Time diversity is a technique common to most digital transmission systems. The Rake Receiver is used to find and demodulate multipath signals that are time delayed from the main signal. Rake Receiver to Find and Demodulate Multipath Signals. Data is Interleaved : Spreads Adjacent Data in time to Improve Error Correction Efficiency Convolutional Encoding : … Read more
Correlation Is a Measure of How Well a Given Signal Matches a Desired Code, The Desired Code is Compared to the Given Signal at Various Test times. Correlation is key enabling concept for direct sequence CDMA systems. Correlation is a measure of how well a given signal spread with a digital code matches a desired … Read more
Frequency diversity is inherent in a spread spectrum system. A fade of the entire signal is less likely than with narrow band systems. Combats Fading, Caused by Multipath Fading Acts like Notch Filter to a Wide Spectrum Signal May Notch only Part of Signal Fading is caused by reflected images of an RF signal arriving … Read more
CDMA extends the idea of diversity reception with the concept of soft handoff. In the slide, a mobile CDMA phone has established a call with base station one. As the mobile moves away from base station one and approaches base station two, a device in the phone known as the searcher identifies base station one … Read more
SEATTLE—T-Mobile USA Inc. and its parent company, Deutsche Telecom A.G., have been ordered by the U.S. Department of Labor to pay $345,972 to a worker allegedly fired for being a whistle-blower. Bellevue, Wash.-based T-Mobile said it plans to appeal. The Department of Labor’s order resulted from an investigation into alleged violations of the whistleblower protection … Read more