Analysis of frequency diversity in MC-CDMA systems under correlated fading channels

MC-CDMA can obtain a good frequency diversity effect through spreading and despreading operation in frequency domain. In this paper, the impact of channel parameters to inherent frequency diversity is analyzed at first. Then, three spreading methods to achieve the frequency diversity are investigated. Not only frequency diversity but also multiple-user interference (MUI) is taken into account in our analysis. The achieved frequency diversity gains with different spreading methods are also affected by the combining schemes at the receivers when there are multiple users in the systems.

I. INTRODUCTION

The amazing increase of Internet services and electrics commercial is a strong demand for higher data ratecommunication services not only in fixed network but also in the mobile communication systems. MC-CDMA, which is based on orthogonal frequency division multiplexing(OFDM), can not only solve the difficult multipath environment problem but also have good frequency efficiency and easy implementation[1]–[3].