Wireless Lan (WLAN)
Statistical Range Analysis in RF Systems: the "Range Fallacy"
You read every paper you could get your hands on to do with propagation and path loss at the frequency you're using, and you carefully included all the known (and measured) losses, antenna gains, power outputs and sensitivities in a detailed link budget. A few days later the marketing dept arrives at your office: "You said the range would be 5 meters but we tried it at that distance and we could make it fail." What has gone wrong?
Tips and tricks for predicting real-world 802.11n wireless performance
Wireless testing too often revolves around hooking up a handful or so of laptops, PDAs, IP phones and other mobile devices and blitzing the network with traffic. Although informative, this gives no visibility into the nuances of large networks. Think scalability, degradation and traffic differentiation.
Suppressing and containing? Try spread spectrum clocking to reduce EMI
Two EMI reduction methods are suppression (filtering) and containment (shielding), but they have disadvantages. In contrast, spread spectrum clocking (SSC) is an efficient, effective and less costly alternative method for controlling EMI. SSC reduces EMI peaks by spreading the energy from a clock across a wider frequency band.
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WiMAX/Fixed Broadband Wireless
DSP or FPGA? How to choose the right device
DSPs and FPGAs both offer advantages for signal processing. Here are the design guidelines you need to choose between DSPs, FPGAs, or a combination of the two. Topics covered include device cost, performance, NRE, and availability of application-specific features.
Tips and Tricks: Accelerate WiMAX rollout with remote testing
Here's how a risk mitigation mechanism called 'remote testing' enables WiMAX equipment manufacturers to test their equipments onsite to speed up deployment
C-based coprocessor design, part 1: SIMD architecture
Here's how CebaTech's C2R C-to-RTL compiler was used to implement a G723.1 and G729.A speech coding accelerator. The accelerator, which attaches to a scalar processor core, features configurable micro-architecture and instruction-set architecture.
See all WiMAX/Fixed Broadband Wireless »
Bluetooth
How Bluetooth and 802.11 will team up to deliver high speed wireless connections
The heart of Bluetooth high-speed technology is the concept of the Generic Alternate MAC/PHY (Generic AMP), an innovative solution for radio substitution that allows the Bluetooth stack to dynamically select the right radio for any application.
Annals of Wireless: Behind the scenes at the creation of the first Bluetooth headset
"We had tried infrared and inductive technologies and turned them down. We had a so-called belt-pack solution with the headset connected to a small box you were wearing in your belt."
Under the Hood: GPS Special - Garmin nuvi 750 vs. HP iPaq 310
TechOnline's Greg Quirk went inside the Garmin nuvi 750 and HP iPaq 310 GPS navigation systems to find that while they did have some crossover in terms of components, such as the use of chips from SiRF and Wolfson, they both came up with their own distinct approach to how a GPS navigation system should be designed.
See all Bluetooth »
Ultrawideband
60GHz: Achieving the ultimate wireless dream
Using sophisticated design and fabrication techniques, research labs are getting closer to realizing 60GHz chips in silicon. When that happens, consumer price points can be met and wireless design becomes a whole new ballgame. But first, engineers must overcome five major challenges.
How Bluetooth, UWB, and 802.11 stack up on power consumption
Digital still cameras, mobile phones and personal media players require high bandwidth and low power consumption, and therefore also demand a wireless data connectivity technology capable of addressing these needs.
Using programmable spread spectrum clock generators for EMI Reduction
To control EMI in consumer devices clock parameters like PLL charge pump current, VCO gain, and output drive strength, need to be programmable to improve system performance, reduce development time, and allows last minute changes.
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ZigBee/Mesh Networking
Embedded Linux: With friends like these, who needs enemies?
If embedded Linux champions are saying that embedded Linux is terrible, why would anyone want to risk their products or their company on it?
Statistical Range Analysis in RF Systems: the "Range Fallacy"
You read every paper you could get your hands on to do with propagation and path loss at the frequency you're using, and you carefully included all the known (and measured) losses, antenna gains, power outputs and sensitivities in a detailed link budget. A few days later the marketing dept arrives at your office: "You said the range would be 5 meters but we tried it at that distance and we could make it fail." What has gone wrong?
Analyzing circuit sensitivity for analog circuit design
Delve deep into the mathematics of filters and their sensitivities to component variations, using tools such as Monte Carlo analysis to determine how much a filter's transfer function will vary.
See all ZigBee/Mesh Networking »
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WIRELESSNET DESIGN CENTER ARCHIVE
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About the Wireless Net DesignLine How-To Section
Wireless Net DesignLine's How-To Section delivers detailed engineering articles focused on the design and development of IEEE 802.11 wireless AN (WLAN, WiMAX, fixed broadband wireless, ZigBee, wireless mesh networking, ultrawideband (UWB), Bluetooth, and Enhanced Data Rate (EDR) Bluetooth designs. Design topics covered in this category include radio frequency (RF) design, antenna engineering, baseband processor, memory designs, media access controller (MAC) design, and more.
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