Equalizers for PCC-OFDM with overlapping symbol periods

Polynomial cancellation coded orthogonal frequency division multiplexing (PCC-OFDM) with overlapping symbol periods is a modulation technique which overcomes many of the disadvantages of OFDM. Overlap PCC-OFDM is much less sensitive to frequency offset and Doppler spread and has better performance in channels with long delay spread than OFDM. This paper analyzes the equalizers that are required. Results are presented for linear and decision feedback equalizers of varying length in the presence of additive white Gaussian noise. The performance is degraded by two effects: the nonorthogonality of the basis functions, and the limited span of the equalizers. Despite these effects, for the same bandwidth efficiency overlap PCC-OFDM systems can be designed to have similar performance to OFDM with a cyclic prefix even when the only channel impairment is noise.