User:Pravindrakumar iit/sandbox

Bandwidth Efficiency Comparison between single carrier and multicarrier optical transmission system
The performance of any communication system is can be measured in terms of its power efficiency and bandwidth efficiency. The power efficiency describes the ability of communication system to preserve bit error rate (BER)of the transmitted signal at low power levels. Bandwidth efficiency reflects how efficiently the allocated bandwidth is utilized and is defined as the throughput data rate per Hertz in a given bandwidth. If the large number of subcarriers are used, the bandwidth efficiency of multicarrier system such as OFDM is defined as[1] Factor 2 is because of two polarization states in the fiber.
 * $$\eta=2.\frac{R_{s}}{B_{OFDM}}$$

There is saving of bandwidth by using Multicarrier modulation with orthogonal frequency division multiplexing. So the bandwidth for multicarrier system is less in comparison with single carrier system and hence bandwidth efficiency of multicarrier system is larger than single carrier system.

From the table we see that there is only 0.5dB reduction in receiver power, but we get 76.7% improvement in Bandwidth efficiency with using multicarrier transmission technique