Peak power analysis of MC-CDMA employing Golay complementary sequences
Abstract
l\!Iulticarrier code division multiple access (MC-CDMA) combines
both orthogonal frequency division multiplexing (OFDM) and code
division multiple access (CD lVIA) techniques. It inherits the advantages
of these two techniques. However, like the OFDM system,
transmitted signal of rv1C-CDl'v1A system suffers from the high peakto-
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 l'v1C-CDMA system using Golay complementary sequences
for spreading and/ or coding. \Ve first develop the PAPR bounds
of uncoded IVIC-CDMA system using binary Golay complementary
spreading sequences. Then, we develop the PAPR b ounds when each
user's transmitted data is encoded as QPSK Golay sequences or 16-
QAI'vl Golay sequences. Simulation results demonstrate that the
theoretical PAP R 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.