Performance analysis of OFDM-IM scheme under STO and CFO

In this letter, performance analysis of orthogonal frequency division multiplexing with index modulation (OFDM-IM) is presented in term of bit error rate (BERs). The analysis considers its performance under two impairments, symbol time offset (STO) and carrier frequency offset (CFO) in frequency-selective fading channel. As orthogonal multicarrier system, OFDM-IM is subject to both inter-symbol interference (ISI) and inter-carrier interference (ICI) in a frequency-selective fading channel. OFDM-IM is a new multicarrier communication system, where the active subcarriers indices are used to carry additional bits of information. In general, in the previous existing works, OFDM-IM are evaluated only for near-ideal communication scenarios by only incorporating the CFO factor. In this work, the OFDM-IM performance is investigated and compared with conventional OFDM in the presence of two impairments, STO and CFO. Simulation results show that OFDM-IM outperforms the conventional OFDM with the presence of STO and CFO, especially at high SNR areas.

Orthogonal Frequency Division Multiplexing and Code Division Multiple Access Systems

Chapter 8 presents modern multi-user and multicarrier communication systems based on code division multiple access technology and orthogonal frequency division multiple access technology. Analogue, digital, and discrete orthogonal frequency division multiple access systems are presented separately and then inter-related from theoretical and practical points of view. A precise mathematical model of discrete baseband and intermediate-frequency blocks is presented, including procedures for signal mapping and the discrete Fourier transform, and then related to the model of an analogue radiofrequency block to make the whole orthogonal frequency division multiple access system. The basic theory of binary and non-binary code division multiple access systems operation is presented. To support deeper theoretical understanding of the design and operation of a code division multiple access system, one project in the supplementary material demonstrates the mathematical modelling, simulation, and design of this system in field-programmable gate array technology and presents the development tools required.

FBMC + Security – A New Candidate for 5G

Recent researches and discussions stress the need for waveforms with better spectral efficiency which could be obtained by Orthogonal Frequency Division Multiplexing (OFDM). OFDM supports multicarrier communication and is capable of mitigating Inter Symbol Interference. Hence there is no need of equalizer at the receiving side. Human life has become easy and comfortable due to the rapid of wireless technology. At the same time there is an increase in the number of malicious users and the threat created by them for secure data transmission is noteworthy. Hence this work aims at to provide a solution which could solve the above discussed issues. Filter banks with multicarrier communication systems has gained popularity because of its capability to overcome the spectral leakage. Hence filter banks are placed instead of cyclic prefix. Near perfect reconstruction filter has been utilized to reduce the leakage. Further, Secure data transmission is accomplished by means of authentication tag. Pseudo Noise (PN) sequence named XOROSHIRO has been generated and appended with the information to be transmitted. At the receiving end only the information with authentication tag is accepted and the rest are omitted. FBMC system together with the authentication tag improves the spectral efficiency and also ensures safe and successful communication.