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What is subcarrier spacing in OFDM?
Subcarrier spacing is equal to the reciprocal of the symbol time. As a result of the longer symbol time, the subcarrier size and spacing decreases from 312.5 KHz to 78.125 KHz. The narrow subcarrier spacing allows better equalization and therefore enhanced channel robustness.
Which of the following is the condition for flat fading?
Explanation: The received signal will undergo flat fading if mobile radio channel has a constant gain and linear phase response over a bandwidth which is greater than the bandwidth of transmitted signal. It is the most common type of fading.
What is flat fading?
flat fading: Fading in which all frequency components of a received radio signal vary in the same proportion simultaneously. (
What is the subcarrier spacing between subcarriers in 4g?
15 kHz
In addition to this the subcarriers spacing is 15 kHz, i.e. the LTE subcarriers are spaced 15 kHz apart from each other. To maintain orthogonality, this gives a symbol rate of 1 / 15 kHz = of 66.7 µs. Each subcarrier is able to carry data at a maximum rate of 15 ksps (kilosymbols per second).
What is the difference between flat fading and selective fading?
➨In flat fading, range of frequencies in a frequency spectrum are equally faded unlike in frequency selective fading where in one part of frequency spectrum is faded more than the other part of frequency spectrum.
What is the spacing between the subcarriers in OFDM?
As a result of the longer symbol time, the subcarrier size and spacing decreases from 312.5 KHz to 78.125 KHz. The narrow subcarrier spacing allows better equalization and therefore enhanced channel robustness.
Which is longer 802.11ax or OFDM subcarriers?
Each OFDM subcarrier is 312.5 KHz. 802.11ax introduces a longer OFDM symbol time of 12.8 μs, which is four times longer than the legacy symbol time of 3.2 μs. Subcarrier spacing is equal to the reciprocal of the symbol time. As a result of the longer symbol time, the subcarrier size and spacing decreases from 312.5 KHz to 78.125 KHz.
How are subcarrier spacing related to symbol time?
Subcarrier spacing is equal to the reciprocal of the symbol time. As a result of the longer symbol time, the subcarrier size and spacing decreases from 312.5 KHz to 78.125 KHz. The narrow subcarrier spacing allows better equalization and therefore enhanced channel robustness.
How many subcarriers are there in a FFT?
11a, however, the FFT size is typically 64; with a sample rate of 20 MHz, this yields a subcarrier spacing of 312.5 kHz. Of these 64 potential subcarriers, 12 of them are unused (sometimes referred to as “virtual carriers”).