Abstract: This paper gives the comparison of the Bit error rates of modulation techniques like QAM and PSK for their different order of modulations (M) and for different values of subcarriers (N) by using LS channelestimator. Comparison of bit error rates of various modulation schemes is done to find out the best suited modulation technique for transmitting N no. of subcarriers. LS estimator is a technique used for channel estimation in MIMO-OFDM system. Channel estimation is done at the receiver for compensating the effect of distortions which are created by the channel. LS channel estimator comes under the block type channel estimation technique.

Keywords: channel estimation; modulation schemes; MIMO; OFDM; MIMO-OFDM; LS estimator; QAM; PSK.