Oblique Projection Based Receiver with Interference Cancellation in OFDMA Uplink

This paper presents an oblique projection-based detection scheme with the assistance of parallel/successive interference cancellation (PIC/SIC) in the uplink of interleaved orthogonal frequency division multiple access (OFDMA) systems. For every transmitted symbol, PIC is first invoked to remove the multiple user interference (MUI). Thereafter, SIC is employed to successively alleviate the soft-decision outputs of inter-carrier interference (ICI). To fully mitigate the decision residues as well as the interference caused by the undetected symbols, an oblique projection based detector is devised. Furthermore, for practical implementations, a low-complexity version, which only copes with the principal components of ICI, is also addressed. Simulation results show that the performance of the proposed scheme outperforms the existing detection algorithms. Especially, the low-complexity implementation requires dramatically lower computational overhead with only slight performance loss.