT is the delivery of higher data rates over a wider coverage area."
The company has proven in several field trials that ICT is an effective weapon against interference in coded wireless networks. It can provide operators with higher data rates, increased capacity, and improved coverage. The end result is a satisfied customer and a cost-effective wireless network. For more information on TensorComm, visit the company's website at www.tensorcomm.com