Equalization for infrared wireless systems using OOK-CDMA

We evaluate the performance of indoor infrared wireless systems using on-off keying code-division multiple-access (OOK-CDMA) systems with three kinds of equalizers: decision-feedback equalizer (DFE), decision-feedforward-and-feedback equalizer (DFFE), and feedforward equalizer (FE). To estimate the impulse response, we use the training sequence that alternates '1' and '0' sequentially. Among three kinds of equalizers, we show that the system with the DFFE can achieve the best performance at high bit rate. When the bit rate is low or the transmitted optical power is low, the system with the FE achieves the best performance.