Effects of Variable Time Window Width and Signal Position Within FFT Bin on WISPRPerformance

摘要

The effect of variable width of the time window in time frequency analysis onWISPR performance is investigated, along with the effect of signal position within the signal bin. The results demonstrate that variable width of the time window in FFT/DFT calculations has only a small effect on WISPR performance, as long as the full signal energy is contained within the signal bin. But the loss of even a small portion of the signal energy from the signal bin has a dramatic effect on the WISPR level, and causes deterioration in WISPR performance by several decibels. The average power level is only slightly affected by such changes. The sensitivity of the WISPR level to the signal position within the signal bin provides a means to determine the signal frequency more precisely, avoiding the necessity to carry out calculations using much larger data sets.