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Which algorithm eliminates the need for a training sequence and increases the spectral efficiency of the system?
Due to its good orthogonality, slantlet transform (SLT) is used in orthogonal frequency division multiplexing (OFDM) systems to reduce intersymbol interference (ISI) and intercarrier interference (ICI). This eliminates the need for cyclic prefix (CP) and increases the spectral efficiency of the design.
Which transmission scheme has the highest spectral efficiency?
The highest SE demonstrated so far for long-haul DWDM transmission is 7 b/s/Hz, which is based on PDM-OFDM with 32-QAM subcarrier modulation [26]. Eight 65.1 Gb/s PDM-OFDM-32QAM channels were transmitted over 3× 80 km SSMF spans with DRAs and EDFAs. The achieved SEDP was 1,680 km·b/s/Hz.
What is OFDM in communication?
In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission and a method of encoding digital data on multiple carrier frequencies. In OFDM, multiple closely spaced orthogonal subcarrier signals with overlapping spectra are transmitted to carry data in parallel.
Is the IFFT block really necessary in OFDM?
If we want to send a bunch of complex-numbers (vectors), then most OFDM discussions involve presenting those numbers to an IFFT block, and the output of the IFFT block will then have a bunch of complex numbers for which to transmit in a queued fashion through a QAM block. Can I ask —– is the IFFT block really necessary?
What does the ” O ” stand for in OFDM?
The “O” in OFDM stands for orthogonal. The IFFT takes a complex number (1 bin of the input) and turns it into samples of a sinusoid of a frequency that, over a certain length (of time), is orthogonal to (and thus, under ideal linear conditions, won’t interfere with) any other frequency subcarrier output by the IFFT.
Which is a principle of the principle of OFDM?
The basic principle of OFDM is to split a high‐rate data. stream into a number of lower rate streams and transmit.
Can you use a QAM block instead of Ifft?
Instead of using the IFFT block, is it possible to just place the original set of complex numbers (vectors) on the queue….and then transmit those numbers (real and imaginary components) – one at a time – through a QAM block? The signal (without using IFFT) is still going to be OFDM, right? Thanks for any comments/advice!