Howtosignalprocessing
- Why ifft is used in OFDM transmitter?
- What is an OFDM subcarrier?
- Why IFFT and FFT is used in OFDM?
- What happens if number of subcarrier is increased?
Why ifft is used in OFDM transmitter?
The IFFT output is the summation of all N sinusoids. Thus, the IFFT block provides a simple way to modulate data onto N orthogonal subcarriers. The block of N output samples from the IFFT make up a single OFDM symbol.
What is an OFDM subcarrier?
Cellphone data uses subcarriers in OFDM and OFDMA arrangements to transmit data from the base station to the handset. In LTE, each subcarrier is spaced 15 kHz apart. These subcarriers are combined in groups of 12 to form a single resource block.
Why IFFT and FFT is used in OFDM?
The OFDM signal is generated by implementing the Inverse Fast Fourier Transform (IFFT) at the transmitter which is used to convert frequency domain to time domain and Fast Fourier Transform (FFT) which is used to convert time domain to frequency domain at the receiver side is implemented.
What happens if number of subcarrier is increased?
The results obtained showed that as the number of subcarriers increased from 32, through 64 to 128, the BER increased accordingly for all the mobile speeds considered and the effect is more noticeable at high signal-to-noise ratio. The increase in bit error rate indicates performance degradation.
