Investigation of single- and multi-carrier modulation formats for Kramers-Kronig and SSBI iterative cancellation receivers.

The Kramers-Kronig (KK) receiver has recently attracted significant attention due to its capability of field recovery with direct detection. Under minimum phase condition, the KK receiver may use either single- or multi-carrier modulation formats. In this Letter, we investigate the appropriate modulation formats for both KK and signal-signal beat interference (SSBI) iterative cancellation (IC) receivers. It is shown that for the KK receiver, the single-carrier modulation format is superior to orthogonal frequency division multiplexing (OFDM), because the multi-carrier nature of OFDM signals increases the peak-to-average power ratio, which causes a violation of minimum phase condition. For the IC receiver, SSBI cancellation is more effective when the OFDM modulation format is adopted; thus, OFDM is the better fit for IC receivers than single carrier.