Abstract:The performance of infrared wireless synchronous Code Division Multiple Ac-cess(CDMA) with Pulse Position Modulation(PPM) signaling systems without optical hard limiter and with optical hard limiter using modified prime sequence codes as signature codes is analyzed. The upper bound on the bit error probability of systems without optical hard limiter and with optical hard limiter are derived taking into account the effect of multiple-user interference, the photodetector shot noise and thermal noise. Numerical results show that the performance of systems with optical hard limiter is superior to that without optical hard limiter.