Nowadays and in the future, wireless communication system obliged for high
speed data rate and voice transmission, good bandwidth efficiency and also have a
reliable ability through the channel condition which have multipath fading effect.
Mobile communication system Multi-Carrier CDMA (MC-CDMA) is a combination
between multicarrier modulation technique and spread spectrum technologies
(CDMA), MC-CDMA as a wireless digital communication system trusted to have
good reliability in multipath propagation and good to overcoming frequency selective
fading. MC-CDMA also good to increase spectral efficiency using orthogonal carrier.
In generally, communication systems have 3 components, there are transmitter,
receiver, and transmittion media (channel). MC-CDMA system, in the receiver side
need combiner block that good to restoring receive signal.
This final task have been analysed the comparison between linier adaptive
combining scheme and non linier adaptive combining scheme. Linier adaptive
combining using RLS (Recursive Least Square) algorithm and LMS (Least Mean
Square) algorithm. Whereas non-linier adaptive combining using DFE-LMS
(Decision Feedback Equalizer-LMS) algorithm. The purpose of this final task is to
know about the performance and convergence of RLS, LMS dan DFE-LMS method.
Convergence rate, Mean Square Error (MSE) and Bit Error Rate were the main
parameter in analyzing adaptive combining algorithm.
From simulation result using 64 subcarrier in AWGN or Rayleigh channel to
get BER = 10
than DFE-LMS algorithm or RLS algorithm. In AWGN channel, RLS scheme need
SNR = 5.6 dB to get BER = 10
need SNR = 4.6 dB. While in Rayleigh channel, RLS scheme need SNR =8.7 dB, LMS
scheme need SNR = 7.6 dB and DFE-LMS need SNR = 6.6 dB. But in Convergence
rate, RLS scheme give the fastest convergence rate than LMS scheme and DFE-LMS
scheme. RLS scheme need 110 iteration to convergent, LMS scheme need 600
iteration and DFE-LMS need 900 itertation.