A MMSE successive interference cancellation scheme for a new adjustable hybrid spread OFDM system

The effects of uniform spreading in OFDM-CDMA systems is the harmonization at the reception of the signal to noise ratio between the sub-bands which prevents the good performance of successive decoding algorithms. This paper proposes a new hybrid spread OFDM (SOFDM) transmission scheme in which the spreading of the information is adjustable and not uniform along the carrier (frequency selective). Moreover a MMSE version of the V-BLAST successive interference cancellation algorithm suited for this hybrid modulator is derived. The performance of the combination of SHOFDM and MMSE V-BLAST is shown to both outperform COFDM and conventional and classical iterative detection algorithms for SOFDM in the realistic scenario of the 5 GHz HiperLAN/2 system.