| Multicarrier code division multiple access (MC-CDMA) combines both orthogonal frequency division multiplexing (OFDM) and code division multiple access (CDMA) techniques. It inherits the advantages of these two techniques. However, like the OFDM system, transmitted signal of MC-CDMA system suffers from the high peak-to-average power ratio (PAPR) as well.;As a good solution to reduce the high peak-to-average pmver ratio (PAPR), Golay complementary sequences have been employed in multicarrier communication systems. In this thesis, we present a simple but novel technique to analyse the theoretical PAPR bounds of downlink MC-CDMA system using Golay complementary sequences for spreading and/or coding. We first develop the PAPR bounds of uncoded MC-CDMA system using binary Golay complementary spreading sequences. Then, we develop the PAPR bounds when each user's transmitted data is encoded as QPSK Golay sequences or 16-QAM Golay sequences. Simulation results demonstrate that the theoretical PAPR bounds and 99.9% PAPRs are independent of the spreading factor for uncoded case. For coded case, the theoretical PAPR bounds and 99.9% PAPRs are independent of the number of spreading processes as well as the spreading factor. Practically, the independency shows that G olay complementary sequences are useful for peak povver control in downlink MC-CDMA system. |
