High accuracy Hilbert transformer realization for multicarrier communications

The basic motivation for this work is to investigate how Hilbert transformer (HT) design optimization can influence the Bit Error Ratio (BER) performance of a multicarrier wireless system. The implementation of a novel digital allpass based HT is proposed. The HT realization is based on worst-case phase-sensitivity minimization of each individual allpass section used. This design procedure allows to improve the accuracy of the HT phase deviation even in the cases of severe wordlength limitations and fixed point arithmetic applications. A multicarrier wireless system is simulated and it is experimentally demonstrated that the low sensitivity HT design procedure can improve the BER performance. AWGN and Rayleigh wireless channels are considered.