Spectral analysis of convolutional coded DPIM for indoor optical wireless communications

Power spectral density (PSD) of the convolutional coded digital pulse interval modulation (CC-DPIM) is derived analytically based on the stationarization of variable-length word sequence (VLWS). To verify the theoretical model developed, CC-DPIM is simulated in Matlab and its spectrum is compared with the predicted results showing a close match. As in DPIM scheme, CCDPIM spectrum also contains a distinct slot (clock) component which can be recovered at the receiver for both slot and symbol synchronization.