Information rates of optical impulse modulation over indoor diffuse wireless channels

Optical impulse modulation (OIM) is a recent wireless optical modulation scheme that achieves high data rates by utilizing high-frequency bands to satisfy the channel non-negativity constraint. These bands are attenuated by the lowpass indoor diffuse optical wireless channel, and hence are not detected by the receiver. For a uniform binary input distribution, the information rates are investigated for OIM and compared to those of a conventional rectangular on-off keying (Rect-OOK) scheme. Using a well-known exponential model for the indoor diffuse optical channel, at a normalized delay spread of 0.3 and optical signal-to-noise ratio (SNR) of 3 dBo, the information rate of OIM with a simple lowpass receiver is shown to be 8.6% higher than that of Rect-OOK with a more complex whitened matched filter receiver.