Numerical Simulation and Design of Low PAPR FBMC Communication System for 5G Applications

Unlike SC-FDMA (Single-Carrier Frequency Division Multiple Access), merging only DFT (Discrete Fourier Transform) addition with FBMC-OQAM (filter group multi-carrier with offset quadrature amplitude modulation) only cuts the marginal PAPR. (Peak-to-average power ratio). To take advantage of the single carrier effect of DFT extension, special conditions for the coefficients of the IQ (in-phase and quadrature phase) channels of every single subcarrier ought to be met. As a beginning point, we first originate this form, which we call the ITSM (Identical Time-Shifted Multi-Carrier) condition. Then, depending on this condition, we put forward a new FBMC for low PAPR. The foremost features of the offered way out are summarized as: First, to additionally raise the PAPR reduction, we created four candidate versions of the FBMC waveform for DFT spreading out and ITSM conditions and carefully chosen one with the least peak power. Even with various candidate generations, unlike the traditional SI (Side information) based PAPR reduction scheme, the focal computational fragments (such as DFT and IDFT) are shared and need only be executed one time. Therefore, matched to the prior DFT-expanded FBMC, the overhead in complexity is small, and the recommended pattern can realize a PAPR reduction comparable to SC-FDMA. Second, in the projected pattern each one pass on only two bits of SI from a block of FBMC-OQAM symbols. And so, the SI overhead is meaningfully lesser than a conventional SI-based scheme such as SLM (Selective Mapping) or PTS (Partial Transmission Sequence).The whole work is executed using MATLAB software. The PAPR of FBMC system has been significantly reduced after the application of proposed algorithm. PAPR was reduced by 25 % after the use of DFT spreading and ITSM conditioning

Peak Power Reduction in Multicarrier Waveforms

Modern wireless communication systems employ multicarrier waveforms, such as the widely-used Orthogonal Frequency Division Multiplexing (OFDM) and the recent OFDM with Offset-QAM (OFDM/OQAM) schemes. An inherent characteristic of these waveforms is the high Peak-to-Average Power Ratio (PAPR). One of the last stages of the transmitter is the power amplifier, which needs specific attention as a major source of power consumption. For acceptable levels of power efficiency, the high PAPR issue causes distortion to the signal due to the nonlinearity of the power amplifier. This is a major drawback of multicarrier systems and, if not addressed properly, could overcome their advantages. The PAPR reduction has been a topic of research for many years. By introduction of the new generations of the wireless systems, and perseverance of the more complicated multicarrier waveforms in finding their way into the proposed enabling technologies, this problem has gained interest again. Despite the relatively long history of research and the huge available literature, the problem is, to a great extent, still open. Among the disadvantages of the previously suggested PAPR reduction techniques, high computational complexity and complicated adaptation to the schemes such as OFDM/OQAM are standing out. In this thesis, in addition to an in-depth review of the multicarrier waveforms in question, the two aforementioned issues are tackled. The challenges in adaptation of the PTS technique to the OFDM/OQAM are investigated. Concerning the general issue of high computational complexity, the feasibility of using interpolation instead of direct oversampling in PAPR measurement is studied. Depending on the bandwidth configuration, the interpolation could be remarkably beneficial

Submodularity and Its Applications in Wireless Communications

This monograph studies the submodularity in wireless communications and how to use it to enhance or improve the design of the optimization algorithms. The work is done in three different systems. In a cross-layer adaptive modulation problem, we prove the submodularity of the dynamic programming (DP), which contributes to the monotonicity of the optimal transmission policy. The monotonicity is utilized in a policy iteration algorithm to relieve the curse of dimensionality of DP. In addition, we show that the monotonic optimal policy can be determined by a multivariate minimization problem, which can be solved by a discrete simultaneous perturbation stochastic approximation (DSPSA) algorithm. We show that the DSPSA is able to converge to the optimal policy in real time. For the adaptive modulation problem in a network-coded two-way relay channel, a two-player game model is proposed. We prove the supermodularity of this game, which ensures the existence of pure strategy Nash equilibria (PSNEs). We apply the Cournot tatonnement and show that it converges to the extremal, the largest and smallest, PSNEs within a finite number of iterations. We derive the sufficient conditions for the extremal PSNEs to be symmetric and monotonic in the channel signal-to-noise (SNR) ratio. Based on the submodularity of the entropy function, we study the communication for omniscience (CO) problem: how to let all users obtain all the information in a multiple random source via communications. In particular, we consider the minimum sum-rate problem: how to attain omniscience by the minimum total number of communications. The results cover both asymptotic and non-asymptotic models where the transmission rates are real and integral, respectively. We reveal the submodularity of the minimum sum-rate problem and propose polynomial time algorithms for solving it. We discuss the significance and applications of the fundamental partition, the one that gives rise to the minimum sum-rate in the asymptotic model. We also show how to achieve the omniscience in a successive manner