Technical Wireless Articles
Links to wireless, cellular and communications technical articles and whitepapers at other sites that we found of interest.
Tower Mounted Amplifiers (TMAs)
- Tower-top amplifiers and noise figure (Part 1 of 2) – Part 2 of 2
- Tower-top amplifiers and noise figure
- Testing Tower Top Amplifiers (TTA) – The proliferation of the cellular telephones, PCS telephones, low power two-way radios, and wireless LANs, has created a need for tower top amplifiers (TTA)
- Tower Mounted Amplifiers – Diagnostics and Isolations Measurements – How to use a Anritsu Sitemaster S251C to test TMAs.
- TMA CDMA Coverage – A mathematical explanation of the benefits of using Tower Mounted Amplifiers (TMAs) in a CDMA system – Base Station Earth Station Magazine.
- TMAs Alleviate Cellular Network Strain – Although they offer cost and performance benefits, tower-mounted amplifiers must still prove themselves against interference. – Wireless Systems Design Magazine
Intermodulation
- Intermod: Getting the upper hand (Part 1)
- Intermod: Getting the upper hand (Part 2)
- Intermodulation Distortion Problems at UMTS Cell Sites – by Adrian Nash, Aeroflex Wireless Test Solutions – With the introduction of 3G, the co-existence of 3G and 2G radio networks has become a major issue both from a network planning perspective and for realisable network performance. This paper presents the problems that may be encountered in co-location of 2G and 3G cells caused by Passive Intermodulation Distortion (PIM) and blocking.
- The impact of intermodulation interference in superimposed 2G and 3G wireless networks and optimization issues of the provided QoS – by G. Paschos, S. A. Kotsopoulos, D. A. Zogas, and G. K. Karagiannidis – This paper investigates the critical parameters that affect the overall opera-tion of the systems that belong to different competing wireless communication consortia.
- Computer analysis of intermod requires a pragmatic approach – A prescription for an effective computer program to calculate intermod includes practical and user-friendly techniques for entering and analyzing data.
Interference and Noise
- Evaluating Noise – What “noise” means in a cellualy system depends on whomm you’re talking to.
- Filtering Interference From Cellular Receivers – Band-reject filters can be applied quite effectively in reducing or removing unwanted IMD interference signals from the operating band of a cellular receiver system.
- Reduce noise in distributed communications systems – Back-end design fixes cannot improve a bad “noise lunch” at the radio system input, but tower -mounted amplifiers can improve overall system noise figure.
- Transmitter noise/ receiver desense primer – When locating multiple stations at a single site, several precautions must be taken to guard against interference to all stations at the site. Among factors to be considered are transmitter noise and receiver desensitization.
- Site noise vs. system noise figure – No matter how good the noise figure of individual components of a receiving system may be, it is the overall system noise figure that represents the…
- Co-channel interference: How bad is it? – As the land mobile radio frequency spectrum has become overcrowded, interference has become the rule, rather than the exception.
- Measuring 800MHz interference
- Filtering compromises from Co-located Systems – The cocktail of co-located spectrum and cell-based wireless services is leading to interference issues that can severely impact network performance, although custom co-location RF filters offer a practical solution.
RF Measurements
- Using and converting RF units of measure – Many RF measuring units, as well as various forms of those measuring units, are in use today.
- Ready, set, calculate – Erlangs? Queuing? Grade of service? Once you know the basics, you can use software to analyze trunked system capacity. Follow these steps to practical capacity planning for your radio system.
- Transmission line measurements
- SWR, impedance and line loss – Standing waves on a transmission line affects both the impedance seen at the input and the overall loss of the transmission line the higher the SWR, the greater the effect on these parameters.
- Clarify Antenna Gain for Accurate Mobile Measurements – Understanding the true meaning of “Antenna gain” can help improve the accuracy of handset measurements.
Miscellaneous
- The finer point of re-banding
- Demystifying RF attenuators
- Ensuring RF is a multi-faceted task
- Getting back to basics: Filter terminology – Filters are indispensable in radio communications systems. Receivers and transmitters use them in RF stages, intermediate frequency stages and audio frequency stages. Much of the basic filter terminology applies to all types of filters used in receivers, transmitters, multicouplers, combiners and antenna systems.
- Microwave path design – The Basics – This series of four articles is a primer on some of the propagation-related basics of microwave path design. – Part 4, Part 3, Part 2, Part 1
- Feed design and selection for microwave antennas
- Is your two-way radio system balanced? – The base station noise floor, vehicle noise and ambient noise in the service area can all contribute to throwing a radio system out of balance. Here’s how to fix it.
- Predicting Radio Channel Capacity – This article discusses how the capacity of a conventional two-way radio channel can be predicted by using a model that compares the behavior of human users on conventional voice channels to that of packets in a data transmission. Comparisons to the efficiencies in a trunked radio system are also discussed.
- RF samplers and Directional Couplers
- Antenna system troubleshooting simplified
- Data above voice systems - In the last 20 years, long-haul transmission networks were upgraded to transport digital signals due to the huge growth of the information
- Technical techniques: A primer for transmission lines Part 1 , Part 2
- Antenna system troubleshooting simplified – What is the quick est and most efficient way to determine the root cause of a failed transmission system?
- Suppressing Errors in WCDMA Mobile Devices – As the final specs for WCDMA near completion, handset designs offering wireless Internet access with voice and data capabilities are close behind. But to make these products a reality, designers must first get a grip on minimizing BER in the RF front end. – Communications Systems Design Magazine
- Ericsson White papers – A collection of technical white papers from Ericsson.
- Can multicarrier PAs resurrect old cell-site assests? – Multicarrier power amplifiers (MCPAs) claim much in terms of flexibility, adaptability, and the range of applications in which they can be employed. Is all this hype justified, especially from a technology with its roots in a 1920s patent?
- Pico Cells, Femto Cells, and DAS – Spurred by new products from vendors such as ipaccess, Ubiquisys, 3Way, and Motorola, the marketplace has shown growing interest in pico and femto cells as a solution for in-building wireless connectivity.
- CDG Whitepapers – A selection of whitepapers on 3G CDMA2000 and CDMA Technology.
