Pulses With Minimum Residual Intersymbol Interference for Faster Than Nyquist Signaling

Faster than Nyquist signaling increases the spectral efficiency of pulse amplitude modulation by accepting intersymbol interference, where an equalizer is needed at receiver. Since complexity optimal exponentially with number interfering symbols, practical truncated equalizers assume shorter memory. The power resulting residual interference depends on transmit filter and limits performance equalizers. In this paper, we use numerical optimizations prolate spheroidal wave functions to find time-limited pulses that achieve minimum interference. Compared root raised cosine pulses, new decrease order magnitude, for example, a 32 dB achieved considers four symbols 57% faster transmissions. As proof concept, transmissions binary showed using 4-state has better bit error rate compared 128-state equalizer.