Advantage and Disadvantage of OFDM

Answer 1

ADVANTAGES:

• Makes efficient use of the spectrum by allowing overlap.

• By dividing the channel into narrowband flat fading subchannels, OFDM is more resistant

to frequency selective fading than single carrier systems are.

• Eliminates ISI and IFI through use of a cyclic prefix.

• Using adequate channel coding and interleaving one can recover symbols lost due to the

frequency selectivity of the channel.

• Channel equalization becomes simpler than by using adaptive equalization techniques with

single carrier systems.

• It is possible to use maximum likelihood decoding with reasonable complexity.

• OFDM is computationally efficient by using FFT techniques to implement the modulation

and demodulation functions.

• Is less sensitive to sample timing offsets than single carrier systems are.

• Provides good protection against cochannel interference and impulsive parasitic noise.

DISADVANTAGES :

• The OFDM signal has a noise like amplitude with a very large dynamic range, therefore it

requires RF power amplifiers with a high peak to average power ratio.

• It is more sensitive to carrier frequency offset and drift than single carrier systems are due

to leakage of the DFT.