SFN and OFDM
July 28th, 2008 questions and answers in my Advanced RF/Wireless Techniques class.
1. What is SFN?
SFN, or Single Frequency Network, is a broadcast network where several transmitters simultaneously send the same signal over the same frequency channel.
2. Why does OFDM enable SFN technique?
OFDM, or Orthogonal Frequency Division Multiplexing, which is used in wideband digital broadcasting, enables SFN technique in order to have efficient utilization of the radio spectrum, allowing a higher number of radio and TV programs in comparison to traditional multi-frequency network (MFN) transmission. An SFN may also increase the coverage area and decrease the outage probability in comparison to an MFN, since the total received signal strength may increase to positions midway between the transmitters.
SFN considerably improves the utilization of frequency bands and channels as well as energy balance of digital transmitters. The signal coverage of a certain area can be provided by a number of transmitters, transmitting the multiplex of digital television or radio signals in the identical frequency channel. Their partial signal contributions in the reception point not only do not interfere, under certain circumstances then even improve the reception.
3. What are the benefits of broadcasting using SFN?
The benefits of broadcasting using SFN are:
- Improvement in the utilization of frequency bands and channels in the available spectrum,
- Improved coverage area, and
- Decreased outage probability.
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This is definitely just a random post.