Non-coherent detection for ultraviolet communications with inter-symbol interference

Ultraviolet communication (UVC) serves as a promising supplement to share the responsibility for the overloads in conventional wireless communication systems. One challenge for UVC lies in inter-symbol-interference (ISI), which combined with the ambient noise, contaminates the received signals and thereby deteriorates the communication accuracy. Existing coherent signal detection schemes (e.g. maximum likelihood sequence detection, MLSD) require channel state information (CSI) to compensate the channel ISI effect, thereby falling into either a long overhead and large computational complexity, or poor CSI acquisition that further hinders the detection performance. Non-coherent schemes for UVC, although capable of reducing the complexity, cannot provide high detection accuracy in the face of ISI. In this work, we propose a novel non-coherent paradigm via the exploration of the UV signal features that are insensitive to the ISI. By optimally weighting and combining the extracted features to minimize the bit error rate (BER), the optimally-weighted non-coherent detection (OWNCD) is proposed, which converts the signal detection with ISI into a binary detection framework with a heuristic decision threshold. As such, the proposed OWNCD avoids the complex CSI estimation and guarantees the detection accuracy. Compared to the state-of-the-art MLSD in the cases of static and time-varying CSI, the proposed OWNCD can gain ∼1 dB and 8 dB in signal-to-noise-ratio (SNR) at the 7% overhead FEC limit (BER of 4.5×10 −3 , respectively, and can also reduce the computational complexity by 4 order of magnitud

Time varying ISI model for nonlinear interference noise

We show that the effect of nonlinear interference in WDM systems is equivalent to slowly varying inter-symbol-interference (ISI), and hence its cancellation can be carried out by means of adaptive linear filtering. We characterize the ISI coefficients and discuss the potential gain following from their cancellation.Comment: Submitted to the optical fiber communication conference (OFC), 201

Pengaruh Dispersi Terhadap Kecepatan Data Komunikasi Optik Menggunakan Pengkodean Return to Zero (RZ) Dan Non Return to Zero (NRZ)

Fiber optic has characteristics for optical transmission system. One of optical characteristics is pulse broadening, known as dispersion. The dispersion is a condition where pulse in output side is larger than pulse in input side. It means that pulse broadening had happened. In the communication system, it\u27s known as inter symbol interference (ISI). Effect of Inter symbol interference increasing the error bit or BER value. In optical communication system, dispersion is most influence to the data rate that fiber can support. Besides, bandwidth, information capacity, transmission distance, wavelength and fiber type can also influenced by the dispersion.&nbsp