Advanced spectral processing based MIMO receiver algorithms not requiring a cyclic prefix. Case study: UMTS-HSDPA and HSUPA multi-code reception

Channel spectral equalisation, a low complexity receiver processing based on FFT, is used in OFDM systems in conjunction with a cyclic prefix in transmission. The technique is applicable, beyond OFDM, also to single carrier systems, such as TDMA and CDMA, which however do not employ cyclic prefix. Spectral equalization not using cyclic prefix has been recently introduced for these systems. In this paper a novel spectral equaliser not requiring cyclic prefix, based on the spectral factorisation of circulant matrices, is introduced for single carrier systems, with applications to CDMA: UMTS FDD-HSDPA and HSUPA systems, SISO and MIMO.