Uplink Channel Estimation for Multiuser Fiber-Wireless Systems Using Ternary Signals

Channel estimation in fiber-wireless (Fi-Wi) systems is more challenging compared to conventional communication systems as multipath dispersion introduced by the wireless channel is coupled with nonlinear distortion caused by the radio-over-fiber link. In a multiuser environment, multiple access interference (MAI) poses another challenge as it can significantly degrade system performance. A novel scheme to estimate multiuser Fi-Wi uplink channel using uncorrelated ternary pseudo-random signals is proposed. By exploiting proper harmonic suppression through signal design, the effects of nonlinear distortion and MAI can be eliminated or reduced.