Behavior and Techniques for Improving Performance of OFDM Systems for Wireless communications

Abstract

Orthogonal frequency division multiplexing (OFDM) is a special case of multicarrier transmission which transmits a stream of data over a number of lower data rate subcarriers. OFDM splits the total transmission bandwidth into a number of orthogonal and non-overlapping subcarriers and transmit the collection of bits called symbols in parallel using these subcarriers. This paper gives a total insight of various Peak -to Average Power Reduction (PAPR) techniques and principles of OFDM systems used in wireless communications. The research paper places a focus also on OFDM behaviors and techniques like Carrier Frequency Offset (CFO) estimation that improves performance of OFDM for wireless communications. Finally, the paper provides a number of wireless communication standards and many of the applications where OFDM systems are used.

A 500 km Long Transmission with Coherent Optical OFDM Using Dual Polarization Quadrature Phase Shift Keying (QPSK) and Double Sideband Suppressed‐Enhanced Carrier (DSS‐EC)

“…Both polarizations "X" and "Y" are taken into the analysis. A comparison of proposed work and reported work [16] is shown in Table 2 in terms of log BER, input OSNR, the technique used, data rate, etc. It is observed that the proposed CO-OFDM-DSS-EC-QPSK is superior to CO-OFDM-QPSK and CO-OFDM-16QAM.…”

“…Similar results at 500 km in CO-OFDM were observed using QPSK [2] and 16 QAM comparisons. [16] In this work, a high-speed 100 Gbps CO-OFDM using a QPSK encoder is investigated with the DSS-EC technique over 500 km uncompensated link distance. Further proposed system is compared with CO-OFDM-QPSK and CO-OFDM-16QAM systems.…”

Interference Mitigation in Wireless Communication – A Tutorial on Spread Spectrum Technology

“…Cognitive radio (CR) is one technique suitable for spectrum management. This system is widely in use and has been found suitable in spectrum sensing, spectrum migration and spectrum sharing [6,7]. The operation and application of CR have been elaborately discussed in [8].…”