On the performance of filter bank based multicarrier systems in xDSL and WLAN applications

We consider filter bank based multicarrier systems which have been considered for fast digital subscriber line applications and possibly could be interesting also for broadband wireless LAN applications. In addition to being resistant to narrowband interference, these systems provide better spectral shaping than DFT-based OFDM and DMT systems for the subchannels, as well as for the overall signal. Furthermore, they provide better efficiency because the time-domain guard interval is not needed and the guard-band in frequency domain can be reduced. The channel equalization for such systems has been an open problem, but the paper demonstrates that it can be solved, at least in principle, even though effective adaptive equalization algorithms are still under development. Another open question is the performance when nonlinearities are included in the chain, especially in the transmitter power amplifier. In the paper, it is demonstrated that the performance of filter bank based systems with nonlinear power amplifiers is only slightly worse than in the corresponding OFDM/DMT systems. When the number of channels is the same, no more than 1 dB higher input backoff is required.