What are the Advantages of OFDMA in Wimax ?

 OFDMA is essentially a hybrid of FDMA and TDMA: Users are dynamically assigned subcarriers (FDMA) in different time slots (TDMA) . The advantages of OFDMA start with the advantages of…

CDMA Spatial Diversity

Diversity Reception: Multiple Antennas at Base Station Each Antenna is Affected by Multipath Differently Due to Their Different Location Allows Selection of the Signal Least Affected by Multipath Fading If…

What is CDMA Time Diversity ?

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….

How Frequency Diversity works in CDMA?

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…

Receive Diversity Selection and Switched Diversity

Make use of a number of receive antennas that are well separated (coherence distance) to generate independent receptions of the transmitted signal. Selection diversity: choose received signal with largest received…

How Frequency Diversity of Hopping in GSM

Hopping can lower the influence of Rayleigh fading to signal strength. This influence equals to frequency diversity. One voice code block of GSM is transmitted in 8 bursts separately after…