Novel Scheduling Algorithm for 3GPP Downlink LTE Cellular Network

AbstractLong Term Evolution is standardized by the 3rd Generation Partnership Project to provide a high data rate up to 100 Mbps and 50 Mbps for downlink and uplink transmission respectively and can operate in different bandwidths ranging from 1.4MHz up to 20MHz. The incorporated scheduling mechanisms can significantly contribute to this goal. Scheduling mechanism is the process of allocated the resources (Time and Frequency) to users transmitting different flows in same time. In this paper, a novel scheduling algorithm is presented, modeled and compare to basic scheduler used in downlink LTE transmission, such as Round Robin, Max Rate and Proportional fair schedulers. Simulation results, presented in this paper, show that the newly proposed algorithm improves system capacity as compare with Proportional Fair scheduler with guaranty of 80% fairness between all users

Fiber Nonlinearity Equalizer Based on Support Vector Classification for Coherent Optical OFDM

A support vector machine (SVM)-based classification nonlinear equalizer (NLE) is demonstrated, for the first time, in coherent optical orthogonal frequency-division multiplexing (CO-OFDM). For a 40-Gb/s 16 quadrature amplitude modulated (16QAM) CO-OFDM system at 400 km of transmission, SVM-NLE reduces the fiber-induced nonlinearity penalty by about 1 dB in comparison to the benchmark artificial-neural-network (ANN)-based and inverse-Volterra-series-transfer-function-based NLEs

Performance Assessment of Dual-Polarized 5G Waveforms and Beyond in Directly Modulated DFB-Laser using Volterra Equalizer

International audienceWe investigate the performance of 25-Gbps dual-polarized orthogonal frequency division multiplexing (OFDM)-based modulation in a directly modulated distributed feedback (DFB)-laser over 25 km of single-mode fiber. A Volterra equalizer is used to compensate for the nonlinear effects of the optical fiber. The results show that FBMC-OQAM modulation outperforms OFDM, universal filtered multicarrier (UFMC), and generalized frequency division multiplexing (GFDM) waveforms. Indeed, a target bit error rate of similar to 3.8 x 10(-3) [forward error correction (FEC) limit] for FBMC, UFMC, OFDM, and GFDM can be achieved at -30.5, -26, -16, and -14.9 dBm, respectively. The effect of the DFB laser is also investigated for UFMC, OFDM, and GFDM, and they undergo a Q penalty of 2.44, 2.77, and 4.14 dB, respectively, at their FEC limit points. For FBMC-OQAM, the signal is perfectly recovered when excluding the DFB laser at -30.5 dBm. (C) 2020 Society of Photo-Optical Instrumentation Engineers (SPIE

Reduction of Nonlinear Intersubcarrier Intermixing in Coherent Optical OFDM by a Fast Newton-Based Support Vector Machine Nonlinear Equalizer

A fast Newton-based support vector machine (N-SVM) nonlinear equalizer (NLE) is experimentally demonstrated, for the first time, in 40 Gb/s 16-quadrature amplitude modulated coherent optical orthogonal frequency division multiplexing at 2000 km of transmission. It is shown that N-SVM-NLE extends the optimum launched optical power by 2 dB compared to the benchmark Volterra-based NLE. The performance improvement by N-SVM is due to its ability of tackling both deterministic fiber-induced nonlinear effects and the interaction between nonlinearities and stochastic noises (e.g., polarization-mode dispersion). An N-SVM is more tolerant to intersubcarrier nonlinear crosstalk effects than Volterra-based NLE, especially when applied across all subcarriers simultaneously. In contrast to the conventional SVM, the proposed algorithm is of reduced classifier complexity offering lower computational load and execution time. For a low C-parameter of 4 (a penalty parameter related to complexity), an execution time of 1.6 s is required for N-SVM to effectively mitigate nonlinearities. Compared to conventional SVM, the computational load of N-SVM is ∼6 times lower

Comparison of DSP-based nonlinear equalizers for intra-channel nonlinearity compensation in coherent optical OFDM

A novel versatile digital signal processing (DSP)-based equalizer using support vector machine regression (SVR) is proposed for 16-quadrature amplitude modulated (16-QAM) coherent optical orthogonal frequency-division multiplexing (CO-OFDM) and experimentally compared to traditional DSP-based deterministic fiber-induced nonlinearity equalizers (NLEs), namely the full-field digital back-propagation (DBP) and the inverse Volterra series transfer function-based NLE (V-NLE). For a 40 Gb/s 16-QAM CO-OFDM at 2000 km, SVR-NLE extends the optimum launched optical power (LOP) by 4 dB compared to V-NLE by means of reduction of fiber nonlinearity. In comparison to full-field DBP at a LOP of 6 dBm, SVR-NLE outperforms by ∼1 dB in Q-factor. In addition, SVR-NLE is the most computational efficient DSP-NLE

Performance of window synchronisation in coherent optical ofdm system

Abstract—In this paper we investigate the performances of a robust and efficient technique for frame/symbol timing synchronization in coherent optical OFDM. It uses a preamble consisting of only two training symbol with two identical parts to achieve reliable synchronization schemes. The performances of the timing offset estimator at correct and incorrect timing in coherent optical OFDM are compared in term of mean and variance of the timing offset, and finally, we study the influence of number of subcarriers and chromatic dispersion. Keywords—COFDM; timing offset; time synchronization; training symbol) I

Performance evaluation of optical network-on-chip based on MIMO system

When designing Optical Networks-On-Chip, designers have resorted to make dialogue between emitters (lasers) and receivers (photo-detectors) through a waveguide which is based mainly on optical routers called lambda-router. In this document, we propose a new method based on the multiple concepts of Inputs and Output, and we give a model of the channel propagation, then we discuss the MIMO CDMA systems to assess its performance. For this we present the family of code used and we develop the receiver algorithm of such systems. Finally, we present simulations to validate the presented system