For both scenarios, the main parameters used in the simulations are, FFT size of 1024; number of resources, i.e., available subcarriers (Nc) shared by the K users set to 16; sampling frequency set to 15.36 MHz; useful symbol duration is 66.6 μs; cyclic prefix duration is 5.21 μs; overall OFDM symbol duration is 71.86 μs; subcarrier separation is 15 kHz; and modulation is 4-QAM.
T is the OFDM symbol period, T = Tcp + T u, T u = Δf K is the useful symbol duration, and Tcp is the cyclic prefix duration.
Suppose the time length of cyclic prefix is and the useful data duration is.
2K mode:1705 active subcarriers, subcarrier spacing: 4.464 kHz, useful symbol duration: 224 microseconds, constellation: 16 QAM.
The source signal for simulations was an OFDM signal, similar to the DVB-T standard signal [2], with the following parameters: (i) 2K mode:1705 active subcarriers, (ii) subcarrier spacing: 4.464 kHz, (iii) useful symbol duration: 224 microseconds, (iv) constellation: 16 QAM.
T and Δ are the useful OFDM symbol duration and the CP duration, respectively.
Each OFDM symbol has a useful part of duration seconds and a cyclic prefix of length seconds to mitigate ISI, where is longer than the channel-response length.
Another useful measure is duration, or the amount of principal a bond will lose if interest rates rise at least one percentage point.
The value of is larger or equal to the maximum multipath delay spread of the channel, and is small in respect to (a useful OFDM symbol duration) to limit the spectral efficiency loss.
Even in low-degree to moderate stenosis, in which the local increase of velocity can be easily detected by conventional US Doppler techniques, VFI provides a better understanding of disturbed flow extension and duration, useful in the medical management of carotid stenosis (Fig. 10, Vid 10b, 10c).
