Query: F-OFDM

title: A Low Complex SVD Based F OFDM
abstract: As an approach to reduce the computational complexity of Filtered Orthogonal Frequency Division Multiplexing (F OFDM) we removed restrictions on filter lengths in F OFDM and then applied linear pre and post processing for a transmitter and receiver using the singular value decomposition (SVD) method in order to solve the data distortion caused by the use of filter lengths much shorter than the symbol duration. This new F OFDM has been given the designation SVD based F OFDM (SF OFDM) Numerical results show that SF OFDM has much lower complexity than F OFDM, especially when transmitting small numbers of resource blocks. SF OFDM also has nearly the same bit error rate performance as conventional F OFDM. Moreover, SF OFDM retains a much lower out of band emission than cyclic prefix (CP) OFDM, while at the same time having a similar level of peak to average power ratio compared to CP OFDM.

title: Uplink Interference Analysis of F OFDM Systems Under Non Ideal Synchronization
abstract: Filtered orthogonal frequency division multiplexing (f OFDM) is considered one of the candidates for future mobile communication because of its flexible parameter configuration for different scenarios. However, the interference analysis of f OFDM is considerably challenging due to its special transceiver structure, especially in the uplink with non ideal synchronization. The uplink interference of f OFDM systems under non ideal synchronization, in which carrier frequency offset (CFO) and timing offset (TO) of multiple user equipment (UE) are considered, is investigated in this study. The interference is classified into several sub interferences. The closed form expressions of each sub interference and its variance are first derived, and then verified via simulations. On the basis of the derived closed form expressions, first, the influences of non ideal factors and system parameters, such as CFO, TO, guard band (GB) and subcarrier spacing (SCS) on the uplink interference of f OFDM systems, are simulated and analyzed. This study is verified by computer simulations, and the theoretical derivation of interference agrees with the simulation result. Second, Hanning window filters are employed by previous f OFDM systems, resulting in bit error rate (BER) imbalance between sub bands. Hence, the effect of waveform filter on the interference and BER is also investigated in this research. Results indicate that better interference and BER performances than Hanning window filters can be obtained by employing reasonable filter settings. Furthermore, several filter design rules are concluded. Overall, the analysis and simulations reveal many intrinsic interference characteristics of f OFDM, which will benefit the future f OFDM system designs.

title: Resource Allocation in f OFDM Wireless Networks with Delay Estimation Using Service Curve and Envelope Process
abstract: In this paper, a resource allocation algorithm for wireless communication systems is proposed, which considers the channel transmission quality and data delay. In the proposed approach, the delay value is estimated to decide on the allocation of available radio resources, aiming to reduce the system's average delay. For the delay estimation, an approach involving concepts of Network Calculus such as service curve and envelope process MFBAP (Multifractal Bounded Arrival Process) is proposed. In view of the recent techniques for 5G communication systems, f OFDM (filtered Orthogonal Frequency Division Multiplexing) technology is also considered in our simulation scenarios. Simulations are carried out to compare the performance of the resource allocation algorithms in terms of QoS (Quality of Service) parameters such as average delay, throughput, processing time, loss rate and fairness index, proving the efficiency of the proposed algorithm.

title: A new hybrid approach for reducing the high PAPR in OFDM and F OFDM systems with low complexity
abstract: The large (peak to average power ratio (PAPR) phenomenon is a downside in filtered multiplexing of the orthogonal frequency division (F OFDM Beyond 5G candidate) because of the nonlinearity design of the transmitter. Recently, several hybrid approaches have been implemented to minimize the high value of PAPR, at the expense of increasing the level of computational complexity in the system. In this paper, a new hybrid approach has been introduced throughout parallel to combine the approach of selective mapping (SLM) with the approach of partial transmit sequence (PTS) with (CSS) to improve the efficiency of PAPR reduction with lower complexity in numerical methods. The results indicate that the F OFDM systems with the proposed hybrid method have superior performance compared to existing hybrid methods in terms of PAPR reduction, side information, and computational complexity. Furthermore, a new hybrid approach suggested preserving the BER and PSD efficiency without deterioration.

title: Research on F OFDM Subband Filter Algorithm for Three Major 5G Application Scenarios
abstract: With the proposal of three major 5G (5th generation wireless systems) application scenarios, the first NR (New Radio) specification version of 3GPP (3rd Generation Partnership Project) NR Release 15 was released in June 2018. The waveform technology in this version continues to use CP OFDM (Cyclic Prefixed Orthogonal Frequency Division Multiplexing) of LTE, mainly for eMBB (Enhanced Mobile Broadband) F OFDM (Filtered Orthogonal Frequency Division Multiplexing) which has been used as a candidate waveform technology for 5G, still has a large development space in performance optimization. In this paper, algorithm research and design are carried out for F OFDM subband filter in three 5G application scenarios. Through MATLAB simulation results show that compared with the corresponding scenario of OFDM, the tri subband F OFDM system matched with the subband filter respectively can not only suppress the out of band emission, improving the spectrum utilization and the performance of asynchronous transmission, but also improve the bit error rate and the reliability of the system.

title: Resource Allocation in f OFDM Wireless Networks with Delay Estimation Using Service Curve and Envelope Process
abstract: In this paper, a resource allocation algorithm for wireless communication systems is proposed, which considers the channel transmission quality and data delay. In the proposed approach, the delay value is estimated to decide on the allocation of available radio resources, aiming to reduce the system's average delay. For the delay estimation, an approach involving concepts of Network Calculus such as service curve and envelope process MFBAP (Multifractal Bounded Arrival Process) is proposed. In view of the recent techniques for 5G communication systems, f OFDM (filtered Orthogonal Frequency Division Multiplexing) technology is also considered in our simulation scenarios. Simulations are carried out to compare the performance of the resource allocation algorithms in terms of QoS (Quality of Service) parameters such as average delay, throughput, processing time, loss rate and fairness index, proving the efficiency of the proposed algorithm.

title: UFMC and f OFDM: Contender Waveforms of 5G Wireless Communication System
abstract: Because of the increased demand for high data rates, looking for using new technologies that meet these requirements are considered a necessary. Hence, Fifth Generation (5G) is expected to be impressive in offering these requirements and implement around 2020. Orthogonal Frequency Division Multiplexing (OFDM) is considered a main technology of LTE wireless communication standards. Due to its suffering from high Bit Error Rate (BER) and Peak Average Power Ratio (PAPR) OFDM doesn't consider as charming solution for future wireless communications and several emerging applications of 5G. Moreover, high Out of Band Emission (OOBE) and inability of supporting the flexible numerology are other demerits of OFDM systems. Thus, looking for alternative waveforms which have the ability of solving OFDM disadvantages are necessary to introduce it as contender candidate for 5G wireless communication systems. In this paper, both of Filtered OFDM (f OFDM) and Universal Filtered Multi carrier (UFMC) systems have been discussed for 5G wireless communication systems and compared to OFDM system. The results showed that f OFDM system is better than both OFDM and UFMC systems and could be introducing as competitive candidate for 5G wireless communication systems because of its ability of reducing OOBE and enhancing BER performance.

title: Performance Analysis of OFDM, W OFDM and F OFDM Under Rayleigh Fading Channel for 5G Wireless Communication
abstract: The OFDM multiple carrier modulations are more secure and suitable for a special fading that is known as a frequency selective fading. To minimize the queue in the 5G waveform, it is likewise much important to resize the bandwidth in the OFDM based technology. Consequently, Filtered Orthogonal Frequency Division Multiplexing also known as a spectrally localized waveform technology which is the primary approach. Windowed OFDM (W OFDM) where each symbol is categorized by windowed and every symbol is overlapped in the special time domain that is known as the classical OFDM scheme. The traffic scenario is processed by the individual sub bands. This article presents the comparison of the performance analysis of OFDM, W OFDM, and F OFDM systems using BPSK, QAM, 16 PSK, 8 QAM, QPSK, and 16 QAM modulation techniques under Rayleigh fading channel. The main aim of this article is to focus on examining the effective performance of OFDM, W OFDM, and F OFDM in terms of PSD, Bit error rate, and signal to noise ratio. The simulated values are analyzed in terms of PSD and BER.

title: Resource Virtualization and Allocation for TDD F OFDM Systems With MU MIMO
abstract: Wireless resource virtualization scheme has been proposed to satisfy the quality of service (QoS) requirement of multi service traffic flows on multi dimensional resources. However, it is a challenge to design an appropriate virtual resource allocation strategy for multi dimensional resource to meet the delay demand of multi service. In this paper, we study the virtual resource allocation method in TDD F OFDM system with MU MIMO and formulate the multi service virtual resource optimization problem as a cross layer problem. Then, we develop an effective dynamic algorithm with an iterative dual update to meet the optimization targets of the Media Access Control (MAC) layer and physical layer. Finally, the simulation results show that our proposed virtual resource allocation algorithm not only achieves better spectral efficiency and flow access ratio, but also guarantees the delay requirements of multi service flows.

title: A Unified Spectrum Formulation for OFDM, FBMC, and F OFDM
abstract: Although orthogonal frequency division multiplexing (OFDM) has been standardized for 5G, filter bank multi carrier (FBMC) and filtered orthogonal frequency division multiplexing (F OFDM) remain competitive as candidates for future generations of wireless technologies beyond 5G, due to their reduced spectrum leakage and thus enhanced spectrum efficiency. In this article, we developed a unified spectrum expression for OFDM, FBMC, and F OFDM, which provides comparative insights into those techniques. A representative sideband quantification is included at the end of this article.