Efficiency Analysis of a Truncated Flip-FBMC in Burst Optical Transmission

A novel Flip-filter bank multicarrier (Flip-FBMC)-based transmultiplexer (TMUX) with offset quadrature amplitude modulation is proposed to enhance the transmission performance compared to a conventional Flip-OFDM system. Moreover, the possibility to reduce the TMUX response (latency) and increase spectral efficiency is investigated for the first time through a tail shortening method. The proposed design is based on a biorthogonal form for visible light communication (VLC) to increase the flexibility of design requirements. However, spectral efficiency suffers from the ramp-up and the ramp-down at the beginning and end, respectively, of a data burst. Hence, as a penalty, Flip-FBMC imposes 9 more symbols than a Flip-OFDM packet and two factors compared to a DCO-FBMC burst. Hard truncation of the lowest energy tail minimizes latency and limits the system penalty to 2.5 symbols, which is lower than that of DCO-FBCM by 2 symbols. The results show that the prototype filter of the Heisenberg factor ( $\approx 1$ ) is highly effective in reducing the energy loss of truncated tails and reduces the symbol error rate (SER). The Flip-FBMC gain over a direct line-of-sight VLC channel is analyzed, and the channel estimation of a truncated burst, which is based on the interference approximation method (IAM) of IAM-C type, exhibits a superior performance of 1.5 dB at 10−3 SER over the IAM-R method and 1 dB at 10−5 SNR over a cyclic prefix of 1 point Flip-OFDM. On the other hand, the analysis reveals that IAM-C is slightly impacted by the truncated burst compared to the nontruncated version