Adaptive Soft-Decision Aided Differential Modulation for Cooperative Uplink Transmission Relying on Radio-Over-Fiber Backhaul

A novel adaptive turbo-coded soft-decision aided differential detection (ATSDD) scheme is proposed for cooperative uplink wireless and Radio-over-fiber (ROF) transmission in a Fractional Frequency Reuse (FFR) based multicell, multiuser system. More specifically, the ATSDD scheme is employed by the Mobile Station (MS) for reliably conveying the source bits to a pair of Remote Antennas (RAs) by appropriately adjusting the modulation mode according to the near-instantaneous wireless and ROF channel conditions. The ATSDD switching thresholds are specifically adjusted for ensuring that the Bit Error Ratio (BER) remains below 10^(-5). We also investigated the effect of phase-rotations, which is routinely inflicted by practical imperfect ROF links. We demonstrate that our ATSDD scheme increases the overall throughput.