Serial and Parallel Concatenations Based on Faster Than Nyquist Signaling

We investigate the performance of concatenated coding schemes based on faster than Nyquist (FTN) signaling over the AWGN channel. We test both serial and parallel concatenations. In serial concatenation the FTN signaling is considered as the inner encoder and the outer code is a rate b/c convolutional code. In parallel schemes we use two parallel Gaussian channels and transmit FTN pulse trains in both; here a precoding device turns out to be crucial. The convergence behaviour is analysed using EXIT charts. The overall spectral density of the schemes varies but is roughly 1-2 bit/s/Hz. The results, in terms of needed E _b/N₀ for reliable communication versus spectral density, are very good