Equalization of Multicarrier Cognitive Radio Transmissions over Multipath Channels with Large Delay Spread

Abstract

This paper investigate the channel equalization problem in opportunistic white space communication systems, with an emphasis on transmission over channels with high delay spread. We consider the equalization problems of Orthogonal Frequency Division Multiplexing (OFDM) and three alternative multicarrier modulation schemes, namely DFT-spread OFDM (DFTS-OFDM), Constant Envelope OFDM (CE-OFDM) and Filter Bank Multicarrier (FBMC). After a brief description of these schemes, we show their performance assuming frequency domain per subcarrier minimum mean square error (MMSE) channel equalization. The simulations are performed using the channel parameters specified in the IEEE 802.22 standard. We show that bit error rate (BER) performance of FBMC and DFTS-OFDM are comparable to OFDM in frequency selective channels which make them a very strong candidate for cognitive applications.