3 research outputs found

    Waveform Design Considerations for 5G Wireless Networks

    Get PDF
    In this chapter, we first introduce new requirements of 5G wireless network and its differences from past generations. The question “Why do we need new waveforms?” is answered in these respects. In the following sections, time‐frequency (TF) lattice structure, pulse shaping, and multicarrier schemes are discussed in detail. TF lattice structures give information about TF localization of the pulse shape of employed filters. The structures are examined for multicarrier, single‐carrier, time‐division, and frequency‐division multiplexing schemes, comparatively. Dispersion on time and frequency response of these filters may cause interference among symbols and carriers. Thus, effects of different pulse shapes, their corresponding transceiver structures, and trade‐offs are given. Finally, performance evaluations of the selected waveform structures for 5G wireless communication systems are discussed

    Enhanced physical layer security by OFDM signal transmission in fractional Fourier domains

    No full text
    The main idea of physical layer security for wireless communications is making the transmitted signal as meaningless for eavesdroppers. It can be achieved by signal processing techniques. In this study, fractional Fourier transform is used for secure communication. Transmitted signal is divided to equal and random intervals, then each interval was taken fractional Fourier transform with four degrees. In this way, signals can be transmitted with an angle between time and frequency domain. Receiver needs to know which angular parameters are used in each interval for obtaining the signal correctly. It is difficult to obtain signals by eavesdropper without any parameter knowledge. In this study, the bit error rate performances of legitimate users and eavesdropper are compared and the bit error rate performance of eavesdropper becomes close to 0,5
    corecore