Post coded OFDM systems with SVM detector

Post coded OFDM systems with SVM detector S.Madhuranthagi*,M.S.Karthikeyan*,S.Brahadeesh*,S.Kartik*,N.S.Vignesh*,N.Kathiresan*,P.Sudheesh# * Student,Department of ECE,Amrita Vishwa Vidyapeetham,Ettimadai,Coimbatore-641105 #Assistant Professor, Department of ECE,Amrita Vishwa Vidyapeetham,Ettimadai,Coimbatore-641105

Abstract— Orthogonal Frequency Division Multiplexing (OFDM) is well known as a highly spectral efficient transmission scheme capable of dealing with severe channel impairments encountered in mobile environment. This paper discusses the design and analysis of post coded OFDM (PC-OFDM) systems. We show that PC- OFDM systems are a special case of precoded OFDM systems that offer advantageous complexity-performance trade-offs to overcome the symbol recovery problem in uncoded OFDM systems. In particular, PC-OFDM systems introduce frequency diversity by manipulating the OFDM symbols in the time domain so that the computational complexity of the system can be significantly reduced. We discuss the design principles of PC-OFDM transmitter that uses upsampling operation and the spreading codes to introduce frequency diversity. We also describe the design of low-complexity receiver for PC-OFDM systems. SVM detector is used for high performance.

Keywords— Orthogonal frequency division multiplexing (OFDM), precoding, post-coding, spreading codes, frequency diversity, pulsed OFDM, coding gain, diversity gain.
Introduction
Orthogonal frequency-division multiplexing (OFDM) has been proven to be a viable technique to overcome multipath fading in wireless channels. While OFDM systems convert a multipath fading channel into a series of equivalent flat fading channels,

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