Improved Nyquist Filters with Piece-Wise Parabolic Frequency Characteristics

Construction of new ISI-free pulses using a linear combination of two polynomial pulses

“…Based on this start point and to further improve the performance of the polynomial filters [3] and [4], we used a new linear combination of two pulses with different asymptotical decay rates.…”

“…In [4], it was investigated the performance of four new families of improved Nyquist filters (INFs) with piecewise frequency characteristic composed of concave and convex parabolic pieces. They show an asymptotic decay rate (ADR) of t −2 with comparable or better ISI performance as compared with several recently proposed pulses.…”

“…This work demonstrates that the solution to obtain an enhanced performance is to transfer an amount of energy into the high spectral region in order to get a more open eye in the eye diagram and slower rising pulse tails around the sampling moments. It showed that this can be done by shaping the frequency characteristic in the transition region [4].…”

“…In order to provide improved performance of some recently ISI-free pulses, we apply this method to a new set of Nyquist pulses [3,4].…”

“…The concept of improved Nyquist filter (INF) and the construction of parametric families originate with the work of Beaulieu et al [2,7]. Several contributions in this area were later reported in [1,3,4,[8][9][10][11][12][13][14][15][16]. The use of improved Nyquist pulses leads to a smaller error probability in the presence of timing jitter than the well-known RC pulse for the same excess bandwidth.…”