Now that we have reviewed the second generation systems, lets understand all the concepts that play a role in making these systems work!
In the last blog, I used words like FDD/TDD/FDMA etc.. Lets go into details of all these words..
In this blog we will dig deeper into Frequency division duplexing and time division duplexing
To begin with, lets see what is a duplex system.. A duplex system can send and receive functionality. Depending upon whether send and receive functions are done simultaneously, a system can be FULL duplex or half duplex. For point to multipoint networks like cellular systems , it is necessary to separate inward and outward signals.
1. Time division duplexing : It is a method of transmitting and receiving at the same frequency but having synchronized switches at both the ends. Although it is intuitive that TDM systems are synchronous, statistical time division multiplexing has been successfully implemented. The advantages include lower spectrum usage, lower cost of implementation than FDD, asymmetrical or dynamic UL/DL allocation.
2. Frequency Division duplexing : In this case there are two separate frequency channels are required. The cons include higher spectrum usage , no dynamic allocation. Advantages include lower(theoretically zero) latency.
In the last blog, I used words like FDD/TDD/FDMA etc.. Lets go into details of all these words..
In this blog we will dig deeper into Frequency division duplexing and time division duplexing
To begin with, lets see what is a duplex system.. A duplex system can send and receive functionality. Depending upon whether send and receive functions are done simultaneously, a system can be FULL duplex or half duplex. For point to multipoint networks like cellular systems , it is necessary to separate inward and outward signals.
1. Time division duplexing : It is a method of transmitting and receiving at the same frequency but having synchronized switches at both the ends. Although it is intuitive that TDM systems are synchronous, statistical time division multiplexing has been successfully implemented. The advantages include lower spectrum usage, lower cost of implementation than FDD, asymmetrical or dynamic UL/DL allocation.
2. Frequency Division duplexing : In this case there are two separate frequency channels are required. The cons include higher spectrum usage , no dynamic allocation. Advantages include lower(theoretically zero) latency.
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