Square-root improved Nyquist filter with a piecewise rectangular frequency characteristic

In this paper, we propose and investigate a new improved Nyquist pulse with an asymptotic decay rate of t-2 produced by an improved Nyquist filter with a piece-wise rectangular frequency characteristic. Both the new pulse and the one produced by the square root filter have a closed form expression in time domain and outperform the previously reported pulses in several cases of commonly considered benchmark tests. They are also robust to the root and truncation operations, and suitable for OFDM systems implementation.